# Layer 5: how we meet the off-site construction requirement Written 13 Sep 2026. Every web source in this file was fetched 13 Sep 2026 unless a different date is written next to it. Sources sit at the end of each section and again in the consolidated list. **What this file is.** Ken asked: "figure how we would meet the offsite." This is the answer. It takes the finding from `docs/montana/03-codes-and-classification.md` section 3.2 (the cast panel is a PANELIZED SYSTEM, which is OFF-SITE CONSTRUCTION, and Montana adopted both ICC/MBI standards effective 21 Sep 2024) and works out what that actually costs Ken, which of three routes to take, and what has to exist in the plant and on paper to take it. **What this file is not.** It does not repeat the statute and rules (`01-statute-and-rules.md`), the permit mechanics and fees (`02-approval-process.md`), the code editions and occupancy classification (`03-codes-and-classification.md`), or the contents of the quality manual (`04-quality-manual-requirements.md`). Section 6 below is a cross-reference table into 04, not a second copy of it. **Rule for reading.** I have not invented a section number, a standard designation, a fee or a requirement. Where I read the actual text I quote it. Where I am reasoning from the text rather than reading a rule that says so, I say so. Anything I could not confirm is marked **NOT CONFIRMED**. A written answer from the Building Codes Bureau beats every word of this file. **One caveat that runs through the whole document.** The ICC/MBI text quoted here comes from the ICC-posted approved ballot drafts of the two standards, not from the purchased published editions: - ICC/MBI 1200-2021: (fetched 13 Sep 2026, 31 pages, full normative text Chapters 1 through 8) - ICC/MBI 1205-2021: (fetched 13 Sep 2026, 36 pages, full normative text Chapters 1 through 8) Both are complete standard texts, not summaries. I read the sections quoted below directly out of those PDFs. Montana adopted the **published 2021 editions** at ARM 24.301.1203, so **buy both from ICC and check every section number in this file against the published text before anything goes in a submittal.** That is open item 1 in `04-quality-manual-requirements.md` section 10 and it is still open. The NEEP copy of ICC/MBI 1205 named in the task brief (, fetched 13 Sep 2026) is **not** the standard. It is a three-page NEEP explainer about the standard. It is useful background and it is cited once below, but nothing normative comes from it. --- ## 0. The answer in one page Montana's factory-built building rules look like they are written only for whole modules. They are not. The chain that puts Ken's panel line inside the Montana system runs through five links, and every link is text I read: | # | The link | Where it says so | |---|---|---| | 1 | The cast panel is a **PANELIZED SYSTEM** | ICC/MBI 1200 and 1205 §202: "Wall, roof or floor components that are constructed at a location other than the building site in a manner that prevents the construction from being inspected at the building site without disassembly, damage or destruction thereof" | | 2 | A panelized system **is a modular component** | 1205 §202 MODULAR COMPONENT: "A sub-assembly, subsystem, or combination of elements, **including panelized systems**, building shells or bathroom pods, for use as a part of a modular building that is not structurally independent, but is a part of structural, plumbing, mechanical, electrical, fire protection, or other systems affecting life safety" | | 3 | A maker of panelized systems **is a manufacturer** | 1205 §202 MANUFACTURER: "The entity responsible for the manufacturing of assemblies, **panelized systems**, modular buildings, or modular components" | | 4 | Montana requires **every manufacturer of modular building components** to get plan review before construction | ARM 24.301.1221(1): "Any manufacturer of modular buildings **or modular building components** shall apply to the bureau for plan review of a model or model group before construction" | | 5 | Montana requires **each manufacturer** to be approved and to be subject to 1205 Chapter 6 | ARM 24.301.1217(1): "Each manufacturer shall obtain approval from the department and be subject to Section 601 of the ICC/MBI 1205 Standard as adopted by the department" | So the question "does Montana reach a panel maker who never builds a module" has a textual answer, and the answer is yes. ARM 24.301.1221(1) does not say "units". It says "modular buildings **or modular building components**", and the adopted standard defines a panelized system as a modular component in so many words. The apparent gap in the rules is real but smaller than it looks, and it resolves cleanly: - **The state insignia is for units only.** ARM 24.301.1241(1): "All **units** manufactured or delivered prior to sale or sold or offered for sale in Montana shall bear an insignia of approval." ARM 24.301.1243(1): "The **unit** manufacturer shall apply for an insignia of approval for **each individual unit** manufactured." ARM 24.301.1205(6): "**Unit** has the same meaning as 'module'". A wall panel is not a module, so **no state insignia is issued for a wall panel, and none is needed.** - **The panel's label comes from the third-party agency instead.** ICC/MBI 1205 §701.1: "**Modular components or modules** of an approved modular building shall be marked with an insignia or other identification supplied by the third-party inspection agency that includes the name and address of the third-party inspection agency and the certification label number." That is the label that goes on the panel, and it is the agency's label, not the Bureau's. That is the whole shape of it. **Ken's plant goes into the same Montana factory-built building system once, covering both products.** The shower house comes out of that system with a Bureau insignia on it because it is a unit. The wall, roof and floor panels come out of the same system with the third-party agency's label on them, under the same approved quality manual, the same approved third-party agency contract, and their own approved model plan. One plant, one manual, one agency, two kinds of output and two kinds of label. The recommendation is section 4. The reasoning is sections 1 through 3. What has to be true in the plant is section 6. ### Sources (section 0) - ICC/MBI 1200-2021 approved ballot draft, §202 definitions: (fetched 13 Sep 2026) - ICC/MBI 1205-2021 approved ballot draft, §202 definitions and §701.1: (fetched 13 Sep 2026) - ARM 24.301.1203, incorporation by reference: (fetched 13 Sep 2026) - ARM 24.301.1205, definitions: (fetched 13 Sep 2026) - ARM 24.301.1217, manufacturer registration: (fetched 13 Sep 2026) - ARM 24.301.1221, application for model plan review: (fetched 13 Sep 2026), text confirmed against the Justia mirror listing at (search-result text, 13 Sep 2026; the Justia page itself returns 403 to an automated fetch) - ARM 24.301.1241, insignia when required: (fetched 13 Sep 2026) - ARM 24.301.1243, application for insignia: (fetched 13 Sep 2026) --- ## 1. What 1200 and 1205 actually require of a panelized-system producer This section separates what lands on a **panel** from what lands on a **module**. It matters because most of the modular industry's paperwork, and most of what a third-party agency will hand Ken as a template, is written for a volumetric box. ### 1.1 The short version: what attaches to a component that is never a module | Requirement | Applies to a panel? | Section | Why | |---|---|---|---| | Construction documents, general | Yes | 1200 §103.1, 1205 §103.1 | Written for "off-site components" | | Extra construction documents for panelized systems | **Yes, and only to panels** | 1200 §103.3, 1205 §103.3 | Section is titled for panelized systems | | Key plan with unique numbers on each delivered piece | Yes, where the AHJ requires it | 1200 §103.1(3), 1205 §103.1(3) | "multiple off-site volumetric units **and/or panels**" | | In-plant inspection | Yes | 1200 §104.2, 1205 §312.2 | 1205 §312.2 names "each modular **or panelized unit**" | | On-site inspection of connections | Yes | 1200 §104.3, 1205 §104.3, §311 | Written for "off-site components" | | Registered design professional seal on documents | Yes, where the AHJ requires it | 1205 §302.1 | Not limited to modules | | Plant QA/QC plan approved before fabrication starts | Yes | 1200 §503.1 | "Each manufacturing plant" | | Quality manual contents | Yes | 1205 Chapter 5 | "modules **and modular components**" throughout | | Serial numbering | Yes | 1205 §501.13 | "serial-number the modules **and modular components**" | | Third-party agency, initial plant certification | Yes | 1205 §401.1(12) | "not less than one module **or modular component**" | | Third-party agency, ongoing inspection frequency | Yes, **agency sets it** | 1205 §401.1(14) | Separate clause for "a modular component **or panelized system**" | | Certification label from the third-party agency | Yes | 1205 §701.1 | "**Modular components** or modules" | | Manufacturer's installation instructions | Yes | 1200 §804.1(1) and (2) | "the modules **or panelized systems**" | | Transportation permitting, route, weight, method | Yes | 1200 §702, §703 | "modules, **panelized systems** or modular components" | | Attachment tolerances | Yes, but a weak clause | 1200 §308.4 | See 1.6 below | | **Special structural requirements for modules** (stiffness, unit-to-unit interconnection, diaphragms) | **No** | 1200 §308.3, §402 | Written for modules only | | **Identification under Chapter 6 Fabrication** | **No** | 1200 §602.1 | Section is titled "Volumetric construction" | | **Stacking and on-site storage details** | **No** | 1200 §605, §705 | Written for modules | | **Installation tolerances, module to module and to foundation** | **No** | 1200 §803.1 | Written for modules | | **Modular building layout and sequencing plan, crane locations** | **No** | 1205 §302.9 | Written for modular buildings | | **Blocking plan and foundation loads imposed by modules** | **No** | 1205 §310.6, §310.7 | Written for modules | | **Manufacturer's data plate** | **No** | 1205 §701.4 | "for each dwelling unit or building" | | **State of Montana insignia** | **No** | ARM 24.301.1241, .1243, .1205(6) | "unit" means "module" | The pattern: **the process requirements reach a panel, the product-specific structural and siting requirements do not.** Ken has to run a real quality system, get a real plan approval and take a real label. He does not have to produce the module-specific engineering package (stiffness and drift limits at §402, blocking plans, data plates, stacking details) for the panel line. He does have to produce all of that for the shower house, because the shower house **is** a module. ### 1.2 Construction documents, and what has to be on them **The general requirement.** 1200 §103.1 and 1205 §103.1 are word-for-word the same and send you to IBC Section 107 or IRC R105.3 and R106, then add five items: > 1. The construction documents shall comply with the requirements of the AHJ regarding off-site components. > The AHJ responsible for approval of submittal documents shall determine where separation of off-site > components from site-built components in a set of construction documents is required. > > 2. Appropriate delineation of off-site and site-built components shall be achieved. Graphical > representations on drawing sheets shall clearly distinguish the off-site components from the site-built > components. > > 3. Where required by the AHJ for projects having multiple off-site volumetric units and/or panels, a Key > Plan for off-site components shall be provided, and all such off-site components delivered to the site shall > be identified with unique numbers. > > 4. Where required, mate lines shall be identified. > > 5. Specifications for off-site components shall be provided. Item 2 is the one that changes Ken's drawings today. The house drawings do not currently distinguish, on the sheet, what comes out of the plant from what is built on site. They have to. The panel is plant work; the slab, the anchors, the joint screws, the MEP rough-in, the cavity fill, the top track and the rake infill are site work. That line has to be **graphical**, on the drawings, not just described in text. Item 3 is the panel schedule Ken already effectively has in the model. `panels(cfg)` produces an ordered list of panels per wall; `docs/wall-contract.md` describes the frame and the per-panel opening data. That becomes the **Key Plan**: a building perimeter with every panel located and carrying a unique number, and the same number stamped on the panel in the plant. 1205 §202 defines KEY PLAN as "A building perimeter of the project, which shows the layout of the off-site volumetric units or panels with a unique identifier assigned to each of such units or panels." This is not new engineering; it is turning something the animator already knows into a drawing sheet and a stamp. **The panelized-system extras.** 1200 §103.3 and 1205 §103.3 are also identical, and this is the section the task brief pointed at. Verbatim: > **103.3 Additional requirements for construction documents for panelized systems.** The construction > documents for panel systems shall include: > > 1. Systems and components requiring special inspections. > > 2. Statement on the sequence of construction. > > 3. Details of connections for panels to the building structure. > > 4. Details of connections for panel-to-panel attachments. Four items, and Ken has none of them in a form a plan reviewer would accept: | 103.3 item | What exists today | What is missing | |---|---|---| | 1. Special inspection list | Nothing | A written list naming which systems and components in the panel get special inspection, and by whom. See section 3.2 for what belongs on it | | 2. Statement on the sequence of construction | The animation phases in `docs/wall-contract.md` and `docs/showerhouse.md`, and the build order in `wall-spec-v1.md` | A **written statement**, signed into the design basis, covering the plant sequence (bed, spacers, channel, mesh, studs, skin pour, cure, strip) and the site sequence (set, anchor, joint screws, MEP rough-in, **rough-in inspection**, cladding, cavity fill, top track). The fill pour is irreversible and buries the rough-in; the sequence statement is where that gets written down as a hold point | | 3. Panel-to-building-structure connections | `wall-spec-v1.md` §4 items 2 and 3 list them as **open**: joint screw pattern, corner strap or weld plate, slab anchor type, base detail | A stamped detail. PE work | | 4. Panel-to-panel attachments | Same open items | A stamped detail with a screw count, spacing, edge distance and a capacity. The model's placeholder is 8 × #10-16 per joint (`wall-spec-v1.md` §2, marked as an assumption) | Items 3 and 4 are **already** open items in the PE package. What 103.3 does is make them mandatory content of the construction documents rather than good practice, and it adds items 1 and 2, which nobody has started. **The 1205 Chapter 3 plan-approval package.** ARM 24.301.1221(2)(d) requires the application to include "all applicable plan approval items provided for in chapter 3 of the ICC/MBI 1205 Standard." Chapter 3 is long and mostly written for a whole building. The word that saves Ken is **"applicable"** in the Montana rule. For a wall panel model, the ones that plainly apply are: - §301.1: the manufacturer provides "plans, specifications, calculations, test results, **product evaluation reports** and critical manufacturer's instruction, and other documentation which describe in detail the product and manufacturing processes employed to produce off-site buildings or components." - §302.1 through §302.8: RDP seal, calculation cover page, name and location of manufacturer and RDP, the drawing cover sheet items (design firms, index, use and occupancy, applicable codes), the location of the insignia shown on the drawings, **§302.6** details or tables "delineating the aspects of the project that are constructed and installed in the factory and in the field, with a clear delineation of scope on the AHJ inspection responsibilities", §302.7 the revision note, §302.8 a 3" × 3" blank in the lower right of every sheet for the approval stamp. - §303.1 item 7: the structural design loads table (roof live and dead, floor live and dead, wind speed and exposure, seismic criteria and risk category, ground and roof snow, climatic design zones). ARM 24.301.1221(2)(e) separately requires wind load (Vult), construction type, seismic design category and ground snow load **on the first page**. - §310.1 through §310.5: load listings per IBC §1603, engineering analysis, design calculations, specifications of materials "to enable determination of design strengths", and details of structural elements including "framing details, spacing, size, connections and fasteners". - §311.1 and §311.2: on-site connection details "from site-built elements to modules **or panels**". Note §301.1 names **product evaluation reports** as one of the things a manufacturer may put in front of the AHJ. That is the bridge between route (a) and route (c) in section 2: an evaluation report is not an alternative to plan approval in Montana, it is evidence you can put **inside** the plan approval package. Keep that in mind when reading section 2.3. §302.8's 3" × 3" stamp space has an explicit allowance for "building component and building system plans", which is one more piece of internal evidence that the drafters expected component plans to come through this process. ### 1.3 Design responsibility and the registered design professional 1200 §301.1 sets the frame: > **301.1 Application.** Design of off-site construction shall be in accordance with the provisions of the > applicable codes and standards adopted by the authority having jurisdiction. **The requirements in this > standard shall be in addition to the requirements of the applicable codes and standards.** So the standard is additive. It does not replace the IBC or IRC, and it does not relieve the panel of anything the adopted code asks of a wall. 1200 §301.2 keeps the alternative-materials door open: > **301.2 Alternative materials, design and methods of construction and equipment.** The provisions of this > standard are not intended to prevent the use of alternate materials and methods permitted by Section 104.11 > of the IBC. That matters, because a cellular-concrete-on-cold-formed-steel cast panel is not a prescriptive assembly in any adopted Montana code. `03-codes-and-classification.md` section 1.2 already found that there is no Montana amendment addressing such a panel. The panel goes in under IBC §104.11 whichever route Ken takes. More on that in 2.2. Who signs. 1205 §302.1: "Where required by the AHJ, construction documents and other documentation shall bear the signature and seal of a Registered Design Professional. If the registered design professional is the same firm as the third-party inspection or design agency, that relationship must be disclosed to the AHJ." So the PE seals the package, and if Ken ever hires his inspection agency's engineering arm to do the design, he has to say so in writing. Two more places the standards put a named person on the hook: - 1205 §403.1: "The quality assurance administrator shall be a **Registered Design Professional** with not less than two years of actual or supervisory experience in modular or component products, and not less than two years of experience in the quality assurance function." **This is a hiring requirement and it is the single most expensive personnel line in the whole exercise.** A one-plant startup does not usually have a licensed engineer with two years of modular QA experience on staff. See section 6. - 1205 §403.2: "The quality assurance supervisor shall have not less than two years of experience as an inspector in the modular or component industry." - 1200 §504.1: the plant identifies a responsible party who "shall have the authority necessary to ensure compliance with this Standard", and quality personnel "shall demonstrate to the inspection agency that they have adequate knowledge of the product, factory operations, and the codes and standards to which the product is being manufactured." **NOT CONFIRMED:** whether the Montana Bureau enforces §403.1's "Registered Design Professional" requirement strictly for a component-only plant, or accepts a qualified non-PE administrator with PE oversight. ARM 24.301.1223 adopts Chapter 5 of 1205 for the manual; it does not separately adopt Chapter 4. But ARM 24.301.1213(1) adopts §401 of 1205 for the agency, and §403 sits in the same chapter. Ask. ### 1.4 In-plant inspection Three texts stack here. 1200 §104.2: "In-plant inspections shall verify that constructions are in compliant with the approved construction documents." (The grammar is the standard's, not mine.) 1205 §312.2, which is the one that names panels: > **312.2 In-Plant inspections.** In-plant inspections that are conducted by employees of a Third-Party > Inspection Agency shall verify that constructions are in compliance with the approved construction > documents. The Third-Party Inspection Agency shall inspect **each modular or panelized unit in a phase of > construction** or inspect modular components to verify that construction is in compliance with the approved > construction documents and the approved quality documents. 1200 §503.1, the hard gate: "Each manufacturing plant shall have an approved QA/QC plan in accordance with Chapter 5 of ICC 1205 **prior to commencing fabrication or construction activities**." And 1200 §505.2: the plant "shall notify the AHJ, or their authorized representative, **prior to the commencement of fabrication or construction projects** in accordance with the approved QA/QC plan." The frequency question, which is the one that decides whether this is affordable, is answered by 1205 §401.1(14). The standard splits it: - §401.1(13), **modules**: "the third-party agency shall inspect **each module** in a phase of construction to verify that the quality assurance process is in compliance with the initial manufacturing plant certification." - §401.1(14), **components and panels**: "the third-party agency shall **determine the frequency of inspection** of a modular component or panelized system as necessary to assure the quality assurance process is functioning in compliance with the initial manufacturing plant certification." That is a material difference and it is worth money. Every shower house gets inspected. The panel line gets inspected **at a frequency the agency sets**, which for a stable process with good records is periodic sampling, not every panel. Ken should ask each agency he quotes exactly what frequency they would set for a 34-panel house order and what that costs per visit. That number, not the state fees, is the real cost of route (a). The initial plant certification, §401.1(12), is the same for both: > The initial plant certification shall require **100 percent inspection of the aspects of construction on not > less than one module or modular component** and verify that the manufacturer has a functioning quality > assurance process. This inspection shall be made by one or more qualified engineers who have reviewed the > approved design and by a qualified inspector. If the initial module or modular component fails to conform > with the design or standard, additional modules or modular components shall be inspected until the > third-party agency is satisfied that the manufacturer complies to the approved design, the standards, and the > quality assurance manual. Note "not less than **one module or modular component**". One panel, inspected 100 percent, satisfies the letter of it for the panel line. In practice Ken should expect the agency to want to watch a full bed cycle, because a cast panel's quality is set by the pour and the cure, not by anything visible on the finished piece. And the release valve on labels, §401.1(15): "The third-party agency shall provide to the manufacturer, a written or electronic inspection report after each inspection identifying each deficiency to the standard or approved designs. **The third-party agency shall only issue labels after all deficiencies have been corrected.**" Access, 1200 §505.1: "The manufacturing facility shall not restrict access by the AHJ, or their authorized representative, at any time when manufacturing or construction activities are occurring." And ARM 24.301.1211 gives Bureau inspectors their own authority. The manual has to carry a signed permission to inspect without prior announcement (1205 §501.3). ### 1.5 Marking and identification of components This is where the "there is no insignia rule written for a panel" problem actually resolves. **What Montana's rule says.** ARM 24.301.1241(1): "All **units** manufactured or delivered prior to sale or sold or offered for sale in Montana shall bear an insignia of approval." ARM 24.301.1243(1): "The **unit** manufacturer shall apply for an insignia of approval for **each individual unit** manufactured", with the model number and serial numbers. ARM 24.301.1205(6): "Unit" has the same meaning as "module". The insignia fee at ARM 24.301.1263 is "per section". Every fee tier in ARM 24.301.1261 is worded around "units with one or two parts", "three or four parts", "five or more parts". So there is genuinely no state insignia for a wall panel, no fee line for a wall panel model, and no serial number slot on the insignia application for a wall panel. That is a real, unresolved friction in the Montana rules and Ken should say so plainly when he writes to the Bureau. It is question 2 in section 4. **What the adopted standard says.** ICC/MBI 1205 §701.1: > **701.1 Third-Party Agency Certification insignia and identification.** **Modular components or modules** of > an approved modular building shall be marked with an insignia or other identification supplied by the > third-party inspection agency that includes the name and address of the third-party inspection agency and the > certification label number. §701.2: "The insignia or identification shall be affixed so that it cannot be removed without destroying it." §701.3: "The insignia shall be under direct control of the third-party inspection agency until applied by the manufacturer to the modules or modular components that comply with this chapter. The manufacturer shall not acquire insignia from other sources. Each inspection agency shall keep a list of the serial numbers of insignia issued to each manufacturer's plant such that a copy of the record can be submitted to the administrator upon request." And the two definitions in 1205 §202 both name panels: > **DECAL.** The approved form of certification issued by the authority having jurisdiction, to be permanently > attached to the modular building, modular component **or panelized system** indicating that it has been > constructed to meet or exceed the applicable building code requirements. > > **INSIGNIA.** The approved form of certification issued by the authority having jurisdiction to the > manufacturer to be attached to the modular building, modular component **or panelized system** indicating > that it has been constructed to meet or exceed the applicable building code requirements. So the **panel takes the third-party agency's certification label under §701.1**, not a Bureau insignia. The agency controls the labels, issues them only after every deficiency is closed, and keeps the serial number record. Montana's own FBB web page says the same thing in passing when it describes what a delivered unit must carry: "All units manufactured or delivered prior to sale, sold, or offered for sale need a factory-built building insignia and, if applicable, the insignia of a reciprocal state **or the certified third party inspection agency**." **What Ken has to build into the panel for this.** A permanent, weatherproof marking on each panel carrying, at minimum: the agency label, the panel's unique key-plan number (1200 §103.1(3)), the model number, the serial number (1205 §501.13 requires a serial-numbering system for modules **and modular components**) and the cast date. Practically that means a cast-in or mechanically fastened plate on the **cavity side of the stud zone** or the top track, where it survives cladding and the cavity fill and can still be read from the top before the roof goes on, or on the exterior cladding face where the erector can read it during set. That is a product decision nobody has made and it needs to be made before the first bed is poured, because it changes the bed layout and the traveler. There is no data plate for a panel. 1205 §701.4 requires the manufacturer's data plate "for each dwelling unit or building", which is the shower house, not the panel. **Comparative evidence that component labeling is ordinary.** Washington's factory-built program defines "insignia" as "A label that we attach to a structure to verify that a factory-built house or commercial structure meets the requirements of this chapter. It could also be a stamp or label attached to a component..." (WAC 296-150F-0020, fetched 13 Sep 2026). Washington labels components as a matter of routine. Montana has not written that sentence, but it has adopted a standard that says the same thing at §701.1. ### 1.6 Installation instructions and tolerances The task brief pointed at 1200 §803.1 for tolerances. **That citation is right for the shower house and wrong for the panel**, and the difference is worth knowing before Ken's PE quotes the work. **§803.1 is written for modules:** > **803.1 Installation Tolerances.** The registered design professional shall detail in the construction > documents the required construction tolerances for fitting **each module to each module and to the > foundation**. Terms shall be as defined in ISO 6707-1:2020. That is the shower house: module to foundation, with ISO 6707-1:2020 vocabulary. **The panelized tolerance clause is §308.4, and it is thin:** > **308.4 Tolerances for panelized system construction.** Tolerances for the attachment of panelized systems to > other systems and interfacing construction shall be **as established by the manufacturer of the attachment > device**. Read that carefully. For a panel, the standard hands the tolerance question to **the maker of the attachment device**, meaning the screw manufacturer's published edge distance, spacing and installation tolerances. That is much less than Ken needs. A 4-foot cast panel standing on a slab has cumulative width tolerance across ten panels, out-of-plumb, bow, twist and a joint gap, and no screw manufacturer's data sheet answers any of that. So: **§308.4 does not get Ken out of setting panel tolerances, it just means no adopted standard sets them for him.** The PE has to set them, and `04-quality-manual-requirements.md` section 10 item 6 already flags panel dimensional tolerances as having no published source. This is the same gap seen from the other side. What the manual needs is an acceptance band (width, height, thickness, squareness, bow, twist, face flatness, opening location) and what the erection instructions need is a cumulative-run tolerance and a shim or grout allowance at the base. **Installation instructions do reach panels, clearly.** 1200 §801.1: "The manufacturer shall provide instructions that include installation procedures and layout information." And §804.1, which names panelized systems twice: > **804.1 Manufacturer instructions.** The manufacturer shall provide instructions that describe the details > for: > > 1. Connecting the modules **or panelized systems** to provide the required structural strength and rigidity. > > 2. Maintaining the integrity of the air barrier system, vapor barrier, insulation, sheathing membrane, > cladding, roofing and flashing at the joints between each module **or panelized system**. > > 3. Connecting ducting, piping and wiring, and maintaining the integrity of sealing and insulation. > > 4. Maintaining the integrity of fire separations and providing fire blocking between modules where required. > > 5. Foundation loads, anchorage details and required capacity of anchorage devices. > > 6. Maximum foundation support, spacings, and any additional information necessary for the proper support of > the modular building. > > 7. Information on the connection of services. > > 8. Installation of all other items to be installed or completed on site. Item 1 is the screwed edge-stud joint. Item 2 is the air barrier at the panel joint, which matters twice over because ARM 24.301.161 as amended requires the house to test at **4 ACH50** (`03-codes-and-classification.md` section 1.2), and the panel joint is the leak path nobody has detailed. Item 5 is the slab anchor. Item 8 covers the cavity fill, which is site work on the house. These eight items are the **erection manual**, and Ken does not have one. See section 7. ### 1.7 The third-party plan review and inspection framework in 1205 Montana plugs into 1205 at three points and it is worth seeing them together. | Montana rule | What it adopts | Effect | |---|---|---| | ARM 24.301.1213(1) | "Third-party inspection agencies shall meet the requirements of **Section 401** of the ICC/MBI 1205 Standard as adopted by the department." | The 19-item agency approval list becomes Montana law | | ARM 24.301.1217(1) | "Each manufacturer shall obtain approval from the department and be subject to **Section 601** of the ICC/MBI 1205 Standard as adopted by the department." | Manufacturer registration duties become Montana law | | ARM 24.301.1221(2)(d) | "all applicable plan approval items provided for in **chapter 3** of the ICC/MBI 1205 Standard" | Chapter 3 becomes the submittal checklist | | ARM 24.301.1223(2) | "all applicable items as listed in **chapter 5** of the ICC/MBI 1205 Standard" | Chapter 5 becomes the manual's table of contents | **1205 §601, the manufacturer's own duties**, which ARM 24.301.1217(1) pulls in directly: - §601.1: "Manufacturers shall not engage in business activity relating to the construction of modular buildings without being approved by the Authority Having Jurisdiction." - §601.2(2): "**Each separate manufacturing facility shall be approved.** A manufacturing facility is separate if it is not on property that is contiguous to a registered manufacturing facility." One plant, one approval. A second yard down the road is a second approval. - §601.2(3): written notice to the AHJ on a name change, an address change, **a change of 25 percent or more of ownership in any 12-month period**, a new facility, or a change of principal officers. A change of ownership requires a new registration unless the new owners accept responsibility for units built under the old owners. Worth knowing before Ken takes an investor. - §601.4: "The AHJ shall maintain a list of approved third-party inspection agencies. **Each manufacturer shall contract with one or more inspection agencies** for evaluation, monitoring and inspection services. The contract shall delineate the services to be provided by the inspection agency. **The inspection agency shall notify the AHJ not more than 30 days of signing a new contract or terminating an existing contract** with any manufacturer." Note the last clause: if Ken fires his agency, the Bureau hears about it within 30 days. - §601.5: AHJ right of entry to the plant and to building sites. **1205 §401.1, the agency's 19 commitments.** `02-approval-process.md` section 4 already lists the duties that shape the plant routine and I am not repeating them. Three that bear specifically on a panel line: - §401.1(6) accreditation: "A copy of the accreditation certificate, issued by an **ISO/IEC 17011-compliant accreditation body**, that establishes the ability to provide services in accordance with the **ISO/IEC 17065** standard for product evaluation or the **ISO/IEC 17020** standard for inspection service, as appropriate." This is the exact text, and it answers an open item in `02-approval-process.md` section 4: the two ISO standards named are 17065 for product evaluation and 17020 for inspection. Montana's own paper form softens this to "provide it or tick the box saying you are not accredited." - §401.1(10) independence: no actual or potential conflict of interest, not affiliated with, influenced by or controlled by any client manufacturer. - §401.1(11): the agency reviews each design, writes deficiencies item by item with citations, verifies correction, and **stamps or signs each page**, sending a copy to the AHJ and to the manufacturer. So on route (a) Ken gets two reviews of the panel drawings: the agency's and the Bureau's. **1205 §402** puts the state or accreditation body over the agency, with unannounced monitoring and a **20-day plan of corrective action** requirement when a deficiency is found. **Remote virtual inspection** is in the standard at 1205 §301.2 and §312.2.1: the AHJ has the option to conduct inspections by live video, with the permit holder operating the camera at the inspector's direction. For a Montana plant being inspected by an agency in Indiana or Utah, RVI is the difference between a $2,000 travel day and a scheduled video call. **NOT CONFIRMED** whether the Montana Bureau permits RVI for in-plant factory-built building inspections in practice, or whether any of the 17 listed agencies will use it here. It is worth asking every agency Ken quotes, because it may be the single biggest lever on ongoing cost. ### Sources (section 1) - ICC/MBI 1200-2021 approved ballot draft, §§101-104, 202, 301, 308, 501-506, 601-605, 701-705, 801-804: (fetched 13 Sep 2026) - ICC/MBI 1205-2021 approved ballot draft, §§101-104, 202, 301-312, 401-403, 501-503, 601, 701: (fetched 13 Sep 2026) - ARM 24.301.1213, third-party agency approval: (fetched 13 Sep 2026) - ARM 24.301.1217, manufacturer registration: (fetched 13 Sep 2026) - ARM 24.301.1221, model plan review: (fetched 13 Sep 2026) - ARM 24.301.1223, QA manual: (fetched 13 Sep 2026) - ARM 24.301.1241 / .1243 / .1261 / .1263, insignia and fees: , , , (all fetched 13 Sep 2026) - Factory-Built Buildings Permits, Montana DLI, page text including the third-party insignia sentence, page dated 1/28/26: (fetched 13 Sep 2026) - WAC 296-150F-0020, Washington definitions including "insignia" attached to a component: (fetched 13 Sep 2026) - ICC/MBI 1205 explainer (background only, not normative): (fetched 13 Sep 2026) --- ## 2. The three routes, compared ### 2.1 Route A: put the panels into the Montana factory-built building system **What it is.** Ken registers as a manufacturer, gets the QA manual approved, gets a model plan approved for the panel line, contracts an approved third-party agency, takes the initial plant certification, and ships panels carrying the agency's certification label. The shower house goes through the same machinery and comes out with a Bureau insignia as well. **The legal basis, restated.** ARM 24.301.1221(1) requires plan review from "any manufacturer of modular buildings **or modular building components**". A panelized system is a modular component (1205 §202). ARM 24.301.1217(1) requires every manufacturer to be approved, and "manufacturer" in the adopted standard expressly includes a maker of panelized systems. This is not a workaround. It is the rule read straight. **The process, end to end.** The sequence is exactly the one in `02-approval-process.md` section 9, with three differences for a panel model: 1. There is no insignia application step (step 12 of that file's table) and no $40-per-section insignia fee for a panel. The agency's label replaces it. 2. The ongoing inspection frequency is set by the agency (1205 §401.1(14)), not fixed at every unit. 3. The construction documents carry the four extra §103.3 items. **What it costs.** | Item | Cost | Source | |---|---|---| | QA manual review | $20 once, $20 per revision | ARM 24.301.1261 | | Third-party agency application review, if the agency is not already listed | $20 | ARM 24.301.1261 | | Plan review, panel model, structural | **Unclear.** Every tier is worded around "units with one or two parts" etc. A panel model has no tier | ARM 24.301.1261 | | Plan renewal, annual | $100 per model | ARM 24.301.1261 | | Third-party agency contract | **Not published and not controlled by the state.** The real number | ARM has no fee for this | | Quality assurance administrator, a Registered Design Professional with 2 years modular QA experience | A salary line, or a contracted part-time role | 1205 §403.1 | | PE work: special inspection list, sequence statement, joint and anchor details, tolerances, erection manual | Not estimated here | 1200 §103.3, §308.4, §804.1 | The state fees are trivial. The two real costs are the third-party agency contract and the §403.1 quality assurance administrator. **Neither is published anywhere.** Ken has to get three quotes. **What Ken gives up.** Freedom to change the panel without telling anyone. ARM 24.301.1227 makes any change to construction an application for revision with a $125 structural resubmission fee. ARM 24.301.1233 revokes the plan review when the department adopts a different code version, with only 90 days to use existing approvals. And the Bureau can revoke plan review if it finds Ken building to something other than the reviewed plan. For a product still in development, that is the honest cost: **route A freezes the design.** Every stud gauge change, every screw pattern change, every mix change that alters a stated strength is a revision. Ken should not enter plan review until the PE package is closed out, or he will pay for the same review three times. **What Ken gets.** MCA 50-60-402(3) and ARM 24.301.1245(1): a unit bearing the insignia is "acceptable as meeting the requirements of Title 50, chapter 60, MCA, throughout the state of Montana without further inspection or fees except for zoning, utility connections, and foundation permits as required by the authority having jurisdiction." For the shower house, that is the whole business case: build it once, sell it anywhere in Montana, and no local inspector opens it up. For the **panel**, the acceptance sentence is written around "units", so it does not literally cover a labelled panel. What the panel gets instead is softer but still valuable: an approved model plan on file with the state, an agency label with a traceable serial number, and a plan reviewer at the state who has already looked at the assembly. A local building official confronted with a cast panel he has never seen has something official to read. That is worth a great deal in practice and it is worth nothing in law. **NOT CONFIRMED** whether the Bureau would extend ARM 24.301.1245(1) acceptance to a labelled panelized system; question 3 in section 4. ### 2.2 Route B: treat the panels as ordinary building materials, with the engineer's stamp and site special inspection **What it is.** Ken sells panels as a manufactured building product. No manufacturer registration, no QA manual at the state, no third-party agency. Compliance rides on the project engineer's stamp, IBC §104.11 approval of an alternative material by the building official at each job, and special inspection under IBC Chapter 17. **Whether it is legal.** For the **house**, there is an argument. The finished house is site-built (`03-codes-and-classification.md` section 3.2 walks it): no module ever leaves the plant, and the statutory factory-built building definition at MCA 50-60-101(9)(a) fails on two legs because a panel is not a structure and carries no service connections. If the house is not a factory-built building, MCA 50-60-402(1) does not bite, because that subsection reaches "any new factory-built building unless the factory-built building **and its components**, systems, and appliances have been constructed and assembled in accordance with the standards defined in this part". The hook is on components **of a factory-built building**, not on a panel sold as a material. The argument fails at ARM 24.301.1221(1), which does not condition plan review on the panel ending up in a factory-built building. It says "any manufacturer of modular buildings or modular building components shall apply". Ken would be arguing that a rule written to reach component manufacturers does not reach him. That is a losing position to build a plant on. **What special inspection of a panelized system at the site actually looks like.** This is the part of route B that does not work, and it is worth spelling out because it is the reason the whole off-site framework exists. IBC §1704.2 (2021, as adopted in Montana at ARM 24.301.131; **ARM 24.301.146 contains no modification to Chapter 17**, checked against the list of 51 modifications): "The owner or the owner's authorized agent, other than the contractor, shall employ one or more approved agencies to provide special inspections and tests during construction." Then IBC §1704.2.5: "Where fabrication of structural, load-bearing or lateral load-resisting members or assemblies is being conducted on the premises of a fabricator's shop, **special inspections of the fabricated items shall be performed during fabrication**, except where the fabricator has been approved to perform work without special inspections in accordance with Section 1704.2.5.1." Read those two together and route B collapses into route A with worse economics: - The cast panel is a structural, load-bearing assembly fabricated in a fabricator's shop. §1704.2.5 puts a special inspector **in Ken's plant during fabrication**. - The inspector is employed by **the project owner**, not by Ken, and a different one can show up for every job. - There is no statewide acceptance at the end of it. Each project's building official makes his own §104.11 call on the same panel. **The buried steel cannot be signed off after the fact.** That is the point of the PANELIZED SYSTEM definition: "constructed at a location other than the building site in a manner that prevents the construction from being inspected at the building site without disassembly, damage or destruction thereof." Once the skin pour cures, the stud-to-track screws, the channel row placement, the mesh position and the skin depth over the mesh are gone. A site special inspector arriving after delivery has three options: accept the fabricator's records, break a panel, or refuse. IBC §110.3 inspection practice generally does not let an inspector approve concealed work he never saw, and IBC §1704.2.4 requires the special inspector to report discrepancies and to furnish a final report stating whether the work was in conformance; an inspector who never saw the work cannot write that report honestly. **NOT CONFIRMED** verbatim: I did not read §1704.2.4 or §110.3 word for word in the Montana viewer; the characterisation is from the structure of Chapter 17 and standard practice, not from a quoted line. **The one honest version of route B: approved fabricator status.** IBC §1704.2.5.1 lets a fabricator be approved to work without per-project special inspections, on review of "the fabricator's written procedural and quality control manuals" and "periodic auditing of fabrication practices by an approved agency", with a **certificate of compliance** submitted at completion of fabrication stating the work was performed in accordance with the approved construction documents. Look at what that requires: a written quality control manual, an approved auditing agency, periodic plant audits, and a certificate per job. **That is the same quality system as route A, built for one building official at a time instead of once for the state.** It gets Ken a manual and an agency and gives him no statewide acceptance, no state plan approval, and no label. It is strictly worse than route A unless the Bureau tells Ken it will not accept him into the factory-built building program at all, in which case §1704.2.5.1 is the fallback and Ken should say so in his letter. **Who would actually approve the fabricator?** §1704.2.5.1 says "approved" without saying by whom; in practice it is the building official of the jurisdiction, or a listing from an accredited agency (IAS accredits fabricator inspection programs; see 2.3). In Montana, outside a certified city that means the State Building Codes Bureau, which is the same office as route A. Inside Bozeman or Missoula it means that city. **A fabricator approval from Bozeman does not travel to Billings.** That is the fatal flaw. **Verdict on route B.** It saves nothing, it does not avoid an inspector in the plant, it produces no statewide acceptance, and it puts Ken in front of a different building official on every job with the same argument to make each time. Use it only as a fallback if the Bureau refuses route A. ### 2.3 Route C: a product evaluation report **What it is.** An accredited evaluation body examines the panel against a published acceptance criteria document and issues a numbered report saying the panel complies with named sections of the IBC and IRC. Any building official can then approve the panel under IBC §104.11.1, which says supporting data for materials not specifically provided for in the code "shall consist of valid research reports from approved sources." **Which acceptance criteria could apply.** There is no ICC-ES criteria document written for a cellular-concrete skin cast onto cold-formed steel studs. There are four that a pre-application call would put on the table, and all four are real, verified titles: | AC | Title | Status | Why it is in the conversation | |---|---|---|---| | **AC15** | Concrete Floor, Roof and Wall Systems and Concrete Masonry Wall Systems | Approved Feb 2010, editorially revised Dec 2024 | **Closest precedent in use.** ESR-1662 (Superior Walls Xi, a precast concrete wall panel with integral concrete studs) lists AC15 as its evaluation basis | | **AC04** | Sandwich Panels | Approved June 2019, editorially revised Aug 2024 | The 2009 edition's §1.0 called itself "general in nature and applicable to all sandwich panels except where other current ICC-ES acceptance criteria are applicable". **NOT CONFIRMED** that the June 2019 text keeps that scope sentence; the current edition is paywalled | | **AC272** | Cellular Concrete | Approved May 2015 | **Probably does not help.** ESR-2748 recognises cellular concrete "used in roof decks over concrete or steel substrates or in floor underlayment over wood-based sheathing", not as a structural skin. **NOT CONFIRMED** whether AC272's own scope forbids structural use; the criteria text was not read | | **AC46** / **AC322** / **AC553** / **AC543** | Cold-formed Steel Framing Members / Prefabricated Cold-formed Steel Lateral-force-resisting Vertical Assemblies / Establishing Equivalency of Prefabricated Wall Panels to Prescribed Braced Wall Panels Under the IRC for One-story Residential Dwellings / Structural Performance of Modular Components for Off-site Construction | Various, all current | Each covers a slice. AC553 is interesting for the house because it is about equivalency to IRC braced wall panels, which is exactly the argument Ken's house has to win | **The most useful finding is that a new criteria document may not be needed at all.** ESR-1638 (Saebi Alternative Building System, a welded-wire-mesh and foam-core structural wall, floor and roof panel with cementitious skins, reissued July 2026) lists under EVIDENCE SUBMITTED only ASTM test data (C109, C947, C948, E72, E108, E331, NFPA 286 and others) plus "Engineering calculations of composite structural system". **No acceptance criteria are cited at all.** ICC-ES issued a report on a composite panel system on test data and calculations. That is the first question for a pre-application call: does this panel go on AC15, on AC04, or on a data-and-calculations package like ESR-1638. The nearest published system to Ken's exact geometry is **Metal Stud Crete** (shear connectors on light-gauge steel framing embedded in wet concrete to form a composite panel), ESR-2511. I could not retrieve ESR-2511, so the criteria behind it are **NOT CONFIRMED**. **What developing a new criteria document costs, if one is needed.** From the ICC-ES Rules of Procedure for the Evaluation Committee, revised June 2025: - §5.2.1: "Proposed acceptance criteria shall be developed by the ICC-ES staff and discussed in open session with the Evaluation Committee during a scheduled meeting." Ken cannot write his own. - §5.1: consideration of criteria "must be in conjunction with a current and valid application for an ICC-ES evaluation report." You pay for the report application first. - §2.2: every committee member is a representative of a code-enforcement body. - §3.2: three to six meetings per year. §5.2.2: proposals posted at least 30 days before. - §5.3: the outcomes are Approval, Approval with Revisions, Disapproval, or Further Study. ICC-ES's published deadline table shows roughly **112 days from proposal deadline to hearing** per cycle (3 Nov 2026 hearing, proposals due 14 Jul 2026; 17 Feb 2027, due 27 Oct 2026; 22 Jun 2027, due 2 Mar 2027; 2 Nov 2027, due 14 Jul 2027). The staff letter for AC509 (3D Automated Construction Technology for 3D Concrete Walls) records first approval in June 2019 followed by revision rounds in December 2020, September 2021, December 2021, October 2022 and August 2023: **about four years of churn for a genuinely new construction technology.** **The quality system a report obliges.** This is the part Ken needs to compare against route A, and it is almost the same burden. From the ICC-ES Rules of Procedure for Evaluation Reports, revised 13 Oct 2025: - §4.1: engineering documents sealed by a registered design professional. - §4.2: testing at an **ISO/IEC 17025** laboratory accredited by an ILAC MRA signatory, at the applicant's expense. - §4.3: applications for prefabricated building components must include plans differentiating **field-installed from factory-installed** items. (That is the same delineation 1200 §103.1(2) and 1205 §302.6 require. Do it once, use it in both places.) - §4.4: "Applicants shall submit detailed quality documentation, meeting ICC-ES requirements, for the product or building system and the manufacturer's plant." The governing document is **AC10, Quality Documentation**. - §4.5: any third-party agency doing inspections for ICC-ES must hold a contract with ICC-ES and be accredited to **ISO/IEC 17020**, costs borne by the applicant. - §4.6 and §9.0: **a qualifying plant inspection is a precondition to the report issuing**, and the same applies when a new plant is added. - §9.0: "either ongoing follow-up or annual inspections are required", plus reimbursement of ICC-ES travel and time. - §11.2: failing to maintain the quality control program, or denying access to the plant, is grounds for suspension or revocation without notice or hearing. So route C also means a written quality manual, an accredited agency, an initial plant inspection and periodic audits. **It is the same plant discipline as route A with a different reader.** **Cost and time, honestly.** ICC-ES does not publish fees. §6.0 of the Rules of Procedure for Evaluation Reports is literally headed "FEES (Contact ICC-ES staff for fee information)". The only quantified public figure found anywhere is trade press: Frame Building News (June 2021) quoting the president of Perma-Column that getting an ICC-ES report "was two years of hard work requiring significant investments in time, money, people, and resources", and stating that manufacturers "can spend tens of thousands of dollars on the testing and certification process to get a single product certified". **That is trade press, not ICC-ES, and no more precise number is defensible.** Cost buckets that are confirmed to exist but unpriced: application fee, per-page and per-item and per-listee and per-code fees, annual renewal, revision fees, the qualifying plant inspection, ongoing follow-up inspections, ICC-ES travel, the ISO 17025 test programme, and a surcharge on applications left open more than a year. **Working estimate, stated as inference and not as fact:** if AC15 or AC04 or an ESR-1638-style data package is accepted as the basis, a conventional evaluation report is plausibly **9 to 18 months**, dominated by lab testing rather than committee calendars. If ICC-ES insists on new criteria, **add one to three hearing cycles**, which on the AC509 evidence is another year or two. **Alternatives to ICC-ES.** All of these issue code evaluation reports: | Body | Report | Published timeline | Note | |---|---|---|---| | **IAPMO UES** | Evaluation Report (ER) | **Yes.** Targets under 12 weeks, some in 40 days, "most take approximately three months" | The only body publishing a timeline, and it openly writes its own Evaluation Criteria for products the codes do not address, approved by public review plus a vote of code officials. Says it does not charge further-study fees | | **Intertek** | Code Compliance Research Report (CCRR) | No | States it is accredited to ISO/IEC 17065 by IAS | | **DrJ Certification** | Technical Evaluation Report (TER) | No | ANAB ISO/IEC 17065 accredited certification body | | **UL Solutions** | Evaluation Report | No | States it follows ICC-ES **AC10** requirements for inspections and quality audits | | **PFS-TECO** (NFPA Global Solutions) | Building Product Evaluation Report (BPER) | No | Issues BPERs evaluated **against ICC-ES acceptance criteria**. Also on Montana's approved third-party FBB agency list | Note the last column of that table: several of these bodies evaluate against ICC-ES criteria anyway. Changing evaluation bodies escapes the ICC-ES committee calendar, not the criteria problem. **IAS accreditation, for completeness.** This closes an open item in `02-approval-process.md` section 4, which could not confirm which IAS criteria cover modular or off-site inspection agencies. The answer is that **IAS does not appear to publish a numbered AC dedicated to modular or off-site inspection agencies.** What it has instead: | IAS doc | Title | Edition | |---|---|---| | **AC98** | Accreditation Criteria for Inspection Agencies (the ISO/IEC 17020 programme) | Landing page implies effective 1 Feb 2022; **NOT CONFIRMED**, the PDF would not open | | **AC291** | Accreditation Criteria for Special Inspection Agencies (doc IAS/SIA/011) | 11 Jun 2025, effective 1 Aug 2025 | | **AC157** | Accreditation Criteria for Fabricator Inspection Programs for Reinforced and Precast/Prestressed Concrete (doc IAS/FA/011) | April 2017, effective 1 Jun 2017. **A newer edition may exist; NOT CONFIRMED** | | **AC172** | Accreditation Criteria for Fabricator Inspection Programs for Structural Steel | not read | | **AC473** | Accreditation Criteria for Inspection Programs for Manufacturers of Cold-Formed Steel Structural and Nonstructural Components Not Requiring Welding | recognised under IBC §1704.2.5.1 | | **AC402** | Accreditation Criteria for Third-Party Permitting, Plan Review and Inspection Service Providers | not read | For off-site work IAS accredits against **ICC/MBI 1200 and 1205 themselves** rather than against a numbered AC. That is from search snippets of the IAS portal, which returned HTTP 500 to a direct fetch, so it is **NOT CONFIRMED**. `04-quality-manual-requirements.md` section 2.4 already uses AC157 as a model for what an inspector looks for in a concrete plant; that use stands, and the AC157 edition date above should be checked before it is cited in a submittal. **AC157 §1.1 is explicit that "These criteria do not cover the fabricated products or the design or performance characteristics of the products"**, so it is a plant-accreditation document, not a product approval. **Montana's own version of route C, which is the surprise.** Montana has no Florida-style statewide product approval programme, but it does run a list called **Approved Alternative Methods and Materials**, citing MCA 50-60-201 as its authority. The statutory hook is MCA 50-60-103(4): the department may "recommend tests or require the testing and approval of materials, devices, and methods of construction to ascertain their acceptability under the requirements of the state building code and issue certification of the acceptability." The list is tiny. It has two entries: 1. **3-D printed buildings utilizing hemp**, approved "as an alternate means of compliance for all types of construction", allowed anywhere CMU block construction is used. 2. **Jones Stephens Corporation PEX-AL-PEX piping and fitting system**, approved for gas applications under the 2018 IFGC §105.2. Entry 1 is directly on point. **Montana has already issued a named, statewide approval for a novel cementitious wall system, without an ICC-ES report.** No application form, fee schedule or timeline is published; the contact is the same Bureau at (406) 841-2056 and buildingcodes@mt.gov. **NOT CONFIRMED:** how a product gets on this list, what is submitted, who decides, whether there is a fee, and whether the approval binds certified local programs or only the state programme. That is question 6 in section 4, and it is a cheap question to ask. **Verdict on route C.** An ICC-ES or UES report is the right tool if Ken wants to sell panels **outside** Montana, because a research report travels and a Montana approval does not. It is the wrong tool as the primary Montana compliance path, for three reasons: it does not satisfy ARM 24.301.1221(1), which requires plan review from component manufacturers regardless of what reports they hold; it obliges essentially the same plant quality system as route A; and IBC §104.11.1 makes a research report **supporting data for the building official's approval**, not an approval in itself. Every official still gets to say yes or no. The **Montana alternative-methods listing** is a different animal and is worth pursuing as a cheap supplement, because it is a statewide yes from the same office that runs the factory-built building programme. And remember 1205 §301.1: a product evaluation report is one of the things the manufacturer submits **as part of** the plan approval package. The routes are not mutually exclusive. A report makes route A easier; it does not replace it. ### 2.4 The prior question: is Ken in the factory-built building system at all? Route A assumes Ken is a Montana factory-built building manufacturer. For the **panel line** that follows from ARM 24.301.1221(1) regardless of anything else. For the **shower house** it turns on whether the unit meets the statutory factory-built building definition, and that is the biggest open question in the whole file (`03-codes-and-classification.md` section 10 item 1). It matters here because the economics of route A rest on one quality system covering both products. **The definition has four legs, joined by "and".** MCA 50-60-101(9) and ARM 24.301.1205(4): "a factory assembled structure or structures equipped with the necessary service connections, but not made so as to be readily movable as a unit or units and designed to be used with a permanent foundation." | Leg | Shower house as designed today | Verdict | |---|---|---| | 1. Factory assembled structure | Built complete in the plant, one piece | Meets | | 2. Equipped with the necessary service connections | Plumbing, DWV, shut-off, backflow preventer, 100 A panel, power inlet, all plant-installed | Meets | | 3. **Not made so as to be readily movable as a unit** | Welded HSS skid, fork pockets, four 10,000 lb corner lifting lugs, tie-down rings, marketed as movable | **Fails on the plain words** | | 4. **Designed to be used with a permanent foundation** | "gravel pad, blocks, or piers", no bearing diagram, no anchorage capacity | **Fails as designed** | **Leg 4 is fixable, and fixing it fixes a second problem at the same time.** DPHHS requires a campground service building to be "of permanent construction" (ARM 37.111.1216(1)(a)). That rule uses an **undefined** term. The defined term in the same subchapter is different: ARM 37.111.1201 defines "**permanent foundation**" as "concrete, concrete block, or wood pier, resting on embedded concrete or concrete block footings. The term does not include mud sill, pier and post, wood blocks, concrete block, or other types of temporary support, resting on the ground", and "**permanent structure**" as a structure attached to a permanent foundation. "Permanent construction" is neither of those and is not defined anywhere I could find. A sibling document in this repo treats "permanent construction" and "permanent foundation" as the same thing. **They are not, and that distinction should be preserved**: 37.111.1216(1)(a) uses a term the rule never defines, so a sanitarian's reading of it is a judgment call, not a lookup. That said, designing the unit to sit on **embedded concrete or concrete-block piers** does three things at once: 1. It satisfies leg 4 of the factory-built building definition on its face, because the unit is then "designed to be used with a permanent foundation" in the ordinary sense and in the sense of ICC/MBI 1200's PERMANENT FOUNDATION SYSTEM definition ("anchorage of the building to the foundation is provided to resist the uplift and sliding forces that result from the application of the prescribed loads"), provided the PE stamps the anchorage. 2. It lands squarely inside the DPHHS **defined** term "permanent foundation" at ARM 37.111.1201, which is the strongest available evidence for a sanitarian reading the **undefined** term "permanent construction" at 37.111.1216(1)(a). 3. It leaves the skid where it belongs: as the transport, lifting and handling frame, not as the foundation. That is a much better story than arguing whether a skid on blocks counts as a foundation. **Does leg 3 defeat it anyway?** This is the question that has to be answered honestly, and the answer is: it depends on what Ken says in the design documents, and it is not free. The federal analogue is instructive. HUD's modular exclusion at 24 CFR 3282.12 lets a manufacturer certify a structure out of the manufactured-housing standards where, among other things, "the structure is designed only for erection or installation on a site-built permanent foundation", "the structure is **not designed to be moved once erected or installed** on a site-built permanent foundation", and the towing hitch or running gear "are **removable and designed to be removed** prior to erection". Three features of that test are worth copying: - The federal test is about **design intent expressed in the documents**, not about whether the object is physically liftable. Every modular box ever built is physically liftable; a crane does not decide the classification. - The federal test requires the transport hardware to be **removable and designed to be removed**. Ken's skid is not removable; it is the floor framing. - The federal test asks whether the structure is designed to be moved **once erected**, which is a weaker requirement than Montana's "not made so as to be readily movable". Montana's leg 3 is about **how the thing is made**: "not **made so as** to be readily movable as a unit or units." A unit built on a welded skid with fork pockets and four rated corner lifting lugs is made so as to be readily movable. That is not a paperwork problem; it is a fact about the product, and it is the product's main selling point (`docs/showerhouse.md`: "Steel tubing base under it so it can be moved or delivered into place"). So the two legs do **not** simply work together. Leg 4 is a design decision Ken can make. Leg 3 is a design decision Ken has already made in the other direction, and the Bureau is entitled to read it that way. **Three things push back the other way, and together they are strong enough to make this the position to argue:** 1. **The Bureau's own published definition drops leg 3.** The DLI FBB page's headline definition reads: "Factory-Built Building (FBB) is a factory assembled structure(s) equipped with the necessary service connections and designed to be used with a permanent foundation." The "not made so as to be readily movable" clause is simply absent. Further down the same page the full statutory definition appears with the clause restored. The page contradicts itself. That is not authority, and Ken should not rely on it. It is evidence about how the program thinks, and what it suggests is that the program's working test is **the permanent foundation leg**. 2. **The Bureau already labels this family of product.** On the Approved Factory Built Building Manufacturers list dated 9/02/2026 are **Public Restroom Company** (Reno, NV), **CXT Inc** (Spokane Valley, WA), **Crest Precast Inc** (La Crescent, MN), **Mountain West** (mwprecast.com), and **Big Sky Dog Wash** (Billings, MT). CXT and Public Restroom Company both build precast concrete restroom and shower buildings that arrive complete on a truck and are set by crane on a prepared pad. If those are in the program, a cast-concrete shower house belongs in the program. 3. **The alternative is worse for everyone, including the Bureau.** If the shower house is not a factory-built building, there is no plan review and no in-plant inspection of the plumbing and wiring buried in a cast floor panel, and a local inspector is asked to approve work he cannot see. A regulator asked to choose between "insignia" and "nobody inspects the concealed work" picks insignia. **What Ken should do about it.** Design and document for a permanent pier foundation, and stop claiming relocatability in the code documents. Specifically: - The PE produces the bearing and anchorage sheet (`03-codes-and-classification.md` gap 3): bearing diagram, maximum pier spacing, minimum bearing pressure, anchorage device and capacity, for a stated wind and snow envelope. 1200 §804.1(5) and (6) and 1205 §310.6 and §310.7 are the checklists. - The design basis says the skid is the transport, lifting and handling frame and the **floor structure**, and that the unit is designed to be installed on a permanent foundation system as defined in ICC/MBI 1200. - The installation instructions say the unit is set on that foundation and anchored, full stop. They do not describe seasonal relocation. - **The sales material can still say the unit is delivered complete and can be relocated**, because once a Montana insignia is attached it belongs to that unit and travels with it (ARM 24.301.1243(2): the manufacturer attaches it "to each unit"; ARM 24.301.1247 governs lost, damaged and void insignia, not relocation). Moving an insignia'd unit later is a siting question, meaning zoning, a foundation permit and utility connections at the new site, exactly the three things ARM 24.301.1245(1) carves out. **NOT CONFIRMED**: I found no Montana rule that voids an insignia on relocation, and no rule that expressly blesses it. Ask the Bureau, because the answer is a sales fact. **The fallback if the Bureau says no.** If the Bureau rules the shower house out of the factory-built building program on leg 3, the shower house becomes an ordinary IBC building requiring a site permit at every destination, and its concealed plant-installed plumbing and wiring become the buyer's problem. In that case the panel line still goes through route A on its own (ARM 24.301.1221(1) does not depend on the shower house), and the shower house is sold with the panel model's approval plus a per-site permit. That is a materially worse product and Ken should know the risk before he tools up. **One sales fact worth carrying out of the DPHHS rules while we are here.** ARM 37.111.1216(1)(g) and Table I set the fixture count for a campground service building by the number of dependent unit sites: | Dependent unit sites | Toilets | Handwashing sinks | |---|---|---| | 1 to 15 | 2 | 2 | | 16 to 30 | 4 | 4 | | 31 to 45 | 6 | 6 | | 46 to 60 | 8 | 8 | | 61 to 80 | 10 | 10 | | 81 to 100 | 12 | 12 | | over 100 | 2 more for each additional 75 sites | | A 2-bath unit serves a campground of **15 dependent sites**. A 50-site campground needs **8 toilets**, which is **four units**. That belongs in the sales material and the configurator, not buried in a code file. (This repeats `03-codes-and-classification.md` section 4.3 deliberately, because it is the number a salesperson needs and it is the number that sizes the order.) ### 2.5 Side by side | | A: factory-built building system | B: building material + site special inspection | C: product evaluation report | |---|---|---|---| | Legal basis in Montana | ARM 24.301.1217, .1221(1), .1223, .1213 | IBC §104.11 + Chapter 17, or §1704.2.5.1 approved fabricator | IBC §104.11.1 research reports; MCA 50-60-201 alternative methods list | | Who reviews the design | Bureau **and** the third-party agency (1205 §401.1(11)) | Each project's building official, every time | The evaluation agency, once | | Who inspects the plant | Approved third-party agency, frequency set by the agency for panels | A special inspector employed by each project owner, or an auditing agency under §1704.2.5.1 | The report's listed inspection agency, periodic audits | | What the panel carries | Third-party agency certification label, 1205 §701.1 | Nothing | The evaluation agency's listing mark | | Statewide acceptance | Yes for the shower house (ARM 24.301.1245(1)); **unconfirmed** for the panel | No | Persuasive, not binding; each official still approves under §104.11 | | Covers the shower house too | Yes, same system | No, the shower house needs its own path | No | | Design freedom | Low. Every change is a revision (ARM 24.301.1227) | High | Low. The report pins the product | | Published state cost | Under $1,000 in fees (`02-approval-process.md` section 3) | No state fee; per-project special inspection cost | No state fee | | Real cost | Third-party agency contract + a §403.1 quality administrator | Repeated per-project inspection, repeated arguments | Unpublished. Trade press says "tens of thousands" on testing and certification. ISO 17025 lab programme, qualifying plant inspection, annual audits | | Time to first legal sale | A quarter, per `02-approval-process.md` section 5 | Immediate, then an argument at every job | 9 to 18 months on existing criteria; add 1 to 3 hearing cycles if new criteria are needed | | Travels out of state | No. A Montana insignia is worth nothing elsewhere (`02-approval-process.md` section 7) | No | **Yes.** This is route C's one real advantage | ### Sources (section 2) - MCA 50-60-101, definitions: (fetched 13 Sep 2026) - MCA 50-60-401 and 50-60-402: and (both fetched 13 Sep 2026) - ARM 24.301.1245, effect of insignia: (fetched 13 Sep 2026) - ARM 24.301.1227 / .1233 / .1247, changes, revocation, void insignia: , , (cited from `02-approval-process.md`, which fetched them 13 Sep 2026) - ARM 24.301.146, list of Montana IBC modifications, confirming none touches Chapter 17, §104.11, Chapter 19 or Chapter 22: (fetched 13 Sep 2026) - IBC 2021 §104.11, §104.11.1, §104.11.2, Montana viewer: (fetched 13 Sep 2026) - IBC 2021 §1704.2, §1704.2.5, §1704.2.5.1, §1705, Montana viewer: (fetched 13 Sep 2026) - 24 CFR 3282.12, HUD modular home exclusion: (fetched 13 Sep 2026) - ARM 37.111.1201, DPHHS definitions: (fetched 13 Sep 2026) - ARM 37.111.1216, campground service buildings and Table I: (fetched 13 Sep 2026) - Approved Factory Built Building Manufacturers - Montana, sheet dated 9/02/2026: (fetched 13 Sep 2026) - Factory-Built Buildings Permits page, both versions of the FBB definition: (fetched 13 Sep 2026) ### Sources (section 2.3, the evaluation report route) - ICC-ES acceptance criteria index: (fetched 13 Sep 2026) - AC15, Concrete Floor, Roof and Wall Systems and Concrete Masonry Wall Systems: (fetched 13 Sep 2026) - AC04, Sandwich Panels: (fetched 13 Sep 2026); 2009 edition scope text: (fetched 13 Sep 2026) - AC272, Cellular Concrete: (fetched 13 Sep 2026) - AC46, AC322, AC553, AC543: , , , (all fetched 13 Sep 2026) - ESR-1662, Superior Walls Xi, citing AC15 dated February 2010: (fetched 13 Sep 2026) - ESR-1638, Saebi Alternative Building System, evidence submitted with no acceptance criteria cited: (fetched 13 Sep 2026) - ESR-2748, Aerix Mearlcrete cellular concrete, scope limited to roof decks and floor underlayment: (fetched 13 Sep 2026) - Metal Stud Crete system description (ESR-2511 itself could not be retrieved): (fetched 13 Sep 2026) - ICC-ES Rules of Procedure for the Evaluation Committee, rev. June 2025: (fetched 13 Sep 2026) - ICC-ES Rules of Procedure for Evaluation Reports, rev. 13 Oct 2025: (fetched 13 Sep 2026) - ICC-ES acceptance criteria development deadlines: (fetched 13 Sep 2026) - AC509 staff letter and draft, showing the revision history of a new-technology criteria document: (fetched 13 Sep 2026) - ICC-ES renewal fee freeze announcement, the only public pricing item found and it carries no dollar figures: (fetched 13 Sep 2026) - IAPMO UES FAQ, the published timeline: (fetched 13 Sep 2026) - Intertek CCRR: (fetched 13 Sep 2026) - DrJ Certification TER: (fetched 13 Sep 2026) - UL Solutions evaluation reports: (fetched 13 Sep 2026) - PFS-TECO / NFPA Global Solutions BPER directory: (fetched 13 Sep 2026) - IAS AC291, Special Inspection Agencies, 11 Jun 2025: (fetched 13 Sep 2026) - IAS AC157, Fabricator Inspection Programs for Reinforced and Precast/Prestressed Concrete, April 2017: (fetched 13 Sep 2026) - IAS AC98 landing page: (fetched 13 Sep 2026) - IAS AC473, cold-formed steel component manufacturer inspection programs: (fetched 13 Sep 2026) - IAS accreditation criteria index: (fetched 13 Sep 2026). The IAS accreditation programs portal returned HTTP 500 to a direct fetch: (attempted 13 Sep 2026) - MCA 50-60-103: (fetched 13 Sep 2026) - MCA 50-60-201: (fetched 13 Sep 2026) - Montana Approved Alternative Methods and Materials: (fetched 13 Sep 2026) - Frame Building News, "ICC-ES Certification", Karen Knapstein, June 2021. Trade press, cited only for the two-years and tens-of-thousands quotes: (fetched 13 Sep 2026) --- ## 3. The recommendation **Take route A. Put the panel line and the shower house into the Montana factory-built building system under one quality manual, one approved third-party agency and one plant certification, and treat a product evaluation report as a later, optional export tool rather than as the Montana compliance path.** ### Why 1. **The rule already says so.** ARM 24.301.1221(1) requires plan review from "any manufacturer of modular buildings or modular building components", and the standard Montana adopted defines a panelized system as a modular component and a panelized-system maker as a manufacturer. Routes B and C both require Ken to argue that a rule aimed at component manufacturers does not reach him. That is a poor foundation for a plant. 2. **Every route ends with an inspector in the plant.** Route B puts one there under IBC section 1704.2.5, employed by a different project owner each time. Route C puts one there under the ICC-ES Rules of Procedure sections 4.6 and 9.0. Route A puts one there under 1205 section 401.1 at a frequency the agency sets, which for a panel line (section 401.1(14)) can be sampling rather than every piece. The inspector is unavoidable, so take the version that buys the most and costs the least per visit. 3. **The marginal cost of adding the panels to the shower house's system is small.** The shower house is going through route A anyway, assuming the classification question in 2.4 lands the right way. The quality manual is a plant document, not a product document: every clause of 1205 sections 501.1 through 501.17 is written about the plant, the stations, the records and the people. The agency contract is a plant contract (1205 section 601.4). The incremental spend is a second model plan review and the section 103.3 document items, and the PE package needs those anyway for the house to get permitted at any site. 4. **One system is simpler to operate than two.** Two quality systems means two sets of travelers, two sets of forms, two audit trails and two people who have to remember which rules apply to what is on the bed today. In a plant where the same few people do several jobs, that is how nonconformances happen. It is the same reasoning `04-quality-manual-requirements.md` section 7 uses when it sizes the manual for a small crew. 5. **Route C does not do the one thing it is supposed to do.** IBC section 104.11.1 makes a research report "supporting data" for the building official's approval. It is persuasive, not binding. A Montana insignia under ARM 24.301.1245(1) and MCA 50-60-402(3) is binding, and inside Montana that is worth more than any report. ### What the recommendation does not say - It does not say skip the evaluation report forever. Route C's one real advantage is that it travels, and `02-approval-process.md` section 7 shows how little a Montana insignia is worth in Washington or Idaho. If Ken's growth plan is out of state, open the pre-application conversation with ICC-ES and IAPMO UES in parallel with route A, ask whether AC15, AC04 or an ESR-1638-style data package applies, and use the UES quote as a check on the ICC-ES number. - It does not say skip Montana's Approved Alternative Methods and Materials listing. That is cheap, it is statewide, it comes from the same office, and the 3-D printed hemp precedent shows the Bureau will list a novel cementitious wall system by name. Ask for it in the same letter. - It does not say enter plan review now. Route A freezes the design (ARM 24.301.1227, ARM 24.301.1233). Close out the PE package first. The open items in `wall-spec-v1.md` section 4 and in `pe-package.md` are the gate. ### What would change the recommendation | If this happened | Then | |---|---| | The Bureau answers question 1 in section 4 with "panelized systems are not covered, we only review units" | Route A is unavailable for the panel line. Fall back to route B with IBC section 1704.2.5.1 approved fabricator status, plus the Montana alternative-methods listing, and pursue an evaluation report to carry the argument at each jurisdiction | | The Bureau rules the shower house out of the FBB programme on the "readily movable" leg | The shared-system argument weakens but does not fail. The panel line still goes route A on its own, because ARM 24.301.1221(1) does not depend on the shower house. Reprice the shower house as a site-permitted building at every destination | | A third-party agency quotes ongoing panel inspection at a frequency close to every panel | Push back with 1205 section 401.1(14), which expressly lets the agency set the frequency for a panelized system. Get quotes from three agencies. If none will sample, route A's economics change and route B deserves a second look | | Ken's first real market turns out to be out of state | Start route C in parallel immediately. A Montana insignia buys nothing in Washington, which requires an L and I insignia applied before the unit ships from the factory | | Montana adopts a new I-Code cycle | ARM 24.301.1233 revokes the plan review. Ken gets 90 days to pull insignia on the old approval and then re-applies with new fees. Watch the adoption calendar. This is the largest scheduled cost event in route A | | The PE cannot produce a defensible cumulative tolerance for a ten-panel run | Route A stalls at plan review, because section 103.3(4) and section 308.4 both land on the joint. This is an engineering gate, not a regulatory one | --- ## 4. What the Bureau has to decide, and how to ask ### 4.1 The channel **Do not use the Code Interpretation or Technical Advisory form.** That process exists to settle a disagreement between jurisdictions. ARM 24.301.212 requires the requester to describe "the differing or inconsistent code interpretation of the code provision at issue, including the name of the jurisdiction(s) that are involved in the inconsistent code interpretation", then runs a 30-day comment period and a ballot of building officials before an interpretation becomes binding. The printed form asks for the affected project address, the affected parties, whether the AHJ has already been asked in writing, and whether an appeal has been filed. Ken has none of that. He has a programme question for the office that runs the programme. The right channel is a plain written question to the Factory-Built Building Program: ``` Building Codes Program Building and Commercial Measurements Bureau Montana Department of Labor and Industry PO Box 200517, Helena, MT 59620-0517 Physical: 301 South Park Ave., Floors 4 and 5, Helena Phone: (406) 841-2056 Email: buildingcodes@mt.gov ``` For the alternative-methods question specifically, the same office and the same email. For a code interpretation question, the contact printed on the request form is Eric Copeland, (406) 841-2008. Ask by email, ask for a written answer, and say plainly that Ken is deciding whether to build a plant on the answer. Keep the six questions in one message so the Bureau sees the whole picture and so one reply settles everything. ### 4.2 The six questions, drafted so an official can answer them Each is written to be answerable yes or no, or with a short choice. That is the point. A question like "how should we handle this" gets a phone call and no record. --- **Question 1. Does the factory-built building programme cover a plant that makes panelized systems but never makes a module?** > We intend to operate a plant in Montana casting cellular-concrete wall, roof and floor panels on cold-formed > steel studs. The panels are cast flat, the studs and steel are embedded in concrete, and the completed panel > cannot be inspected at the building site without destroying it. Under the definitions in chapter 2 of the > ICC/MBI 1200 and 1205 Standards, which the department incorporated at ARM 24.301.1203, we read the panel as a > PANELIZED SYSTEM, which is a MODULAR COMPONENT, which makes us a MANUFACTURER. > > ARM 24.301.1221(1) says "Any manufacturer of modular buildings or modular building components shall apply to > the bureau for plan review of a model or model group before construction." > > **Is the bureau's position that our panel line must obtain model plan review under ARM 24.301.1221, a > quality assurance manual approval under ARM 24.301.1223, and third-party in-plant inspection under ARM > 24.301.1213, in the same way a module manufacturer must? Yes or no.** --- **Question 2. If yes, what does a panel carry instead of a state insignia, and what does the bureau charge to review a panel model?** > ARM 24.301.1241 and ARM 24.301.1243 are written around "units", and ARM 24.301.1205(6) defines a unit as a > module. A wall panel is not a module, so we do not believe a state insignia is issued for it. ICC/MBI 1205 > section 701.1 says "Modular components or modules of an approved modular building shall be marked with an > insignia or other identification supplied by the third-party inspection agency." > > **(a) Is the third-party inspection agency's certification label under ICC/MBI 1205 section 701.1 the correct > and sufficient marking for an approved panel, with no state insignia and no insignia fee? Yes or no.** > > **(b) The plan review fee tiers at ARM 24.301.1261 are stated as "units with one or two parts", "three or > four parts" and "five or more parts". Which tier applies to a wall panel model, or to a model group covering > a family of panel sizes? Please state the fee we should send.** --- **Question 3. What acceptance does an approved and labelled panel carry at the job site?** > ARM 24.301.1245(1) says units bearing the insignia are acceptable statewide "without further inspection or > fees except for zoning, utility connections, and foundation permits as required by the authority having > jurisdiction." That sentence is written about units. > > **When a panel built under an approved model plan, in a plant under third-party in-plant inspection, arrives > at a job site carrying the agency's certification label, may the local building official require the concealed > in-panel construction to be re-inspected or opened, or is the in-plant inspection accepted? Please say which.** --- **Question 4. Is the shower house a factory-built building?** > We also intend to build a complete 1- or 2-bathroom shower building in the same plant, with all plumbing, > drainage, water heating and electrical distribution installed in the factory, on a welded steel skid that > forms the floor framing and carries fork pockets and lifting lugs for transport and placement. > > The definition at MCA 50-60-101(9)(a) and ARM 24.301.1205(4) reads "a factory assembled structure or > structures equipped with the necessary service connections, but not made so as to be readily movable as a > unit or units and designed to be used with a permanent foundation." > > We will design and stamp the unit for installation on a permanent foundation system as defined in chapter 2 > of ICC/MBI 1200, meaning embedded concrete or concrete-block piers with engineered anchorage resisting the > prescribed uplift and sliding forces. The steel skid is the transport, lifting and handling frame and the > floor structure, not the foundation. The installation instructions will require the permanent foundation and > will not describe relocation. > > **On that design, is the unit a factory-built building requiring a Montana insignia? Yes or no. If the answer > is no because of the "not made so as to be readily movable" clause, please say what changes to the product > would make the answer yes.** --- **Question 5. Can one quality assurance manual and one third-party agency contract cover both product lines?** > ICC/MBI 1205 chapter 5 is written about the plant: its stations, its records, its people and its forms. We > intend to submit one quality assurance manual under ARM 24.301.1223 covering the plant, with product-specific > inspection procedures for the panel line and for the shower house, and to contract one approved third-party > inspection agency for the plant. > > **Will the bureau accept one quality assurance manual and one third-party agency contract covering both > product lines and both model plan reviews? Yes or no.** --- **Question 6. Can the panel system be listed as an approved alternative method or material?** > The department publishes a list of Approved Alternative Methods and Materials, citing 50-60-201, MCA, and it > currently includes a 3-D printed hemp building system approved as an alternate means of compliance for all > types of construction. > > **(a) What must we submit for the bureau to consider listing our cellular-concrete and cold-formed-steel > panel system on that list, and is there a form or a fee?** > > **(b) Would such a listing be binding on certified city, county and town code enforcement programs, or only > on the state programme?** --- **One more, worth adding because it costs nothing to ask and it is the biggest lever on ongoing cost:** > ICC/MBI 1205 sections 301.2 and 312.2.1 give the AHJ the option to conduct remote virtual inspections. > **Does the bureau permit remote virtual in-plant inspections for factory-built buildings and components, and > will it accept them from an approved third-party agency?** ### 4.3 What to attach Keep the attachment set small and make every item answer a question the official will otherwise have to ask. | Attachment | Which question it serves | Where it comes from | |---|---|---| | A one-page product description with two photographs or renderings: the cast panel on the bed, and the finished shower house on the skid | All of them | The animator renderings | | A typical wall panel section drawing showing the 2 inch skin, the channel and mesh zone, the studs, the 5 inch skin pour, the cladding and the cavity fill, with the note that the steel is buried | Question 1. It is the evidence that the panel cannot be inspected at the site | `wall-spec-v1.md` section 2 and `wall-contract.md` | | The panel key plan for the reference house: the building perimeter with all 34 panels numbered | Questions 1 and 2. Shows what a "model" means for a panel line | `panels(cfg)` output, formatted as a sheet | | A draft written sequence of construction, plant and site, with the rough-in inspection hold point before the cavity fill marked | Questions 1 and 3. It is one of the four items ICC/MBI 103.3 requires and it shows good faith | Section 6 of this file | | The shower house general arrangement: plan, elevations, the skid, and the proposed pier foundation and anchorage detail | Question 4. This is the attachment that answers the permanent foundation leg | The PE, per `03-codes-and-classification.md` gap 3 | | A short statement of the codes the products are designed to, with the design loads: wind Vult, construction type, seismic design category, ground snow load | Questions 1 and 4. It is what ARM 24.301.1221(2)(e) will ask for anyway | The PE design basis | | The name of the third-party inspection agency Ken intends to contract, if one is chosen | Questions 1 and 5. Both application forms mark that field required | `02-approval-process.md` section 4 | Do not attach the full PE package, the estimate workbook or the animation. The Bureau is being asked six questions, not to review a submittal. --- ## 5. The practical build-out This section says what has to exist in the plant and on paper for route A. It is deliberately thin where `04-quality-manual-requirements.md` is thick. **The manual is layer 4's job. This is the cross-reference and the panel-specific delta.** ### 5.1 What already exists in layer 4 and needs no change `04-quality-manual-requirements.md` section 3 is a 30-item required-content outline built from ICC/MBI 1205 chapter 5, the Montana list, HUD and IAS AC157, and section 7 is a recommended structure for Ken's plant with a concrete-control chapter that a normal modular manual does not have. **All of it applies unchanged to a panel line**, because every clause in 1205 chapter 5 is a plant clause, not a product clause, and because the concrete control chapter (layer 4 section 4, mix design, batching, cast density, cylinders, cure, bed and form control, mesh and embedment placement, dimensional tolerances, surface acceptance) is about the panel already. Nothing in layer 4 needs to be rewritten because of this document. ### 5.2 What layer 4 needs added, because of the panelized-system rules Nine additions. Each names the layer 4 section it belongs in, so the two documents fit together. | # | Add this | Into layer 4 section | Because | |---|---|---|---| | 1 | **Products covered** must name the panel line as a panelized system and the shower house as a module, in those words, and state which approvals cover which | 1.2 "Products covered" | 1205 section 501.1 requires the cover to identify the manufacturer and the agencies. The reviewer needs to see at once that one manual covers two kinds of output | | 2 | **Panel serial numbering and key-plan numbering** as a single traceable scheme: model number, key-plan panel number, serial number, cast date, bed and slot, mix batch | 20 "Serial numbering and traceability", and section 7 item 7.1 the panel traveler | 1205 section 501.13 covers modules and modular components. 1200 section 103.1(3) requires unique numbers on delivered components | | 3 | **Marking procedure**: what the panel marking is physically, where it goes, when it is applied, who applies it, and how it survives cladding and cavity fill | 21 "Insignia and label control" | 1205 section 701.1 and 701.2. The agency's label must be affixed so it cannot be removed without destroying it | | 4 | **Two label streams**, kept separate: Bureau insignia for shower house units (ARM 24.301.1243, 12-month expiry, no stockpiling), agency certification labels for panels (1205 section 701.3, agency-controlled, agency keeps the serial list) | 21 "Insignia and label control" | The two label systems have different owners, different records and different failure modes. Mixing them in one log is how a void insignia gets used | | 5 | **Panel dimensional tolerance table** with an acceptance band for width, height, thickness, squareness, bow, twist, face flatness and opening location, plus a **cumulative run tolerance** for a ten-panel wall | 4.8 "Panel dimensional tolerances" (already flagged as having no published source) | 1200 section 308.4 hands panel attachment tolerance to the attachment device maker, which does not answer a cumulative run. The PE sets it | | 6 | **Special inspection list** naming which characteristics of the panel are special-inspection items and who signs each | 14 "In-process inspection points and hold points" | 1200 and 1205 section 103.3(1). See 5.3 below for the draft list | | 7 | **Written sequence of construction**, plant and site, as a controlled document referenced by the manual | 3 "Documents and drawings" and section 7 item 7.1 | 1200 and 1205 section 103.3(2) | | 8 | **Notification procedure**: notify the AHJ before commencing fabrication on a project, per the approved plan | 30 "Notification duties" (already listed) | 1200 section 505.2. Layer 4 has it; it needs a named trigger for a panel order, which is not obvious when the plant runs continuously | | 9 | **Quality assurance administrator qualification** stated against 1205 section 403.1, and the supervisor against section 403.2, with the actual named people and their credentials | 2.5 "Personnel qualifications by role" | Section 403.1 asks for a Registered Design Professional with two years of modular or component product experience and two years of quality assurance experience. Layer 4 section 8 should carry this as a hiring gate | ### 5.3 The special inspection list, drafted 1200 section 103.3(1) requires the construction documents to name "systems and components requiring special inspections". Nobody has written one. This is a first draft for the PE to accept, reject or extend. It is not stamped and it is not authority. | # | Characteristic | When | Who signs | Evidence retained | |---|---|---|---|---| | 1 | Bed and form dimensions, liner condition, end board position for a cut panel | Before each pour | Plant QC | Pre-pour bed check form | | 2 | Stud and track type, gauge, spacing and length against the approved panel drawing | Before skin pour | Plant QC | Panel traveler | | 3 | Stud-to-track screw type, count and location | Before skin pour | Plant QC, sampled by the agency | Panel traveler | | 4 | Channel row positions and spacer placement | Before skin pour | Plant QC | Panel traveler | | 5 | Mesh type, lap and position within the skin zone, with cover measured | Before skin pour | Plant QC, sampled by the agency | Panel traveler with measured cover | | 6 | Opening framing: jambs, cripples, header and sill against the drawing | Before skin pour | Plant QC | Panel traveler | | 7 | Lifting insert type, location and embedment | Before skin pour | Plant QC | Panel traveler, plus the proof test record if the inserts are proof tested | | 8 | Mix design identity and batch record for the pour | At the pour | Batch operator | Batch ticket | | 9 | Cast density at the point of placement | At the pour | Plant QC | Density log against the acceptance band | | 10 | Cylinder set cast, identified and cured | At the pour | Plant QC | Cylinder log | | 11 | Skin pour depth achieved, meaning the 1.5 inch penetration into the studs | At the pour | Plant QC | Panel traveler with measured depth | | 12 | Cure time and temperature to release | At strip | Plant QC | Cure log | | 13 | Release strength, meaning the cylinder break at the release age | At strip | Plant QC | Break report | | 14 | Panel dimensions and defects against the acceptance criteria | After strip | Plant QC, sampled by the agency | Final inspection form | | 15 | Marking applied, correct and legible | Before shipping | Plant QC | Final inspection form, label log | Items 3, 5, 7 and 11 are the ones that become invisible after the pour. Those four are the heart of the whole off-site argument and they are the ones the agency should witness most often. ### 5.4 The plant gate list, in order `04-quality-manual-requirements.md` section 8 already lists what must be true before the manual can honestly be submitted. This is the regulatory ordering that sits over it, from `02-approval-process.md` section 9, with the panel-specific items marked. 1. Written answers from the Bureau to the six questions in section 4. **Nothing below is worth spending money on until question 1 is answered.** 2. PE package closed out: joint screw pattern, slab anchor and base detail, corner detail, panel tolerances, the shower house bearing and anchorage sheet, the transport load case. Route A freezes the design, so close it first. 3. Third-party agency selected and contracted, with a written quote for panel-line inspection frequency and whether remote virtual inspection is available. 4. Quality assurance administrator identified against 1205 section 403.1, and the supervisor against 403.2. 5. Quality manual written to 1205 chapter 5 plus the nine additions in 5.2, submitted with the $20 fee. 6. **Manual approved. Hard gate.** ARM 24.301.1223(2): the manual must be approved before plan review approval. 7. Model plan review applications submitted: one for the panel model or model group, one for the shower house model. Each with the chapter 3 items, the section 103.3 items for the panel, the design loads on the first page, the named agency and the fees. 8. Plan approval. Ken appears on the approved manufacturer list. 9. Third-party initial plant certification: 100 percent inspection of not fewer than one panel and one shower house, plus verification that the quality process functions (1205 section 401.1(12)). 10. Production under ongoing inspection. Agency label on panels; Bureau insignia applied by Ken to each shower house unit. --- ## 6. How the house gets inspected at the site once the panels are approved The panel approval moves the inspection line. It does not remove it. This section says where the line lands and who signs the two things that get buried at the site rather than in the plant. ### 6.1 The split | Work | Inspected by | Under | Visible? | |---|---|---|---| | Everything inside the panel: stud-to-track screws, channel rows, mesh position, skin pour depth, lifting inserts, concrete density and strength | Plant QC and the third-party agency | 1200 section 104.2, 1205 section 312.2 | Only in the plant. Gone after the pour | | Slab, footings, anchor bolts or post-installed anchors | Local inspector, or the state programme | Ordinary foundation permit. ARM 24.301.1245(1) expressly reserves foundation permits to the AHJ | Yes | | **Panel-to-slab anchorage** | Local inspector | 1200 section 104.3(2), connections between off-site components and site-built work | Yes, until the base is covered | | **Panel-to-panel joint screws through the mating edge studs** | Local inspector | 1200 section 104.3(1), interconnections between off-site components installed at site | **Only until the cladding goes on.** See 6.3 | | Electrical and plumbing rough-in in the open stud cavity | Local inspector, ordinary trade inspection | NEC 2020 and UPC 2021 as adopted | **Only until the cavity fill.** See 6.3 | | Cladding sheet attachment to the exterior stud flanges | Local inspector | 1200 section 104.3 | Only until the fill | | **Cavity fill** | Nobody, as things stand today | Nothing written | No. It is inside a closed wall | | Top track, rake or gable infill, roof strips and roof pour | Local inspector | Ordinary structural inspection | Yes | | Air sealing at the panel joints, and the 4 ACH50 blower door test | Local inspector or an approved rater | ARM 24.301.161 as amended, R402.4.1.2 | The test is at the end, the detail is buried | ### 6.2 What the local inspector still checks Everything outside the panel, and every connection made on site. 1205 section 102.3.1 lists the building official's duties for an off-site component arriving at a site, and all five reach a panel: > 1. Verify through inspection that the modular building or component displays the required certification label > and the label of the third-party inspection agency or comply with the labeling requirements of the AHJ. > > 2. Verify through inspection that the modular building or component has not been damaged in transit to a > degree that would render it unsafe. If the building or component has been damaged, the building official is > authorized to require remedies deemed necessary. If the modular building or component has been structurally > damaged, the building official is authorized to require evaluation by a registered design professional or > test on structural elements for strength. > > 3. Verify that all off site components are installed on site in accordance with the approved plans. > > 4. Prevent the use or occupancy of a modular building that in the opinion of the building official contains a > serious defect or imminent safety hazard and notify the AHJ immediately. > > 5. Notify the state program administrator, if applicable, of any violations of this standard. Item 1 is why the panel marking has to be legible at the site, on the face the inspector can reach, before the cladding goes on. Item 2 is why the erection instructions need a damage-acceptance section: a chipped corner on a cast panel is cosmetic, a crack through the skin over the mesh is not, and nobody has written down which is which. That belongs with the surface and defect acceptance criteria that layer 4 section 4.9 already flags as having no published source. ### 6.3 The two things buried at the site, and who signs them This is the question the task asked and it deserves a straight answer. **Right now nobody signs either one, because neither has been detailed or scheduled.** Here is what has to change. **The joint screw pattern.** - It is a **panel-to-panel attachment** under 1200 section 103.3(4), so the detail is mandatory content of the construction documents. It does not exist yet; `wall-spec-v1.md` section 2 carries 8 x #10-16 per joint as an explicit assumption and section 4 item 2 lists it as open. - It is an **interconnection between off-site components installed at site** under 1200 section 104.3(1), so it is expressly on the on-site inspection list. - It is visible from the exterior only until the cladding sheet goes on, and from the interior not at all, because the finish face is the interior. - **Who signs it:** the local building official, at a scheduled inspection, **before the cladding goes on**. That inspection does not exist in any current sequence. It has to be created, named in the written sequence of construction (1200 section 103.3(2)) and named in the erection instructions (1200 section 804.1(1)) as a hold point. - **What the inspector needs in hand:** the stamped joint detail with screw type, count, spacing and edge distance, and the key plan so he can walk the joints in order. Give him a joint sign-off sheet with one line per joint. - **Belt and braces:** the erector should photograph every joint before cladding, against the key plan panel numbers, and the photographs go into the project record. That is cheap, it is what a third-party agency would ask for, and it is the only evidence that survives. **The cavity fill.** - The fill is site work on the house. It is the last irreversible step and it buries the MEP rough-in, the cladding fasteners from the inside, and the joint screws. - **No adopted rule names it.** It is not a connection, so 1200 section 104.3 does not reach it directly. It is not plant work, so 1205 section 312.2 does not reach it. It falls under 1200 section 804.1(8), "installation of all other items to be installed or completed on site", which makes it the **manufacturer's instruction** problem, not the inspector's. - **Who signs it:** nobody, unless Ken makes someone. Three options, and Ken should pick one and write it into the erection instructions: 1. **Make it a special inspection item under IBC chapter 17 at the site**, named in the construction documents by the PE. That puts an approved agency there for the pour, employed by the owner. Most rigorous, most expensive. 2. **Make it a manufacturer-witnessed operation.** Ken's own crew pumps the fill, or a Ken-trained erector does it under a written procedure, with a signed fill record per wall: mix, batch, density, volume placed against calculated volume, date, who. The volume check is the real control, because a cavity that takes less than the calculated volume has a void in it and nobody will ever see it. 3. **Do nothing**, which is where the product sits today. - **The rough-in inspection has to come first, and it has to be a hold point with teeth.** This is already gap 20 in `03-codes-and-classification.md`. A builder who pumps before the electrical and plumbing rough-in inspection has destroyed the inspection, and the remedy is to open a cast wall. The erection instructions have to say, in the imperative, that no fill is placed until the rough-in inspections are signed off, and the sequence statement has to show it. **The suggested site sequence, with the inspection points named.** This is what goes in the written sequence of construction and in the erection manual. ``` 1 Slab and anchors -> AHJ foundation inspection 2 Set panels, brace, anchor to slab 3 Joint screws through mating edge studs -> AHJ: panel-to-panel and panel-to-slab connection inspection. HOLD POINT. Photograph every joint against the key plan. 4 Electrical and plumbing rough-in in the open cavity -> AHJ electrical rough-in inspection -> AHJ plumbing rough-in inspection HOLD POINT. No fill before both are signed. 5 Cladding sheets on the exterior stud flanges 6 Cavity fill pumped -> fill record signed: mix, density, volume placed vs calculated, per wall 7 Top track, rake or gable infill 8 Roof strips set, top pour, membrane -> AHJ structural inspection 9 Air sealing complete 10 Blower door test, 4 ACH50 -> ARM 24.301.161 R402.4.1.2 as amended 11 Finishes, final -> AHJ final inspection ``` Two notes on that sequence. Step 3's inspection is new and Ken has to ask for it, because no local inspector will know to schedule an inspection for a wall system he has never seen. Step 6 has no AHJ line because no rule puts one there; the fill record is Ken's own control and it is the only thing standing between a void in a wall and a warranty claim in five years. ### 6.4 What the erection instructions have to say 1200 section 801.1 and section 804.1 set the contents, and section 804.1's eight items map onto this product as follows. This is the table of contents for a document that does not exist yet. | 804.1 item | For the house | For the shower house | |---|---|---| | 1. Connecting panels for strength and rigidity | Joint screw pattern, corner detail, slab anchor, bracing until the roof is on | Panel joints are plant work; the site connection is the anchorage to the piers | | 2. Air barrier, vapour barrier, insulation, cladding, roofing and flashing at the joints | The panel joint air seal, the wall-to-roof line, the cladding joint, window and door flashing. This is the 4 ACH50 detail | Same, all plant work except the roof-to-wall at delivery damage repairs | | 3. Connecting ducting, piping and wiring, sealing and insulation | The rough-in in the open cavity, and the hold point before fill | Water in, sewer out, power in: four connections | | 4. Fire separations and fire blocking | Not likely to bind on a detached single-family house. Site dependent | Not likely to bind on a detached 250 sf building. Site dependent | | 5. Foundation loads, anchorage details, anchorage device capacity | Slab design loads and the anchor schedule | **The pier foundation and anchorage sheet.** This is gap 3 in `03-codes-and-classification.md` and it is also the answer to question 4 in section 4 | | 6. Maximum foundation support and spacings | Slab, so not a spacing question | **Maximum pier spacing and minimum bearing pressure.** Same sheet | | 7. Connection of services | Water, sewer, power, and gas if any | Same | | 8. All other items installed or completed on site | **The cavity fill**, the top track, the rake or gable infill, the roof strips, the roof pour and membrane, the clerestory glazing | The accessible landing and ramp, the utility connections, any shipped-loose items | Item 5 and item 6 for the shower house are one drawing, and that one drawing also answers the classification question in 2.4, the DPHHS "permanent construction" question, and gap 3 in layer 3. It is the highest-value sheet in the whole programme and it has not been drawn. ### Sources (sections 4, 5 and 6) - ARM 24.301.212, code interpretations: (fetched 13 Sep 2026) - Request for a Code Interpretation or Request for a Technical Advisory form, Montana DLI Building Codes Program, PDF created 2019 and modified 2023, no revision number printed: (fetched 13 Sep 2026) - Code interpretation request page: (fetched 13 Sep 2026) - ICC/MBI 1205-2021 section 102.3.1, building official duties, and sections 103.3, 301.2, 312.2, 401.1, 403, 501, 701: (fetched 13 Sep 2026) - ICC/MBI 1200-2021 sections 103.3, 104.2, 104.3, 308.4, 505.2, 801.1, 804.1: (fetched 13 Sep 2026) - ARM 24.301.1223, QA manual as the hard gate: (fetched 13 Sep 2026) - ARM 24.301.1245, effect of insignia and the foundation permit carve-out: (fetched 13 Sep 2026) - ARM 24.301.161, the 4 ACH50 blower door requirement, cited from `03-codes-and-classification.md` section 1.2 which fetched it 13 Sep 2026: - Building Codes Program contact details: (fetched 13 Sep 2026) --- ## 7. Open items and what is not confirmed Numbered so they can be closed one at a time. Items 1 through 6 are the questions in section 4 and they are the ones that block spending. 1. **Whether ARM 24.301.1221(1) reaches Ken's panel line in the Bureau's view.** The text says it does. The Bureau has not said so. Everything in this document depends on it. Question 1 in section 4. 2. **What a panel model costs to review**, given that every fee tier in ARM 24.301.1261 is worded around "units with one or two parts". Question 2(b). 3. **Whether the agency certification label under 1205 section 701.1 is the correct and sufficient marking for a panel in Montana, with no state insignia.** Question 2(a). 4. **Whether ARM 24.301.1245(1) acceptance extends to a labelled panel.** The sentence is written about units. Question 3. 5. **Whether the shower house is a factory-built building** on the "not made so as to be readily movable" leg, even when designed and stamped for a permanent pier foundation. Question 4. This is the single largest commercial unknown in the file. 6. **How to get on the Approved Alternative Methods and Materials list**, what it costs, and whether it binds certified local programmes. Question 6. 7. **Whether the Bureau permits remote virtual in-plant inspection.** The standard allows it at 1205 sections 301.2 and 312.2.1. Montana has not published a position. It may be the biggest single lever on ongoing inspection cost for an out-of-state agency. 8. **Whether 1205 section 403.1's "Registered Design Professional" requirement for the quality assurance administrator is enforced for a component-only plant.** ARM 24.301.1223 adopts chapter 5, ARM 24.301.1213 adopts section 401. Section 403 sits in the same chapter as 401 but is not separately named in any Montana rule. 9. **Whether relocating an insignia'd shower house voids anything.** I found no Montana rule that voids an insignia on relocation and none that blesses it. ARM 24.301.1249 covers alteration, not relocation. It is a sales fact and it needs an answer. 10. **Section numbers in the published ICC/MBI 1200-2021 and 1205-2021.** Everything quoted here comes from the ICC-posted approved ballot drafts. Buy both and verify. This is open item 1 in layer 4 and it is still open. 11. **AC272's own scope**, meaning whether the ICC-ES cellular concrete criteria forbid structural use or merely have not been applied to it. Only ESR-2748's scope was read, not the criteria. 12. **Whether AC04's June 2019 edition keeps the 2009 edition's catch-all scope sentence.** The current edition is paywalled. 13. **ESR-2511 (Metal Stud Crete)**, the closest published system to Ken's geometry. The report could not be retrieved and the criteria behind it are unknown. 14. **ICC-ES and IAPMO UES fees.** Neither publishes a schedule. Only trade-press figures exist. 15. **IAS AC98 and AC157 current edition dates.** The AC98 PDF would not open and AC157 is a 2017 document that may have been superseded. 16. **Whether IAS publishes any numbered criteria for modular or off-site inspection agencies.** The IAS portal returned HTTP 500. Search snippets suggest accreditation runs against ICC/MBI 1200 and 1205 themselves. 17. **IBC section 1704.2.4 and section 110.3 verbatim.** The argument in 2.2 that a site special inspector cannot honestly sign off concealed plant work he never saw is reasoning from the structure of chapter 17, not from quoted text. 18. **Panel dimensional tolerances and surface defect acceptance criteria.** No published source for this product, per layer 4 section 10 items 6 and 7. Section 308.4 does not fill the gap. The PE has to set them. 19. **The transport design acceleration** for the panel on a trailer, which is layer 3 section 7 item 1 and is still unanswered. 1200 chapter 7 covers permitting, route, weight and method and sets no g-load. 20. **"Permanent construction" at ARM 37.111.1216(1)(a) is an undefined term.** The defined terms at ARM 37.111.1201 are "permanent foundation" and "permanent structure", and they are not the same thing. A sanitarian's reading of 1216(1)(a) is a judgment call. Designing for embedded piers is the strongest available evidence, not a guarantee. --- ## Consolidated source list All fetched 13 Sep 2026. **The two standards** - ICC/MBI 1200-2021 approved ballot draft: - ICC/MBI 1205-2021 approved ballot draft: - ICC Digital Codes listing for ICC/MBI 1200-2021 (returns 403 to an automated fetch, open it in a browser): - NEEP explainer on ICC/MBI 1205, background only, not the standard: **Montana rules** - ARM 24.301.1201, 1203, 1205, 1213, 1217, 1221, 1223, 1227, 1233, 1241, 1243, 1245, 1247, 1261, 1263: and the same URL pattern for each number - Subchapter 24.301.12 index: - ARM 24.301.146, IBC modifications: - ARM 24.301.212, code interpretations: - ARM 37.111.1201 and 37.111.1216, DPHHS campground rules: , **Montana statute** - MCA 50-60-101: - MCA 50-60-103: - MCA 50-60-201: - MCA 50-60-401: - MCA 50-60-402: - MCA Title 50 ch. 60 part 4 index: **Montana programme pages and forms** - Factory-Built Buildings Permits: - Approved Factory Built Building Manufacturers, sheet dated 9/02/2026: - Approved Alternative Methods and Materials: - Code interpretation request page and form: , - Current Codes: **Codes** - IBC 2021 chapter 1 on the Montana viewer, section 104.11: - IBC 2021 chapter 17 on the Montana viewer, sections 1704 and 1705: **Federal and other states** - 24 CFR 3282.12, HUD modular home exclusion: - WAC 296-150F-0020, Washington definitions: **Evaluation reports and accreditation**: see the Sources block after section 2.3, which lists all 27 of them. **Project files referenced** - `docs/wall-contract.md`, `docs/wall-spec-v1.md`, `docs/showerhouse.md` - `docs/montana/01-statute-and-rules.md`, `02-approval-process.md`, `03-codes-and-classification.md`, `04-quality-manual-requirements.md` - `docs/engineering/pe-package.md`, `docs/engineering/standards-register.md`