Roof options for the 40' × 29'-11" panel house

All three use the roof-panel system from the roof project (cellular concrete cast on cold-formed studs, picked and set on the wall tops), sized to this house: bearing on the front and back walls plus the bedroom wall 15.5' in from the front. The roof project's spec found a 6" stud cannot clear-span past about 10.5', so every option names the stud it needs. Every price on this page comes from the estimate itself — the same engine the configurator uses — so the roof strips are quoted at the price the plant sells them for and the site work is the crew, the crane and the top pour actually needed for that shape. All three options are built into the 3D model — pick one with the “roof design” switch in the control panel, or open it directly: Option 1 · Option 2 · Option 3. All three are priced in the estimate and in the configurator's “Compare roofs” tab, where you can price them for a house of any size.

Option 1

Low-slope flat roof

built into the model · play the build

as designed in the roof project

Roof area	1,341 sf	Panels	3 × 14' wide
Spans (wall to wall)	15.5' + 13.5'	Studs	800S162-68 @ 16" (8" studs) or 600S162-68 @ 12" — PE to pick; the 15.5' front span is past the 6" stud's 10.5' limit
Panel	13.5" thick · 44 psf dead	Slope	1/16"/ft toward the back, drains behind the house
Cellular concrete	60.0 yd³ neat	Heaviest pick	10,259 lb

Roof panels, cast at the plant and delivered	$33,000
Roof work on site (top pour, crane 1 day, membrane)	$23,900
Roof, as bought	$56,900 · $42/sf
The whole house with this roof	$284,300 · lowest

Cheapest: least roof area, one pick day, the roof project as built
Flat 9' ceiling everywhere; the cast underside is the finished ceiling
Simplest wall tops: one continuous top track, no gable or clerestory panels

Needs 8" studs (or 6" at 12") because the open zone is 15' deep
Low slope: relies on the membrane; ponding risk if the slope is lost
No attic; all roof drains run to the back wall

Option 2

Gable roof, 4:12

built into the model · play the build

ridge over the bedroom wall, vaulted open zone

Roof area	1,511 sf	Panels	6 × 14' wide
Spans (wall to wall)	18.0' + 16.0'	Studs	1000S200-97 @ 16" (10" studs, roof spec Option B) — clear-spans each slope; 6" studs would need a mid-slope purlin
Panel	15.5" thick · 50 psf dead	Slope	4:12 front, 4.0:12 back (the ridge sits over the bedroom wall); ridge 15'-4" above the floor, eaves at the wall tops
Cellular concrete	78.2 yd³ neat	Heaviest pick	6,084 lb

Roof panels, cast at the plant and delivered	$39,600
Roof work on site (top pour, crane 2 days, membrane, ridge beam, gable ends)	$35,700
Roof, as bought	$75,300 · $50/sf
The whole house with this roof	$306,700 · $22,400 more

Vaulted ceiling over the whole open zone, 9' at the walls rising to ~15' at the ridge
Sheds rain both ways with real eaves; membrane is a safety, not the whole system
Six lighter picks (~6,000 lb) instead of three 10,000 lb picks

Most roof area and concrete; 10" studs add ~12 psf and cost
Ridge beam plus two gable-end wall triangles are extra items
Top pour on a 4:12 slope needs a stiffer cellular mix and screeding uphill

Option 3

Shed roof to the view, 1:12

built into the model · play the build

front wall raised, clerestory glass over the big windows

Roof area	1,387 sf	Panels	3 × 14' wide
Spans (wall to wall)	15.5' + 13.5'	Studs	800S162-68 @ 16" (8" studs) — same spans as Option 1
Panel	13.5" thick · 44 psf dead	Slope	1"/ft rising to the front; front wall 12'-6", back wall 10'; drains to the back
Cellular concrete	60.3 yd³ neat	Heaviest pick	10,617 lb

Roof panels, cast at the plant and delivered	$34,100
Roof work on site (top pour, crane 1 day, membrane, rake infill, clerestory glass)	$27,900
Roof, as bought	$62,000 · $45/sf
The whole house with this roof	$297,800 · $13,500 more

Ceiling rises toward the view: 9' at the back, ~11'-6" at the front glass
A clerestory band above the seven windows: more light and view without bigger panels
One plane, three picks, drains away from the view side like Option 1

Front wall panels are taller than the 10' standard (or a separate clerestory frame)
Same 8" stud requirement as Option 1
Side walls B and D get a sloped top track

Side by side

	Option 1 · Low-slope flat roof	Option 2 · Gable roof, 4:12	Option 3 · Shed roof to the view, 1:12
Roof area	1,341 sf	1,511 sf	1,387 sf
Panels / picks	3 · max 10,259 lb	6 · max 6,084 lb	3 · max 10,617 lb
Cellular concrete	60.0 yd³	78.2 yd³	60.3 yd³
Studs	800S162-68 @ 16"	1000S200-97 @ 16"	800S162-68 @ 16"
Ceiling	9' flat	9' to 15'-4" vaulted	9' back to 12'-6" front
Roof panels from the plant	$33,000	$39,600	$34,100
Roof work on site	$23,900	$35,700	$27,900
Roof, as bought	$56,900	$75,300	$62,000
The whole house with this roof	$284,300	$306,700	$297,800

Basis: footprint 40' × 29'-11" from wall.config.json; bedroom bearing wall at 15' inside from the front (floor-plan.json). Cellular concrete at 35 pcf, 4 psf steel; picks at the 6.5" ground pour. Rates from the roof estimate; ridge beam, gable infill, taller front panels and clerestory glazing are allowances to be replaced with quotes. Edit scripts/roof-options.mjs to change any of these.