Whole-project calculator
Garage Conversion / ADU Material Calculator
Plan floor build-up, infill framing, partitions, insulation, drywall, openings, and directional pricing for a garage-to-living-space conversion.
Can this conversion work?
You can read the plan now - the answers below sharpen itNo blocker is modeled so far. Until these readiness areas are confirmed, treat the material list and total as planning-level.
Feasibility review · 6 areas
Review space, shell / site, life-safety, MEP, and local-approval readiness before ordering.
Headroom
Needs review
7 ft 9 in remaining after the modeled floor build-up; ceiling drops, ducts, and soffits are not deducted. Verify final clear height against the locally adopted R305 requirements.
Egress
Needs review
Egress and habitable occupancy details still need review.
Shell eligibility
Needs review
Structural shell, slab, foundation, decay, or site overlay details still need review.
Fire / life-safety
Needs review
Fire separation, penetrations, dwelling-unit separation, or smoke / CO details still need review.
MEP routing
Needs review
Electrical, sewer, exhaust, HVAC / ventilation, or utility routes still need review.
Utility / local review
Needs review
Local or trade readiness still needs review.
Current fit
Headroom 7 ft 9 in remaining Egress 1 of 2 windows Bath core about 5 ft x 10 ft
Bath / layout (planning allowance) The bath core fits the modeled partition run. Fixture clearances, centerlines, shower size, and door swing are not checked - this is a planning allowance, not a verified layout.
2D plan
Schematic assembly plan
Schematic garage-conversion view of a 20 ft x 20 ft attached garage shell with a 16 ft x 7 ft new front wall at the former garage opening, 12 lf of interior partition, and a self-leveler + xps + subfloor + lvp floor path.
3D assembly
Interactive 3D
Rotate the model, toggle assemblies, and inspect labeled material callouts.
Material theme
Leveled living-space conversion
Self-leveler plus insulated subfloor path for a mainstream attached conversion finish stack.
Material tier comparison
Price this same conversion with each floor build-up path, using your current inputs. With slab slope above 2 in, the calculator builds the leveled-floor path as a sleeper subfloor automatically.
Totals marked * are priced-subtotal-only; some lines in that plan have no live price yet.
This comparison uses our reference prices, so your own prices are not applied.
These totals include the estimated labor for each option.
Plan details & review
More project facts 12
Floor path review floor_system slab_slope finished_headroom threshold_transition exterior_landing_condition drainage_path slab_moisture_status vapor_barrier_6mil primer self_leveling_underlayment xps_rigid_foam_board subfloor_tg_osb_23_32 lvp_flooring
Structural shell / site review garage_door_infill_path new_opening_header_path braced_wall_shear_path foundation_slab_edge_status slab_condition_status decay_pest_status site_overlay_status vapor_barrier_6mil primer self_leveling_underlayment xps_rigid_foam_board subfloor_tg_osb_23_32 lvp_flooring lumber_2x6 pt_sill_plate osb_wall_7_16 house_wrap siding_panel anchor_bolt sill_gasket z_flashing polyurethane_caulk
Openings review exterior_door_count window_count egress_window_count egress_opening_sizing egress_sill_height sleeping_zone_served exit_path_status light_ventilation_status separate_entrance property_line_opening_clearance lumber_2x6 pt_sill_plate osb_wall_7_16 house_wrap siding_panel anchor_bolt sill_gasket z_flashing polyurethane_caulk exterior_door_unit window_unit egress_window_unit
MEP trade review adu_scope_mode include_bathroom hvac_strategy panel_capacity sewer_route smoke_co_readiness electrical_service_path sewer_slope_path exhaust_route_status hvac_ventilation_path utility_route_status lumber_2x4 pt_sill_plate lumber_2x6 exterior_door_unit window_unit egress_window_unit bath_exhaust_fan framing_nails exterior_fastener
Energy / envelope review state ceiling_type ceiling_insulation exterior_wall_framing electrical_service_path panel_capacity exhaust_route_status hvac_ventilation_path insulation_batt_r21 ceiling_insulation_r38 ventilation_baffle sound_batt_insulation bath_exhaust_fan
Fire separation review attachment_type shared_wall_length ceiling_type roof_load_change fire_separation_status penetration_protection_status dwelling_unit_separation smoke_co_readiness drywall drywall_type_x_5_8 mold_resistant_drywall cement_board cement_board_screw alkali_mesh_tape waterproof_membrane tile_thinset fire_caulk drywall_screws joint_compound
Planning assumptions
4Material quantities and planning BOM for Garage Conversion / ADU Material Calculator based on selected inputs.
Planning assumptions · 4
- Estimator scope is limited to converting an existing rectangular garage shell. Existing side and rear walls are treated as already built; new framing focuses on the former garage-door opening and simple interior partitions, not a new detached ADU shell, roof, or foundation.
- Existing slab bearing, shell framing, roof / truss dead-load capacity, and threshold transitions are assumed adequate for the selected floor and finish path until field-verified.
- Bathroom plumbing-wall, shower backer, egress window, and bath fan quantities are planning allowances only; plumbing and electrical design, slab trenching, DWV vent routing, fixture-carrier backing, the full exhaust duct / roof-cap package, and permit review remain outside the takeoff.
- Fire-separation quantities use a conservative Type X material takeoff path, not a rated-assembly design or code approval. Final assemblies, required faces, penetrations, and inspection sequence depend on the approved use, locally adopted code, and permit review.
Not included / Trade review
4138 open decisions / checks · 3 estimate boundaries.
-
Open decisions / checks
38- Threshold / door transition still needs review after the selected floor build-up height is known.
- Exterior landing condition is still unknown for the converted entry.
- Drainage path at the converted garage entry is still unknown.
- Slab moisture status is still unknown before finish flooring is selected.
- Egress opening sizing: Egress opening sizing is still unknown.
- Sill height: Sill height is still unknown.
- Sleeping zone: Sleeping-zone egress service is still unknown.
- Exit path: Exterior exit path status is still unknown.
- Light / ventilation: Light / ventilation path is still unknown.
- ADU / conversion zoning path is still unresolved. Confirm local allowance, setbacks, parking, occupancy, address, and utility triggers before treating this as an ADU-ready plan.
- Separate entrance planning is still unresolved. Verify whether the selected layout leaves room for a dedicated exterior entry before export.
- Finished headroom still needs a field check after floor and ceiling build-up are confirmed.
- Fire separation: Fire separation status is still unknown.
- Penetration protection: Penetration protection status is still unknown.
- Dwelling-unit separation: Dwelling-unit separation status is still unknown.
- Smoke / CO readiness: Smoke / CO device locations, interconnection method, and local life-safety triggers are still unknown.
- Electrical service / load path: Panel capacity, load calculation, feeder / subpanel, and service-upgrade path are still unknown.
- Sewer slope / route: Drain / sewer tie-in, slope, vent path, trench, and ejector-pump scope are still unknown.
- Bath / kitchen exhaust: Bath and kitchen exhaust routing is still unknown.
- HVAC / ventilation: Heating / cooling equipment, duct / line-set routing, condensate, combustion-air, and ventilation delivery are still unknown.
- Utility route constraints: Utility route constraints are still unknown.
- Garage-door infill: Garage-door infill path is still unknown.
- New openings / headers: New opening and header path is still unknown.
- Braced-wall / shear path: Braced-wall or shear path is still unknown.
- Foundation / slab edge: Foundation and slab-edge status is still unknown.
- Slab condition: Slab cracks, moisture, flatness, and flood-elevation status are still unknown.
- Termite / decay: Termite and decay status is still unknown.
- Site overlay: WUI, flood, coastal, property-line, and local overlay status is still unknown.
- Jurisdiction source model is unknown; select a state and complete local jurisdiction source review before relying on the BOM.
- Single-story existing garage status still needs field review before using a standard conversion path.
- Garage conversion footprint / rebuild scope is still unknown.
- Prior permit history is still unknown for this garage shell.
- Hillside, flood, liquefaction, or similar hazard-map status is still unknown.
- Roof-load and ceiling structural change status is still unknown.
- Property-line and opening clearance status is still unknown.
- Existing shell eligibility is not fully cleared. Confirm single-story status, no addition / rebuild scope, prior permit history, hazard maps, roof-load changes, and property-line / opening clearance before relying on this as a standard conversion path.
- Floor build-up still needs threshold, exterior landing, drainage, and slab moisture review before the floor package is treated as procurement-ready.
- Where garage use remains, preserve the garage-to-dwelling separation required by the locally adopted code (IRC R302.6). A full conversion may instead be governed by the dwelling-unit or occupancy separation applicable to the approved use. The Type X quantities here are a conservative material allowance only - not a rated-assembly design or code approval. Confirm the required assembly, openings, penetrations, and inspection sequence with the building department before closing framing.
-
Estimate boundaries
3- This is a materials-only BOM subtotal, not an installed ADU project budget.
- Soft costs, contractor labor, design, permits, plan check, inspections, delivery, taxes, utility upgrades, contractor overhead / profit, and site-specific engineering are not included.
- Full MEP design, slab trenching, utility permits, and detached-shell structural retrofit work stay outside this conversion calculator.
How pricing works
Where each price comes from, when it was checked, and what the formulas assume.
- Source: Retailer price
- Region: Calculator default pricing
- Price as of: 06/01/2026 – 08/09/2026
- This price basis is a materials-only BOM subtotal; installed project budget is not estimated.
- Priced-line coverage means the selected material rows have pricing; ADU feasibility, permit, utility, and trade review still decide whether this conversion is actionable.
Contractor handoff
Contractor handoff pack
Share this project snapshot, field evidence, open checks, and contractor questions before requesting an installed quote.
- Project snapshot: 20 ft x 20 ft shell, 8 ft ceiling, 7 ft 9 in remaining after modeled floor build-up; ceiling drops, ducts, and soffits not deducted. 1 exterior door(s), 2 window(s), 1 egress window(s), 16 ft x 7 ft garage opening. Materials-only BOM subtotal; 44 priced lines / 44 total lines; installed ADU project budget excluded.
- Photos checklist: garage door infill area, all walls and ceiling, slab cracks / moisture clues, panel location, sewer tie-in path, exterior landing / drainage, windows, doors, and any penetrations.
- Utility / site snapshot: Panel capacity still unconfirmed; Drain / sewer route still undecided; Slab condition still unknown; Slab moisture status still unknown; Drainage path still needs review; Property-line / opening clearance still unknown.
- Open checks: 38 actionable decisions or field checks are listed under "Not included / Trade review"; hand that list to the contractor.
- Ask contractor which local planning, permit, energy / Title 24, and inspection steps apply before pricing construction. Ask contractor to confirm HVAC, electrical panel capacity, sewer route, smoke / CO, and kitchenette / bath MEP scope. Ask contractor to confirm threshold, exterior landing, drainage, slab moisture, and property-line / opening clearance before ordering.
Permit & planning reference
Planning education
Background reading on permits, energy, soft costs, and planning boundaries - open it when you need the detail.
Educational summary only - explanatory context that does not change the active BOM, pricing, or permit status. It is not code or permit approval, professional MEP design, an installed quote, a contractor estimate, or legal advice. Verify every item with your local building department.
Permit, energy & inspection roadmap
Prepare permit-intake deliverables and inspection milestone questions before treating the contractor handoff as quote-ready.
- Local code / zoning: Confirm ADU use, parking / access, setbacks / overlays, address and utility triggers, and the locally adopted code path for the 20 ft x 20 ft shell.
- Plan set: Show the existing shell, proposed use and layout, entry / egress, openings, floor and ceiling sections, garage-door infill, fire separation, and utility routes.
- Energy / ventilation documents: Confirm Title 24 / IECC forms, insulation and air-sealing notes, whole-dwelling ventilation, equipment sizing, and any HERS / testing paperwork required locally.
- Structural / MEP rough inspections: Coordinate framing, headers / bracing, electrical load and panel path, plumbing fixtures and sewer / vent route, HVAC / exhaust, condensate, smoke / CO, and utility routing before cover.
- Insulation / firestop / drywall inspections: Confirm insulation and air sealing, rated separation and penetrations, Type X / moisture-resistant board locations, fasteners, and wet-area transitions before closing assemblies.
- Final closeout: Confirm egress, landing and drainage, life-safety devices, fixtures, ventilation controls, finishes, address / utility requirements, required test reports, and final approvals.
- Planning-level checklist only; not permit approval, code approval, stamped drawings, plan-check acceptance, or inspection signoff.
Scenario comparison
Compare common Garage ADU intents across MEP, egress, storage, and BOM boundary before treating one preset as the active project path.
- Straight studio ADU — MEP: compact bath, kitchenette review if added, heat-pump / ventilation path, panel capacity, sewer route, and smoke / CO coordination. Egress: single egress-capable sleeping / living opening plus dedicated entry and exit path review. Storage: minimal owner storage; prioritize bed / living clear zone and utility access. BOM boundary: planning materials only; ADU dwelling readiness still depends on local review and trade scope.
- Rental-ready compact ADU — MEP: kitchenette, bath, HVAC, electrical, sewer, exhaust, smoke / CO, and energy-review coordination stay review-first. Egress: two egress windows in the preset plus primary entrance, landing, sill, and exit-path review. Storage: rental storage, appliance clearances, cleaning closet, and utility access need layout confirmation. BOM boundary: adds review-only kitchenette / entrance / MEP lines but still excludes installed budget, labor, permits, and utility upgrades.
- Family guest suite — MEP: compact bath and comfort HVAC path for guest use, with kitchenette optional and still review-dependent. Egress: guest sleeping / living clear zone needs egress opening, entry, and light / ventilation review. Storage: guest storage, linens, luggage, and privacy / acoustic separation should be planned before handoff. BOM boundary: useful for guest-suite materials, but not a complete rental-ready ADU package or permit approval.
- Flex room not ADU — MEP: No kitchenette or bath dwelling package; keep HVAC / electrical / smoke-CO review proportional to a flex room. Egress: do not assume sleeping occupancy; keep entry, window, and exit-path review tied to the claimed use. Storage: can preserve garage / household storage better than ADU scenarios, but parking and lifestyle tradeoffs remain owner decisions. BOM boundary: not an ADU dwelling; use this as flex-room material planning, not a rental-ready ADU scope.
Soft-cost / timeline education
Design, permit, inspection, utility upgrade, labor, overhead / profit, tax / delivery, and timeline items are education-only context outside the materials-only BOM.
- Professional / permit / installed costs: Design and measured plans, engineering, permit and inspection fees, labor, contractor overhead / profit, tax, delivery, haul-off, and staging stay outside the materials-only BOM.
- Utilities / hidden conditions: Panel, feeder, sewer, water, gas, condensate, meter, service upgrades, concealed damage, and site constraints require trade and field review.
- Project timeline: Design, plan check, corrections, procurement, inspection windows, trade sequencing, and utility coordination determine the schedule; this calculator makes no timeline commitment.
Compare scenarios
Ready for a permit-aware quote?
Send this scope to ADU-experienced contractors near you. Feasibility areas marked "Needs review" are flagged in the contractor handoff.
Material list
Your build list
Each line shows a purchase quantity, a coverage amount, or a planning allowance - the line says which. Check pack sizes and your site conditions before you order.
| Material | Assembly | Unit | Qty | Unit price | Total | Source |
|---|---|---|---|---|---|---|
|
6 mil vapor barrier rolls
200 sq ft roll | Polyethylene
Floor path review: Depends on slab slope, finished headroom, threshold, landing, drainage, and slab moisture readiness.Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review. |
slab prep and floor build-up | roll |
3
|
$27.49 |
$82.47 |
Shopping-ready
Retailer price 06/05/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Floor primer gallons
1 gal | Primer
Floor path review: Depends on slab slope, finished headroom, threshold, landing, drainage, and slab moisture readiness.Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review. |
slab prep and floor build-up | gallon |
2
|
$44.39 |
$88.78 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Self-leveling underlayment bags
Note: Average fill assumes the slab slope is corrected across the floor build-up, not that the full low point is filled everywhere.50 lb bag | Cementitious Underlayment | 50 lb bag
Floor path review: Depends on slab slope, finished headroom, threshold, landing, drainage, and slab moisture readiness.Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review. |
slab prep and floor build-up | bag |
26
|
$42.94 |
$1,116.44 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
1 in XPS rigid-foam boards
4 ft x 8 ft x 1 in | Rigid FoamActual 1 in thick
Floor path review: Depends on slab slope, finished headroom, threshold, landing, drainage, and slab moisture readiness.Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review. |
slab prep and floor build-up | board |
14
|
$32.38 |
$453.32 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
23/32 in T&G OSB subfloor
4 ft x 8 ft | Subfloor PanelActual 0.72 in thick
Floor path review: Depends on slab slope, finished headroom, threshold, landing, drainage, and slab moisture readiness.Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review. |
slab prep and floor build-up | sheet |
14
|
$20.48 |
$286.72 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Luxury vinyl plank cartons
20 sq ft carton | Finish Flooring
Floor path review: Depends on slab slope, finished headroom, threshold, landing, drainage, and slab moisture readiness.Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review. |
slab prep and floor build-up | carton |
23
covers 432 sq ft
|
$65.82Not editable: priced as a package | $1,513.86 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
2x6 framing lumber
2x6 | Stock 8 ft | Spruce Pine FirActual 1.5 in thick x 5.5 in wide
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | board |
27
|
$5.55 |
$149.85 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
2x6 framing lumber
2x6 | Stock 16 ft | Spruce Pine FirActual 1.5 in thick x 5.5 in wide
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | board |
2
|
$7.98 |
$15.96 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
PT 2x6 bottom plates
2x6 | Stock 16 ft | Pressure TreatedActual 1.5 in thick x 5.5 in wide
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | board |
2
|
$22.98 |
$45.96 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Double 2x6 headers
Note: Modeled as simple front-elevation opening headers inside the new front wall, not a replacement for the original garage-door header.2x6 | Stock 8 ft | Spruce Pine FirActual 1.5 in thick x 5.5 in wide
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | board |
3
|
$5.55 |
$16.65 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
7/16 in OSB wall sheathing
4 ft x 8 ft | OsbActual 0.44 in thick
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | sheet |
3
|
$9.72 |
$29.16 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
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|
House wrap
495 sq ft roll | Weather Barrier
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | roll |
1
|
$109.00 |
$109.00 |
Shopping-ready
Retailer price 06/05/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
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|
Exterior siding panels
4 ft x 8 ft panel | Cladding
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | sheet |
3
|
$45.98 |
$137.94 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
1/2 in mechanical concrete anchors
Note: Modeled as retrofit anchoring for the new front wall at the former garage-door opening rather than cast-in-place foundation bolts.1/2 in x 5-1/2 in | Steel
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | bolt |
4
|
$4.39 |
$17.56 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is an installed or coverage basis, not a package count. Convert it to supplier pack sizes.
|
||||||
|
Sill gasket rolls
50 ft roll | Foam Seal
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | roll |
1
covers 16.8 linear ft
|
$7.84Not editable: priced as a package | $7.84 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Z-flashing sections
10 ft piece | Flashing
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | piece |
2
|
$7.98 |
$15.96 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Exterior polyurethane sealant tubes
10 oz tube | Sealant
Structural shell / site review: Depends on garage-door infill, new openings / headers, bracing, foundation / slab edge, slab condition, decay, and site overlay review.Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review. |
new front wall and openings | tube |
2
|
$8.47 |
$16.94 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
2x4 framing lumber
2x4 | Stock 10 ft | Spruce Pine FirActual 1.5 in thick x 3.5 in wide
MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
interior partitions and bathroom walls | board |
7
|
$4.98 |
$34.86 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
2x4 framing lumber
2x4 | Stock 8 ft | Spruce Pine FirActual 1.5 in thick x 3.5 in wide
MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
interior partitions and bathroom walls | board |
1
|
$3.65 |
$3.65 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
PT 2x4 bottom plates
2x4 | Stock 8 ft | Pressure TreatedActual 1.5 in thick x 3.5 in wide
MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
interior partitions and bathroom walls | board |
1
|
$4.58 |
$4.58 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
2x6 framing lumber
2x6 | Stock 10 ft | Spruce Pine FirActual 1.5 in thick x 5.5 in wide
MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
interior partitions and bathroom walls | board |
11
|
$5.55 |
$61.05 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
2x6 framing lumber
2x6 | Stock 10 ft | Spruce Pine FirActual 1.5 in thick x 5.5 in wide
MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
interior partitions and bathroom walls | board |
3
|
$7.98 |
$23.94 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
PT 2x6 bottom plates
2x6 | Stock 10 ft | Pressure TreatedActual 1.5 in thick x 5.5 in wide
MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
interior partitions and bathroom walls | board |
2
|
$22.98 |
$45.96 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
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|
R-21 batt insulation
23 in cavity batt | Fiberglass Batt
Energy / envelope review: Title 24 / IECC energy review depends on insulation, air sealing, whole-dwelling ventilation, HERS / inspection deliverables, and heat-pump readiness. |
insulation and air sealing | bag |
6
|
$125.10 |
$750.60 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
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R-38 ceiling insulation
Note: Vented-attic paths should still confirm baffles and vent continuity in field review.attic batt / blown coverage pack | Ceiling Insulation
Energy / envelope review: Title 24 / IECC energy review depends on insulation, air sealing, whole-dwelling ventilation, HERS / inspection deliverables, and heat-pump readiness. |
insulation and air sealing | bag |
4
|
$67.58 |
$270.32 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
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Attic ventilation baffles
22 in x 48 in baffle | Attic Ventilation
Energy / envelope review: Title 24 / IECC energy review depends on insulation, air sealing, whole-dwelling ventilation, HERS / inspection deliverables, and heat-pump readiness. |
insulation and air sealing | carton |
4
covers 32 baffle
|
$45.80Not editable: priced as a package | $183.20 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is an installed or coverage basis, not a package count. Convert it to supplier pack sizes.
|
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Sound batt insulation
sound-control batt pack | Sound Batt
Energy / envelope review: Title 24 / IECC energy review depends on insulation, air sealing, whole-dwelling ventilation, HERS / inspection deliverables, and heat-pump readiness. |
insulation and air sealing | bag |
3
covers 168 sq ft
|
$83.98Not editable: priced as a package | $251.94 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
1/2 in drywall sheets
4 ft x 8 ft | Gypsum BoardActual 0.5 in thick
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | sheet |
15
|
$12.98 |
$194.70 |
Shopping-ready
Retailer price 06/05/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
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5/8 in Type X drywall sheets
4 ft x 8 ft | Gypsum BoardActual 0.63 in thick
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | sheet |
25
|
$14.48 |
$362.00 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
1/2 in mold-resistant drywall
4 ft x 8 ft | Gypsum BoardActual 0.5 in thick
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | sheet |
1
|
$15.98 |
$15.98 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
1/2 in cement board panels
3 ft x 5 ft | Cement BackerActual 0.5 in thick
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | sheet |
5
|
$15.41 |
$77.05 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Cement-board screw boxes
box | Fastener
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | box |
1
|
$34.98 |
$34.98 | |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Alkali-resistant mesh tape rolls
roll | Tile Backer Accessory
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | roll |
2
|
$8.94 |
$17.88 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Waterproof membrane rolls
54 sq ft roll | Waterproofing
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | roll |
2
covers 63 sq ft
|
$123.95Not editable: priced as a package | $247.90 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Modified thinset bags
50 lb bag | Thinset | 50 lb bag
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | bag |
1
|
$17.98 |
$17.98 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Fire-rated sealant tubes
10 oz tube | Sealant
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | case |
1
covers 8 tube
|
$171.36Not editable: priced as a package | $171.36 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Drywall screw boxes
5 lb box | Fastener
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | box |
3
|
$24.98 |
$74.94 |
Shopping-ready
Retailer price 06/05/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Joint compound buckets
4.5 gal bucket | Drywall Finish
Fire separation review: Depends on attached fire separation, shared-wall penetrations, ceiling path, dwelling-unit separation, smoke / CO, and local inspection details. |
drywall and fire separation | bucket |
4
|
$22.93 |
$91.72 |
Shopping-ready
Retailer price 06/05/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Prehung exterior door units
3-0 x 6-8 | Door Unit
Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review.MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
finish materials and ventilation | door |
1
|
$429.00 |
$429.00 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is an installed or coverage basis, not a package count. Convert it to supplier pack sizes.
|
||||||
|
Vinyl window units
3050 window | Window Unit
Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review.MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
finish materials and ventilation | window |
1
|
$289.00 |
$289.00 |
Shopping-ready
Retailer price 06/01/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is an installed or coverage basis, not a package count. Convert it to supplier pack sizes.
|
||||||
|
Egress-capable window units
3050 egress window | Egress Window Unit
Openings review: Depends on entry, egress opening count / sizing, sill height, exit path, and property-line / opening-clearance review.MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
finish materials and ventilation | window |
1
|
$483.00 |
$483.00 |
Shopping-ready
Retailer price 06/05/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is an installed or coverage basis, not a package count. Convert it to supplier pack sizes.
|
||||||
|
Bathroom exhaust fans
Note: Duct, roof cap, and electrical branch details remain outside this first conversion calculator.80 CFM fan | Ventilation
MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination.Energy / envelope review: Title 24 / IECC energy review depends on insulation, air sealing, whole-dwelling ventilation, HERS / inspection deliverables, and heat-pump readiness. |
finish materials and ventilation | fan |
1
|
$139.00 |
$139.00 | |
Quantity basis The visible row quantity is an installed or coverage basis, not a package count. Convert it to supplier pack sizes.
|
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|
Framing nail boxes
box | Fastener
MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
finish materials and ventilation | box |
1
|
$57.28 |
$57.28 |
Shopping-ready
Retailer price 06/05/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
|
Exterior fastener boxes
box | Fastener
MEP trade review: Depends on kitchenette, bath, electrical service, sewer slope, exhaust routing, HVAC / ventilation, utility routes, smoke / CO, and energy-review coordination. |
finish materials and ventilation | box |
1
|
$11.97 |
$11.97 |
Shopping-ready
Retailer price 06/05/2026 — price may have changed - verify before ordering Home Depot |
Quantity basis The visible row quantity is a purchase or ordering quantity.
|
||||||
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Estimated materials total$8,450.25
Project material guide
2026 U.S. Garage Conversion / ADU Planning Guide
Switch between tabs to compare nominal sizes, actual sizes, common uses, and planning rules for this project.
Garage Floor Build-Up Paths
Garage slabs often slope toward the old overhead door. This calculator treats floor build-up as a directional path selection, not a finish-tolerance guarantee, and it automatically shifts steep self-leveler paths toward sleepers.
| Path | Typical layers | Use case | Planning note |
|---|---|---|---|
| Direct LVP | Moisture prep + thin underlayment + LVP | Flatter slabs with minimal build-up | Keep an eye on slab flatness, moisture, and local finish-floor requirements before buying direct-attach flooring. |
| Self-leveler + XPS | Primer + self-leveler + 6 mil vapor barrier + XPS + 23/32 T&G subfloor + LVP | Cold slabs or conversions that need a more comfortable insulated floor | This calculator keeps this path in the minor-correction band and shifts steeper slabs toward sleepers. |
| Sleeper subfloor | 6 mil vapor barrier + PT sleepers + insulated cavity + 23/32 T&G subfloor + adhesive + LVP | More severe slab slope or stronger raised-floor preference | This path needs mechanical anchoring and eats headroom, so confirm thresholds and clear ceiling height before committing. |
New Front Wall and Partition Framing
The calculator assumes the garage shell already exists. New framing scope is concentrated at the former garage opening, bathroom plumbing-wall partitions, and limited interior layout work.
| Assembly | Common stock | Actual size | Planning rule |
|---|---|---|---|
| New front wall | 2x4 or 2x6 framing lumber | 1.5" x 3.5" or 1.5" x 5.5" | Use the selected exterior-wall framing size for the new wall at the former garage opening, then verify mechanical anchoring, flashing, and sealant details at the slab transition. |
| Bottom plates on slab | Pressure-treated 2x4 or 2x6 | 1.5" x 3.5" or 1.5" x 5.5" | Any framing bearing directly on concrete stays on a treated bottom-plate path in this calculator. |
| Dry partitions | 2x4 framing lumber | 1.5" x 3.5" | Dry interior partitions stay on a simple 2x4 planning path. |
| Bathroom plumbing wall | 2x6 framing lumber | 1.5" x 5.5" | Bathroom plumbing framing is modeled as a dedicated 2x6 wall rather than a generic 2x4 partition. |
| Opening headers | Double 2x6 | 3.0" x 5.5" built-up header | This is a conservative planning allowance for door / window openings cut into the new front wall only. |
Insulation and Air-Sealing Rules
This calculator separates shell insulation from attached-conversion fire / sound separation so the user can see what belongs to comfort, fire separation, and venting scope.
| Assembly | Typical product | Planning basis | Common note |
|---|---|---|---|
| Exterior shell walls | R-13 batt for 2x4 or R-21 batt for 2x6 | Shell exterior wall area | Actual code-required R-values vary by climate zone and local energy rules. |
| Vented attic ceiling | R-30 / R-38 / R-49 attic insulation + baffles | Ceiling area | Vented attic paths should still verify baffles and ventilation continuity outside this calculator. |
| Vaulted / low-cavity ceiling | Closed-cell spray foam | Ceiling area x target thickness | Vaulted paths are modeled with spray foam rather than batt packs because cavity depth and vent strategy change quickly. |
| Attached shared wall | Sound batt / mineral-wool style batt | Shared wall area | Modeled separately from exterior wall insulation to keep the fire-separation scope visible. |
| Sleeper floor path | Floor cavity batt | Raised floor area | Only the sleeper-subfloor path gets cavity insulation in this first release. |
Drywall and Fire Separation
Attached conversions frequently need a stricter wall / ceiling separation path than detached conversions. This calculator keeps that distinction explicit and separates shower-wall backer accessories from generic drywall takeoff.
| Board type | Typical size | Use case | Planning note |
|---|---|---|---|
| 5/8 in Type X drywall | 4 ft x 8 ft sheets | Shared wall and attached-conversion ceiling separation path | Modeled as a conservative attached-conversion planning path, then left for local fire / ADU review. |
| 1/2 in standard drywall | 4 ft x 8 ft sheets | General dry walls and detached ceilings | Used for standard shell and partition finish areas that are not shower-wall or fire-separation scope. |
| 1/2 in mold-resistant drywall | 4 ft x 8 ft sheets | Bathroom / shower-wall areas outside the shower | Kept separate from standard drywall so the BOM shows the wet-area upgrade explicitly. |
| 1/2 in cement board | 3 ft x 5 ft panels | Shower wall allowance | Used only for the shower / backer subset of shower-wall area, with separate screws, mesh tape, waterproofing, and thinset allowances. |
Openings and Ventilation
- Exterior door allowance: Modeled as a common prehung exterior door package on the new front wall.
- Window allowance: Window counts represent planning allowances, not final fenestration schedules or elevation layouts.
- Egress window rule: Sleeping-room conversions should verify at least one IRC R310 emergency escape opening; grade-floor egress windows are commonly allowed at 5.0 sq ft net clear with 20 in minimum width, 24 in minimum height, and a sill no more than 44 in above the finished floor.
- Front-wall transition detailing: The new front wall scope includes a directional flashing / sealant allowance, but not a full permit-detail set for slab cracks, WRB sequencing, or cladding manufacturer details.
- Bathroom ventilation: A bathroom path adds one bath exhaust fan allowance, but not the full duct / roof cap package.
What This Calculator Covers
- Covered: Floor build-up, new front-wall framing, insulation, drywall / fire separation, openings, bathroom wall finish scope, and directional pricing.
- Not covered: Full MEP rough-in, HVAC sizing, structural retrofit, slab trenching design, engineered shear / moment design, permit package, and energy code compliance package.
- Estimator stance: Use this as a pre-quote / planning BOM for an existing garage shell, then hand the project to local design, permit, and trade-specific review after field-verifying slab, shell, and roof conditions.
This calculator treats the garage shell as an existing rectangular enclosure and focuses on the conversion scope: front infill framing, interior partitions, floor build-up, insulation, drywall / fire separation, openings, and directional pricing. It is a planning BOM, not a permit set, structural retrofit package, or full MEP design.
Details to confirm
38 open review items
400 sq ft floor build-up, 1040 sq ft insulated shell, and 46 finish-board sheets for a 20 ft x 20 ft garage conversion / ADU
Can I proceed?
You can read the plan now - the answers below sharpen it
Top blocker
Garage conversion details still to confirm
What blocks me?
41 review items before handoff
Missing info
Threshold / door transition still needs review after the selected floor build-up height is known.
What this BOM includes / excludes
Materials-only BOM subtotal; installed budget excluded
Next contractor questions
Ask contractor which local planning, permit, energy / Title 24, and inspection steps apply before pricing construction. Ask contractor to confirm HVAC, electrical panel capacity, sewer route, smoke / CO, and kitchenette / bath MEP scope. Ask contractor to confirm threshold, exterior landing, drainage, slab moisture, and property-line / opening clearance before ordering.
Estimated materials total