# Room addition takeoff

> 16′ × 12′ addition: 4.75 cu yd of concrete, 63 studs, 28 sheets of sheathing, 3 squares of roofing and 14 sheets of drywall. For builders: the takeoff for a room addition — excavation, foundation, framing, roof, windows, siding, insulation by zone and drywall, with the permits and inspections.

## What to buy (16′ × 12′ addition)

Every line shows the quantity to buy and how StudSheet got it: the spacing, the waste and the package size, so you can check it before the supply house or the quote.

| Buy | Material | How StudSheet counts it | What it is for |
|---|---|---|---|
| **1 survey** | Survey or plot plan (boundary and the new footprint) | Zoning (setbacks, lot coverage, height) and the permit office work from it, and it places the footings. | Shows the lot lines, setbacks and the new footprint: zoning and the permit office ask for it, and it places the footings. |
| **1 set** | Plans and engineering (drawings, engineering, energy forms) | Architect or designer drawings, the engineer’s foundation and beam details, and the energy compliance for zone 4. | Drawings by an architect or designer, the engineer’s foundation, beam and connection details, and the energy forms the permit asks for. |
| **1 permit** | Building permit and plan review (with plan review and inspections) | An addition needs a construction permit from your town’s construction office, usually with drawings sealed by a licensed architect or engineer, and zoning first (setbacks, lot coverage, height). Plan review takes weeks. The electrical, plumbing and HVAC work goes on the licensed trades’ own permits. | Set by your building department — often by area, volume or the job’s value. The inspections usually come with it. |
| **1 haul** | Dumpster (20-yard roll-off) | Framing offcuts, packaging, roofing and drywall scraps, and the old siding along the house: about one 20-yard haul per 400 sq ft of new floor. Spoil from the dig goes by truck, not in the dumpster. The dig: about 25.3 cu yd out, 11.2 cu yd back in as backfill, ≈17.7 cu yd loose to truck away (25% swell). | Construction debris container, priced per haul. Some towns want a permit to park it on the street. |
| **1.5 cu yd (one pour)** | Ready-mix concrete (delivered) (16″ × 8″ continuous footing, strength per the plans (psi)) | 40′ of footing × 16″ wide × 8″ thick = 1.32 cu yd, + 10% for the trench’s uneven bottom = 1.45 cu yd, ordered up to the next quarter. The IRC asks at least 12″ × 6″, projecting 2″ or more past the wall and no more than its thickness (R403.1.1); Table R403.1(1) sets the width for your soil, stories and snow load. | Ordered by the cubic yard (by the cubic metre in Canada) from a local plant; the truck chutes it into the forms. |
| **5 bars** | Rebar #4 (½″) (#4 × 20′) | Two continuous #4 bars in the footing (80 ft + 10% for laps and corners). Required in seismic areas and common everywhere — follow the plans. | Grade 40 or 60 steel bar for driveway grids and footings. 10 ft bars fit in a car; 20 ft bars mean fewer laps. |
| **20 dobies** | Rebar chairs or dobies (3″ dobies) | One every 4 ft under each bar: steel cast against the ground needs 3″ of concrete under it (ACI 318). | Plastic chairs or small concrete blocks that hold mesh or rebar at the right height while you pour. |
| **3.25 cu yd (one pour)** | Ready-mix concrete (delivered) (8″ poured wall, 3′ tall, strength per the plans (psi)) | 40′ × 8″ × 3′ = 2.96 cu yd, + 5% = 3.11 cu yd. Forms by the foundation crew or rented panels. Top of wall 8″ above finished grade (IRC R404.1.6 asks 6″ or more). | Ordered by the cubic yard (by the cubic metre in Canada) from a local plant; the truck chutes it into the forms. |
| **10 bolts** | Anchor bolts ½″ × 10″, nut and washer (½″ × 10″ J-bolts) | Set in the wet concrete (or grouted cores) under the sill: ½″ bolts, 7″ into the concrete, no more than 6 ft apart, at least two per plate piece with one within 12″ of each end (IRC R403.1.6). High-wind and seismic areas add plate washers and hold-downs per the plans. | J-bolts set in the wet concrete (or grouted block cores) to hold the sill or bottom plate down. |
| **1 pail** | Foundation dampproofing, 5-gal pail (5-gal, about 125 sq ft a pail) | 93 sq ft of wall below grade (40′ × 2′ 4″), from the footing to the finished grade (IRC R406). | Asphalt coating on the outside of below-grade walls, from the footing up to the finished grade. |
| **1 roll** | Rebar tie wire (16-gauge roll) | Ties the bar laps, the corners and the mesh laps. | 16-gauge annealed wire that ties bars where they cross and laps together. |
| **203 sq ft** | Polyethylene sheeting (vapor retarder) (Class I, laps 6″, taped) | 166 sq ft of crawlspace ground + 10% for laps, plus 6″ up the walls. IRC R408 (the vented exception and the sealed crawlspace both start here). | Class I poly over crawlspace ground, seams lapped and taped — and in Canada the warm-side vapour barrier on walls and ceilings. |
| **3 vents** | Foundation vent 8″ × 16″ (8″ × 16″, about 45 sq in free area) | One within 3 ft of each outside corner (2) plus one more for cross-flow; with the ground covered by a Class I vapor retarder the vents may total 1/1,500 of the crawlspace (IRC R408.2). | Set in the crawlspace wall; one near each outside corner. |
| **1 door** | Crawlspace access door (16″ × 24″ or larger) | Access to the crawlspace: at least 16″ × 24″ through the wall or 18″ × 24″ through the floor (IRC R408.4). | At least 16″ × 24″ through the wall (or 18″ × 24″ through the floor). |
| **1 roll** | Sill sealer gasket, 5½″ × 50 ft (5½″ × 50′ roll) | 40 ft of sill, 50 ft a roll. | Foam strip under the sill plate: stops air leaks between the wood and the concrete. |
| **2 boards** | Pressure-treated 2×6 (treated 2×6 × 12′) | Pressure-treated sill on the gasket, bolted down; one piece per wall up to 16 ft (wood on concrete must be treated, IRC R317.1; R304 in the 2024 IRC). | Treated against rot — for wood touching concrete or outdoors. |
| **1 board** | Pressure-treated 2×6 (treated 2×6 × 16′) | Pressure-treated sill on the gasket, bolted down; one piece per wall up to 16 ft (wood on concrete must be treated, IRC R317.1; R304 in the 2024 IRC). | Treated against rot — for wood touching concrete or outdoors. |
| **13 joists** | 2×10 framing lumber (2×10 × 12′) | 13 joists at 16″ on center along 16′, running out from the house, about 11′ 4″ clear. Check the size against IRC Table R502.3.1(2) for your species and grade, or have the engineer add a girder to cut the span. | Actually 1½″ × 9¼″. Joists, rafters, rims and ledgers. |
| **2 boards** | 2×10 framing lumber (2×10 × 16′) | 16 ft of rim + 5%, in 16 ft boards. | Actually 1½″ × 9¼″. Joists, rafters, rims and ledgers. |
| **1 board** | 2×10 framing lumber (2×10 × 16′) | Along the house’s band joist (16′), with the siding off and flashed above. The house’s framing must carry it and the engineer sets the fastening. | Actually 1½″ × 9¼″. Joists, rafters, rims and ledgers. |
| **26 screws (about)** | Structural ledger screws (per the engineer’s schedule) | Two every 16″ along the ledger is a common pattern; use the engineer’s. | Code-listed screws made for deck ledgers (for example FastenMaster LedgerLOK). Spacing comes from the maker’s chart. |
| **13 hangers** | Joist hangers (for 2×10) | One per joist at the ledger. | Galvanized (G185) or stainless brackets that hold each joist on the ledger or beam. Sized to the joist; fill every nail hole. |
| **2 boxes** | Joist hanger nails (10d × 1½″) (10d × 1½″, 1 lb box) | About 10–12 nails per hanger; every hole filled. | The short, thick nails hangers are rated with — not framing nails. |
| **7 sheets** | Subfloor ¾″ tongue-and-groove, 4×8 (23/32″ T&G, 4×8) | 192 sq ft + 8% for cuts ÷ 32 sq ft a sheet, long edges across the joists. | 23/32″ OSB or plywood subfloor panel, glued and screwed or ring-nailed to the joists. |
| **4 tubes** | Subfloor adhesive, 28 oz tube (28 oz tubes) | About 36 ft of ¼″ bead per sheet (every joist and the groove), about 80 ft a tube. | A bead on every joist and in the groove: a stiff, quiet floor. |
| **63 studs** | 2×6 (2×6 × 92-5/8″ precut) | Layout 33 (40′ of wall at 16″ on center, one at each end of each wall) + 4 at the corners + 16 kings and jacks at 4 openings + 4 at the opening into the house = 57, + 10% for crooked boards. Studs in the openings become cripples. 92-5/8″ precuts make a 8′ 1-1/8″ wall with a bottom plate and a double top plate. | Framing lumber, actually 1½″ × 5½″. |
| **6 boards** | 2×6 (2×6 × 12′) | A bottom plate and a double top plate, top-plate joints lapped 24″ or more (IRC R602.3.2). | Framing lumber, actually 1½″ × 5½″. |
| **3 boards** | 2×6 (2×6 × 16′) | A bottom plate and a double top plate, top-plate joints lapped 24″ or more (IRC R602.3.2). | Framing lumber, actually 1½″ × 5½″. |
| **4 headers** | Header stock (built-up 2× or LVL) (size per IRC Table R602.7(1) or (2) or the engineer) | 3 windows (36″ rough openings), 1 door. Outside walls carry the roof, so each header is sized for its span and load: confirm every one. | One per opening in the outside walls. Size each from the IRC header tables or the engineer’s plans. |
| **1 header + temporary shoring** | Header for the opening into the house (sized by the engineer, for a 36″ opening) | The house wall usually carries a floor or the roof: the engineer sizes the header (or beam), its posts and what they bear on. Shore the house before you cut. | Usually an LVL or steel beam sized by the engineer: the house wall often carries a floor or the roof. |
| **12 sheets** | Wall sheathing 7/16″ OSB, 4×8 | 40′ of outside wall × 8′ 11-1/8″ (walls and floor bands) + 32 sq ft of gable = 389 sq ft, − 67 sq ft of openings, + 10% for cuts ÷ 32 sq ft a sheet. Nailed 6″ on the edges, 12″ in the field, or as the bracing plan says (IRC R602.10). | Structural panel on the outside of the studs; it also braces the walls. |
| **5 trusses** | Roof truss (ordered) (common 6/12 × 16′ span, 12″ heels) | 7 trusses at 24″ on center along 12′, 2 of them gable ends. The truss maker designs them for your span, pitch, overhang and snow load (IRC R802.10, ANSI/TPI 1) and sends the drawings and bracing plan with the delivery. | Designed and built by the truss maker for your span, pitch, overhang and loads; the design drawings come with the delivery. |
| **2 trusses** | Gable-end truss (ordered) (gable end × 16′ span) | One at the far wall and one at the house wall, with vertical studs for the sheathing. | End truss with vertical studs for the sheathing; dropped for outlookers when the rake overhangs. |
| **14 ties** | Hurricane ties (truss or rafter to plate) (model per the truss drawings or the uplift table) | One at each end of every truss where it sits on a wall (uplift: IRC R802.11). | Hold the roof down against wind uplift; the truss drawings or the code’s uplift table pick the model. |
| **9 sheets** | Roof sheathing ½″, 4×8 (½″, 4×8, with clips at 24″) | 262 sq ft of roof (234 sq ft in plan with the overhangs × 1.118 for the 6/12 slope) + 10% for cuts ÷ 32 sq ft. | Plywood or OSB rated for the rafter or truss spacing; edge clips between framing at 24″. |
| **1 box (≈688 nails)** | Framing nails 3¼″ (16d), box of 2,500 (3¼″ × .131, coil or stick) | About 8 nails per framing piece (86 studs, plate boards, joists and roof members), per the fastening schedule (IRC Table R602.3(1)). | For the framing nailer: walls, floors, roof framing. |
| **1 box (≈1,960 nails)** | Sheathing nails 2⅜″ (8d), box of 2,500 (2⅜″ × .113 (8d)) | About 70 per sheet at 6″ on the edges and 12″ in the field: 28 sheets. | Wall and roof sheathing: 6″ apart on the edges, 12″ in the field (or as the plans say). |
| **9 bundles (3 squares)** | Architectural shingles (laminated) (3 bundles a square) | 262 sq ft of roof + 10% waste (gable) = 2.88 squares × 3 bundles. | Two-layer asphalt shingles; most cover a square (100 sq ft) with 3 bundles — read the wrapper. |
| **1 bundle** | Starter strip shingles (about 100 ft a bundle) | 26 ft of eaves. | The first course at the eaves and rakes: its sealant strip holds the edge of the first shingles down in wind. |
| **1 bundle** | Hip and ridge cap shingles (about 25 ft a bundle) | 13 ft of ridge. | Pre-bent caps for the ridge and hips; about 25–33 ft a bundle by brand. |
| **1 roll** | Synthetic roof underlayment (10 squares a roll) | 262 sq ft + 10% for laps ÷ 1000 sq ft. | Woven, tear-resistant underlayment that replaced felt; 10-square rolls, fastened with cap nails. |
| **5 pieces** | Drip edge (10 ft pieces) | 26 ft of eaves + 20 ft of rakes + 5% for laps (drip edge at eaves and rakes, IRC R905.2.8.5). | Metal edge at the eaves and rakes that throws water clear of the fascia. |
| **1 box** | Roofing nails, coil (1¼″ coil, box of 7,200) | Four nails per shingle, about 320 a square: ≈921. | Galvanized roofing nails for a coil roofing nailer; long enough to go ¾″ into the deck or through it. |
| **51 pieces** | Step flashing (5″ × 7″ pieces (or as your shingles ask)) | One per shingle course (5″) up both slopes where they meet the house wall: 20′ 1-1/2″. The house’s wrap and siding lap over them. | Bent metal pieces woven in with each shingle course where a roof meets a wall. |
| **2 kick-outs** | Kick-out flashing (left and right) | At the bottom of each roof-to-wall line, so water goes into the gutter, not behind the siding. | Turns water out into the gutter at the bottom of a roof-to-wall joint so it can’t run behind the siding. |
| **3 sections** | Shingle-over ridge vent (4 ft sections) | Along the ridge, stopping about 12″ from each end, with vented soffits for the intake — attic venting (IRC R806). | Vent along the ridge, covered with cap shingles; the label gives its net free area per foot. |
| **12 baffles** | Attic baffles (rafter vents) (one per bay at each eave) | Keep the attic insulation off the soffit vents: 12 bays. | Keep blown insulation from blocking the soffit vents: one per bay at each eave. |
| **1 roll** | House wrap, 9 ft × 150 ft roll | 389 sq ft of wall + 15% for laps ÷ 1350 sq ft a roll. Lapped like shingles, top over bottom (water-resistive barrier, IRC R703.2). | The water-resistive barrier over the sheathing, lapped like shingles, top over bottom. |
| **1 roll** | House wrap tape (1⅞″ × 165 ft) | Seams and cuts in the wrap. | Seals the seams and the cuts in the wrap. |
| **1 box** | Plastic cap nails (for the wrap (or cap staples)) | About one box per 1500 sq ft of wrap. | Nails with a wide plastic washer that hold underlayment without tearing it. |
| **1 roll** | Window and door flashing tape, 4″ × 75 ft | 65 ft around the rough openings (sill, jambs, head) + 15% for laps (flashing at openings, IRC R703.4). | Flashes the rough openings: sill first, then the jambs, then the head over the fin. |
| **3 windows** | Window, new construction (nailing fin) (36″ × 60″ rough opening, U-0.30 or lower, SHGC 0.40 or lower) | Your count and average size. Energy rule for zone 4: U-0.30 or lower, SHGC 0.40 or lower. Sleeping rooms need one egress window (IRC R310; R319 in the 2024 IRC). | U-factor and SHGC from the energy code for your zone; sleeping rooms need an egress size. |
| **1 door** | Exterior door, 36″ pre-hung (36″, rough opening 38″ × 82-1/2″) | Your count, pre-hung with the sill. | Insulated steel or fiberglass, pre-hung with the sill; rough opening about 38″ × 82½″. |
| **1 pan** | Door sill pan (to the door width) | One under each exterior door. | Under each exterior door: catches water at the threshold. |
| **2 tubes** | Exterior sealant (paintable) (10 oz tubes) | The two vertical joints where the new walls meet the house (8′ 11-1/8″ each), about 25 ft a tube, + one for the penetrations. | Siliconized acrylic or elastomeric sealant rated for outdoors; stays flexible as siding moves. |
| **2 boxes** | Vinyl siding (box of 2 squares) (2 squares a box) | 322 sq ft of wall (openings out) + 10% = 355 sq ft ÷ 200 sq ft a box. | A square covers 100 sq ft. Hang it loose so it can move. |
| **129 ft** | Siding trim (starter, J-channel, corners) (starter, J-channel, corner posts) | Corners (18 ft), around the openings (65 ft) and under the eaves and rakes. | Starter at the bottom, J-channel around openings and under the eaves, posts at the corners. |
| **1 box** | Siding nails, galvanized (box) (galvanized, through any foam into the framing) | About one 5 lb box per 8 squares. | Long enough for the sheathing plus any foam. |
| **47 ft** | Soffit and fascia (vented soffit at the eaves, fascia all around) | 26 ft of eaves + 20 ft of rakes. | Vented soffit under the eaves, fascia cover on the roof edge. |
| **allowance for 192 sq ft** | Electrical — allowance (by the licensed electrician) | Circuits, outlets, lights, smoke and CO alarms for 192 sq ft of new floor. A placeholder until the electrician’s quote — a panel upgrade, if needed, is extra. | Circuits, outlets, lights and smoke/CO alarms by a licensed electrician, on their own permit. Replace it with their quote. |
| **allowance for 192 sq ft** | Heating and cooling — allowance (by the HVAC contractor) | Heating and cooling for 192 sq ft: extended ducts or a ductless unit, sized by a load calculation. | Extended ducts or a ductless unit, sized by the HVAC contractor (a load calculation), on their own permit. Replace it with their quote. |
| **219 sq ft (buy by the coverage on the bag)** | Wall batts for 2×6 (R-19 to R-24) (R-21, kraft-faced, 15″ wide) | 40′ of outside wall × 8′ 1-1/8″ − openings, less 15% for the framing. Planned with R-21 batts + R-5 continuous foam for zone 4 (R-30, R-20 + R-5 continuous, R-13 + R-10 continuous, or R-20 continuous, IECC 2021 Table R402.1.3). | Kraft-faced where the code wants a vapor retarder on the warm side; buy by the coverage on the bag. |
| **10 sheets** | Exterior rigid foam 1″ (R-5), 4×8 (1″ (R-5), seams taped) | Over the wall sheathing, under the wrap: 290 sq ft of wall (openings out, the attic gable left bare) + 10% ÷ 32 sq ft. Window and door jambs get extension jambs. | Continuous insulation over the sheathing (foil-faced polyiso or XPS), seams taped; the wrap and siding go over it. |
| **202 sq ft at R-60** | Blown-in attic insulation (R-60 (about 22″ of loose fill — read the bag chart)) | 192 sq ft of top-floor ceiling + 5% at the heels. R-60 (IECC 2021 Table R402.1.3). | Loose-fill fiberglass or cellulose to the R-value on the bag’s chart; most stores lend the blower. |
| **173 sq ft (by the bag’s coverage)** | Floor batts (R-13 to R-38) (R-19, with supports) | 192 sq ft of floor over the vented crawlspace, less 10% for the joists. R-19 (IECC 2021 Table R402.1.3). | Between the floor joists over a vented crawlspace, held up against the subfloor with supports. |
| **2 cans** | Spray foam, gaps and cracks (12 oz cans) | Air-sealing the plates, the rim, the window shims and the wire and pipe holes: about one can per 25 ft of wall per story. | Seals corners, pipe holes and gaps at the top of the foam. Use one labeled safe for foam board. |
| **2 cans** | Fireblock sealant (fire-rated foam) (12 oz cans) | Fire-rated foam at the top plates and floor penetrations (fireblocking, IRC R302.11). | Seals the top of the wall cavity where it meets the joists, and around soffits. Ordinary canned foam is not a fireblock. |
| **9 sheets** | Drywall ½″ (½″, 4×12 sheets) | (40′ of outside wall + 16′ along the house) × 8′, − openings = 361 sq ft + 12% for cuts ÷ 48 sq ft. | Standard gypsum board for walls. |
| **5 sheets** | Drywall ½″ ceiling board (sag-resistant) (½″ ceiling board, 4×12 sheets) | 192 sq ft + 12% ÷ 48 sq ft. Sag-resistant board for framing 24″ apart with insulation on top. | Rated for ceilings with framing 24″ apart and insulation on top. |
| **≈589 screws (3 lb)** | Drywall screws, coarse thread (1¼″ coarse thread) | USG spacing: 4 per stud on walls (16″ apart), 5 per joist or truss on ceilings (12″ apart), + 10%. About 250 per lb. | Coarse thread bites wood studs. |
| **2 pails** | All-purpose joint compound (4.5-gal pail (≈62 lb)) | 5.5 gal: about 10 gal per 1,000 sq ft of board (USG), three coats. | Premixed “mud” for taping and finish coats. |
| **1 roll** | Paper joint tape (250 ft roll) | 204 ft: about 370 ft per 1,000 sq ft of board (USG). | Bedded in mud over seams and inside corners. |

### In Canada (4.88 m × 3.66 m addition)

Set to Canada, the Sheet works the job out again for Ontario: metric sizes, bag sizes, the frost depth and the code notes. It doesn't just convert feet to meters. The first lines:

- **1 survey, Survey or plot plan:** Zoning (setbacks, lot coverage, height) and the permit office work from it, and it places the footings.
- **1 set, Plans and engineering:** Architect or designer drawings, the engineer’s foundation and beam details, and the energy compliance for NBC zone 6.
- **1 permit, Building permit and plan review:** An addition needs a building permit from your municipality’s building department, usually with drawings by an architect, an engineer or a qualified designer, and zoning first (setbacks, lot coverage, height). Plan review takes weeks. The electrical, plumbing, gas and HVAC work goes to licensed trades with their own permits. Confirm with your building department.
- **1 haul, Dumpster (20-yard roll-off):** Framing offcuts, packaging, roofing and drywall scraps, and the old siding along the house: about one 20-yard haul per 37.2 m² of new floor. Spoil from the dig goes by truck, not in the dumpster. The dig: about 22.91 m³ out, 11.39 m³ back in as backfill, ≈14.40 m³ loose to truck away (25% swell).
- **1.25 m³ (one pour), Ready-mix concrete (delivered):** 12.19 m of footing × 406 mm wide × 203 mm thick = 1.01 m³, + 10% for the trench’s uneven bottom = 1.11 m³, ordered up to the next quarter. NBC Table 9.15.3.4: at least 250 mm wide under one floor, 350 mm under two, and as thick as the projection (100 mm minimum) — size it for your soil.
- **5 bars, Rebar #4 (13 mm):** Two continuous #4 bars in the footing (24.38 m + 10% for laps and corners). Required in seismic areas and common everywhere — follow the plans.

## The steps, in order

> **PRO STEP: most of it is DIY-friendly; one step needs a licensed pro.** About 162–248 hours of work for this example.

1. Zoning check: setbacks, lot coverage and height with the zoning office, and a survey or plot plan with the new footprint.
2. Plans: drawings by the architect or designer, the engineer’s foundation and beam details, and the energy forms for zone 4.
3. Pull the building permit (plan review), then line up the licensed trades and order the trusses (lead time) and windows.
4. Call 811 for a locate ticket and wait for the marks; stake the footprint and set batter boards, carrying the house’s floor height out to the new floor.
5. Excavate the footing trench and the crawlspace: about 25.3 cu yd out, footings on undisturbed soil below the frost line.
6. Footing inspection, then pour the footings with the bars on chairs.
7. Form and pour the foundation walls (3′) with the anchor bolts in place; strip the forms.
8. Foundation inspection; dampproof below grade.
9. Crawlspace: vapor retarder on the ground, lapped and run up the walls, vents near each corner, and the access door.
10. Sill on the gasket, bolted down; floor joists at 16″ (hangers at the ledger on the house); glue and fasten the subfloor.
11. Backfill and grade away from the house once the floor is framed (or the walls are braced).
12. Frame the walls: plates, studs at 16″, corners and headers per the plans; stand, plumb, brace and sheathe them.
13. Set the trusses with the truss drawings and bracing plan on site, hurricane ties at every bearing, then the roof sheathing.
14. Dry it in: drip edge, underlayment, shingles, and step flashing with kick-outs where the roof meets the house; house wrap lapped like shingles over the continuous foam.
15. Windows and doors: flash each rough opening (sill, then jambs, then head), set them level and plumb, tape the fins.
16. Siding, trim, soffit and fascia.
17. Open the house wall last: shore it, cut the opening, set the header the engineer sized, and seal the joints where the walls meet.
18. Rough-ins by the licensed trades (electrical, plumbing, HVAC), then the framing and rough-in inspections.
19. Insulation per the zone — walls, ceiling, floor or crawlspace walls — and air-seal the plates and holes; insulation inspection.
20. Hang the drywall (ceilings first), tape, three coats of mud, sand and prime.
21. Final inspection and the certificate of occupancy (or approval); hand the permit papers to the owner.

## Tools (47)

Must-have tools first, then the ones that help and the ones to rent for the day.

| Tool | Need | Why |
|---|---|---|
| **Tape measure (25 ft)** | **Must have** | The red boxes every 16″ on the blade are stud spacing. |
| **Mason's line + stakes** | **Must have** | Batter boards and string lines set the footprint |
| **Rotary laser + grade rod** | Rent | Footing, wall and slab heights — and the house’s floor height carried out |
| **Mini excavator** | Rent | Digs the footing trench |
| **Square shovel** | **Must have** | Cuts clean trench walls, moves gravel. |
| **Wheelbarrow** | **Must have** | Moves gravel, soil and block. |
| **Plate compactor** | Rent | Compacts the stone base and the backfill in lifts |
| **Rebar cutter-bender** | **Must have** | Cuts and bends the bars for laps and corners |
| **Rebar tie tool** | Good to have | Twists the ties fast |
| **Concrete vibrator** | Rent | Consolidates the wall pour so there are no voids |
| **Chalk line** | **Must have** | Snaps a long straight line on floors, subfloors and ceilings. |
| **Framing square** | **Must have** | Big steel L-square. With stair gauges it lays out stair stringers. |
| **Speed square** | **Must have** | Triangle square for marking square and angled cuts on lumber. |
| **4-ft level** | **Must have** | Checks plumb and level over a long span. |
| **Cross-line laser level** | Good to have | Plumbs and lines the walls |
| **Circular saw** | **Must have** | Handheld power saw for lumber and sheet goods. |
| **Miter saw** | Good to have | Square cripples, blocks and trim |
| **Reciprocating saw** | **Must have** | Cuts the opening into the house |
| **Framing nailer + compressor** | Rent | Framing, sheathing and the subfloor |
| **Framing hammer** | **Must have** | Nails, taps and persuades. |
| **Impact driver** | **Must have** | Ledger screws and the subfloor |
| **Cordless drill/driver** | **Must have** | Drills holes, drives screws, mixes small batches. |
| **Hammer drill + masonry bit** | Rent | Anchors into the existing foundation |
| **Caulk gun** | **Must have** | Dispenses caulk and adhesive. |
| **Cap stapler** | **Must have** | Fastens the house wrap and underlayment |
| **Utility knife + blades** | **Must have** | Scores drywall and vinyl plank, trims pad. Swap blades often. |
| **Aviation snips** | **Must have** | Flashing and drip edge |
| **Coil roofing nailer** | Rent | Shingles |
| **Air compressor + hose** | **Must have** | Runs the framing and roofing nailers |
| **Fall-protection kit** | **Must have** | Roof work and open edges 6 ft up and more |
| **Hard hat** | **Must have** | Overhead work and the machine on site |
| **Extension ladder (24 ft)** | **Must have** | Reaches roofs, gutters and second floors; pick fiberglass near wires. |
| **Frame scaffolding** | Rent | Sheathing, wrap and siding up high |
| **Adjustable steel shoring posts** | Rent | Hold up the house while its wall is opened |
| **Siding zip tool** | **Must have** | Unlocks vinyl courses |
| **Snap-lock punch** | **Must have** | Locks the top course under the trim |
| **Insulation blowing machine** | Rent | Blows the attic insulation |
| **Drywall lift** | Rent | Ceiling sheets |
| **Drywall T-square** | **Must have** | Guides straight, full-width drywall cuts. |
| **Drywall dimpler bit (or screw gun)** | **Must have** | Sets drywall screws just below the paper — no torn paper, no popped heads. |
| **Mud pan** | **Must have** | Holds joint compound while you work. |
| **6″ taping knife** | **Must have** | First coat: bed the tape, fill screw heads. |
| **10–12″ taping knife** | **Must have** | Wide knife for thin, feathered final coats. |
| **Safety glasses** | **Must have** | Every cut, every nail, every time. |
| **Hearing protection** | **Must have** | Saws and nailers are loud enough to damage hearing. |
| **Work gloves** | **Must have** | Lumber, sheathing, rebar and block |
| **N95 dust masks** | **Must have** | Drywall sanding and general dust. |

## Mistakes and how the math works

### Mistakes that cost a callback or a second trip

- **Skipping the zoning check:** Setbacks, lot coverage and height decide whether the addition can be built at all. A survey costs less than moving a footing.
- **Missing the floor height:** Carry the house’s floor height out before the foundation goes in: the new floor should meet it (or the step is planned), not surprise you at the doorway.
- **Backfilling unbraced walls:** Backfill before the floor is framed or the walls are braced and they can crack or move. Wait for the inspection and the dampproofing too.
- **Leaky roof-to-wall flashing:** Most addition leaks start where the new roof meets the house: step flashing with every course, kick-outs at the bottom, and the house’s wrap and siding lapped over them.
- **Opening the house too early:** Keep the house closed until the addition is dried in. Then shore, cut and set the engineer’s header the same day.

### What the calculator assumes

- Takeoff for a pro: it counts pieces and never sizes structure. Footings, headers, beams, girders, the opening into the house, the ledger fastening and uplift come from the engineer or the code tables; trusses from the truss maker.
- Footings: IRC R403.1.1 — at least 12″ wide and 6″ thick, projecting 2″ to their thickness past the wall; R403.1.4 — at least 12″ below undisturbed ground and below the frost line. Confirm with your building department.
- Anchor bolts: ½″ bolts, 7″ into the concrete, no more than 6 ft apart, at least two per plate piece with one within 12″ of each end (IRC R403.1.6). Confirm with your building department.
- Foundation walls 8″ concrete or block, the top 6″ or more above grade (R404.1.6); slab 4″ on a 4″ stone base with 6-mil poly lapped 6″ (R506); dampproofing below grade (R406); a footing drain around a basement (R405). Confirm with your building department.
- Crawlspace (IRC R408): vents within 3 ft of each outside corner, 1/150 of the floor area or 1/1,500 with a Class I vapor retarder on the ground; or a sealed crawlspace with the retarder lapped 6″, run 6″ up the walls, and conditioned air or exhaust; access at least 16″ × 24″ through the wall. Confirm with your building department.
- Studs (IRC Table R602.3(5)): 2×4 at 24″ under a roof only and 16″ under a floor and roof; 2×6 at 24″ under one floor, 16″ under two; double top plates lapped 24″; walls up to 10 ft without engineering. Confirm with your building department.
- Precut studs: 92⅝″ for 8 ft walls, 104⅝″ for 9 ft, 116⅝″ for 10 ft, with a bottom plate and a double top plate. Studs: layout at the spacing + 2 per outside corner + 4 per opening (6 for a patio door) + 10%.
- Trusses at 24″ on center, designed by the truss maker (IRC R802.10, ANSI/TPI 1), with gable-end trusses at the ends.
- Roof: area = plan area with the overhangs × the slope factor (the same pitch on every plane); waste 10% (gable, shed) or 15% (hip); 3 bundles a square; 4 nails a shingle; drip edge at eaves and rakes (R905.2.8.5); ice barrier to 24″ inside the wall line where required (R905.1.2); two layers of underlayment under 4:12.
- Sheathing and siding: wall area with the gable or rake triangles, less the openings, + 10%; house wrap + 15% for laps.
- Insulation for zone 4 (IECC 2021 Table R402.1.3): walls R-30, R-20 + R-5 continuous, R-13 + R-10 continuous, or R-20 continuous; ceiling R-60; floors over a crawlspace R-19; crawlspace and basement walls R-10 continuous or R-13 cavity; slab edge R-10, 4 ft deep; windows U-0.30 or lower, SHGC 0.40 or lower. Confirm with your building department.
- New Jersey adopted the 2024 IRC and IECC effective Aug 17, 2026, with a grace period — your permit may use either edition. Ask your town which one.
- Drywall: ½″ walls and ½″ ceiling board, 4×12 sheets, + 12%; screws, mud and tape at USG rates. Labor at typical production rates for a framing crew; your own numbers replace them.
- Allowances for the licensed trades and the soft costs (plans, survey, dumpster) are typical US figures to hold a place in the estimate — replace them with quotes. Permit fees are set locally and left unpriced.

## Code, permits and safety

The Sheet sets its code notes for the job's state or province. These are New Jersey's and Ontario's; the [code reference](https://studsheet.com/codes) has more. Always confirm with your building department.

- **Permit, zoning and stamped drawings:** An addition needs a construction permit from your town’s construction office, usually with drawings sealed by a licensed architect or engineer, and zoning first (setbacks, lot coverage, height). Plan review takes weeks. The electrical, plumbing and HVAC work goes on the licensed trades’ own permits.
- **Structural sizing: the engineer’s call:** This Sheet counts pieces; it doesn’t size structure. The engineer (or the code’s prescriptive tables, where your building department accepts them) sizes the footings for your soil, the headers and beams, the opening into the house, girders and posts, the ledger fastening and the uplift connections (IRC R403.1 footings, R502 floors, R602.7 headers, R802 roofs). Trusses are designed by the truss maker. Anything outside the tables — long spans, point loads, building over the old house — is the engineer’s.
- **Licensed trades on their own permits:** In New Jersey the wiring goes to a licensed electrical contractor, plumbing and gas to a licensed master plumber, heating and cooling to a licensed master HVACR contractor — each pulls their own subcode permit. The allowances on this Sheet hold their place in your estimate until their quotes come in; their rough-ins are inspected with the framing.
- **Inspections, in order:** Footing (before the pour) → foundation (forms or block, then the dampproofing and drain before backfill) → slab or under-floor → framing, with the electrical, plumbing and mechanical rough-ins → insulation → final and the certificate of occupancy or approval. Many places add a sheathing-nailing or fireblocking check. Book each one ahead, and keep the card signed on site.
- **Frost depth:** Footings go below the frost line and at least 12″ below undisturbed ground (IRC R403.1.4). Frost line: 36″ in Mercer/Middlesex and north, 30″ south. Confirm with your building department. This footing’s bottom is about 3′ below grade.
- **Call 811 first — it’s the law:** In New Jersey, call 811 (NJ One Call) at least 3 full business days before digging. Free. Wait for the utility markings.
- **Insulation for zone 4:** Walls: R-30, R-20 + R-5 continuous, R-13 + R-10 continuous, or R-20 continuous. Ceiling: R-60. Floor over the vented crawlspace: R-19. Windows: U-0.30 or lower, SHGC 0.40 or lower (IECC 2021 Table R402.1.3). Planned for zone 4. Bergen, Hunterdon, Morris, Passaic, Somerset, Sussex and Warren counties are zone 5 (NJ DCA Bulletin 22-1): pick it under Climate zone if you build there (floors over a crawlspace go from R-19 to R-30). Confirm with your building department.
- **Click Before You Dig:** Before you dig, request a free utility locate from Ontario Dig Authority (ontariodigauthority.ca) at least 5 business days ahead, and wait for the markings.
- **Insulation for NBC zone 6:** Walls: effective RSI 3.08 (R-17.5), or RSI 2.97 with a heat-recovery ventilator. Ceiling: effective RSI 8.67 (R-49.2). Floor over the vented crawlspace: effective RSI 4.67 (R-26.5). Windows: U-1.60 W/(m²·K) or lower (Ontario’s SB-12 (NBC 9.36 values shown)). Planned for NBC climate zone 6, typical for most of Ontario. Your municipality’s heating degree-days set the zone (NBC Appendix C): pick it under Climate zone. Confirm with your building department or energy evaluator.

## Questions

### What materials do I need to frame a room addition?

For the worked example, a 16′ × 12′ addition, the Sheet counts 72 lines with waste included, starting with survey or plot plan (1 survey), plans and engineering (1 set), building permit and plan review (1 permit), dumpster (20-yard roll-off) (1 haul). Each line's math is in the table above. Put in your own sizes in the [addition calculator](https://app.studsheet.com/p/addition) and every line is counted again.

### How long does it take to frame a room addition, and can I do it myself?

About 162 to 248 hours for the worked example, in 21 steps. StudSheet stamps it **PRO STEP**: dIY with a pro for one step.

### What tools do I need to frame a room addition?

47 in all. The must-haves start with tape measure (25 ft), mason's line + stakes, square shovel, wheelbarrow, rebar cutter-bender, chalk line. On the Sheet you mark each one as owned, to buy or to rent.

## Ask about it

Stuck while you frame a room addition? Ask in the [Additions group](https://studsheet.com/forum/additions) of the StudSheet community with this Sheet attached. Homeowners who've done it and verified pros answer, and anyone can read it.

## More general contracting Sheets

- **[Remodeling and additions for contractors](https://studsheet.com/trades/remodeling)**: run this takeoff at your own prices, send the estimate, and get it signed and the deposit paid.
- **[Finish a basement](https://studsheet.com/sheets/basement)** (28′ × 25′ basement): Foam, framing, drywall, a drop ceiling and the floor — in the order the inspector wants it.
- **[Mount a TV](https://studsheet.com/sheets/tv)** (65-inch TV, tilting mount): The right mount for your TV and wall, where to put it, what holds it (studs, toggles or masonry anchors) and how to hide the cables.
- **[Re-caulk a tub, shower or sink](https://studsheet.com/sheets/caulk)** (Tub, 22 ft of caulk): Old caulk out, mildew killed, backer rod where the gap is wide, and the right silicone — with tubes counted from the joints you have.
- **[All 45 Sheets](https://studsheet.com/sheets)**, across 16 trades.
- **[Code reference](https://studsheet.com/codes):** frost depths, guard heights, stairs, retaining walls.