Your house, costed.

Everything starts from one division: finished square footage ÷ stories = footprint. The footprint is treated as a 1.5:1 rectangle for wall lengths, openings and rooms are counted by density rules, and the roof is drawn over the footprint, the garage, and the porch. Those few derived numbers feed every phase, each of which prices a short list of real line items at national rates as of October 2026, scaled by the state you pick. Open any row on the ledger to see its lines; the defaults below are for the 2,000 sq ft house.

Before you break ground. The building permit is a state base plus $0.35 per heated square foot, with plan review, the survey, the water and sewer tap or impact fees (the state table carries the band), twelve months of builder's risk insurance at half a percent of the hard cost, and the plans. Paid, not built, so there is no labor switch.

Site work. Fill and topsoil, a 100-ft gravel drive at 8 in deep, silt fence around the disturbed area, a stone construction entrance, and a temporary power pole. Clearing and grading are equipment and labor, which is why this phase carries the highest labor ratio on the ledger.

Foundation. A slab is 4 in over the house and garage with a 20 × 12 in turned-down footing, mesh, rebar in the footing, a vapor barrier, and 4 in of gravel (49 yd³ in the default house, with a 10% order factor). A crawl space swaps that for a continuous footing, a 3-ft block stem wall, piers every 200 sq ft, a treated sill, and vents, and the first floor becomes framed. A basement is 8-ft poured walls on footings with a slab, waterproofing, and drain tile. The concrete slab calculator prices a pour from your actual dimensions.

Framing. The same conventions as the framing lumber calculator: one stud per linear foot of wall at 16 in on center, three runs of plate in 16-ft sticks, a doubled header per opening, 4 × 8 OSB with 10% waste, house wrap, then joists and subfloor for any framed floor, trusses at 2 ft on center over the plan area, roof sheathing, porch posts, and allowances for blocking and fasteners. The default house takes 243 exterior studs, 500 partition studs, and 40 trusses.

Roofing. Sloped area is the plan area times the pitch factor (6:12 by default), with 10, 15, or 20% waste by how cut up the roof is; three bundles per square (107 in the default house), synthetic underlayment, ice and water on the eaves, starter, cap, drip edge, ridge vent, flashing, and nails, as the roofing calculator counts them.

Windows and exterior doors. One window per 110 sq ft at 15 sq ft each, an entry door with sidelights, a patio door, a back door, and a 16-ft garage door with its opener when the house is large enough to carry a garage. Finish level moves these: basic is 0.85× the standard rate, premium 1.3×.

Exterior finish. Fiber-cement lap siding on the wall area after openings with 10% waste, trim at corners, openings, and the band, soffit and fascia on the eaves and rakes, aluminum gutters with four downspouts, and a caulk-and-flashing allowance. Finish-sensitive.

Plumbing, electrical, HVAC. Plumbing is priced per fixture for the rough-in (three per bath, two in the kitchen, two in the laundry, two hose bibs) plus the service lines, water heater, and finish fixtures. Electrical is a 200-amp service, wire and boxes per heated square foot, devices and a fixture allowance per room, and detectors. HVAC is a heat pump at one ton per 600 sq ft, moved by the state's climate, with ductwork per square foot, a thermostat, and bath fans. These three carry a licensed-trade note because many states require one.

Insulation, drywall, paint. R-19 batts in the walls and blown fiberglass to R-49 in the attic by the insulation calculator's bag charts, with floor batts under a crawl space or rigid foam on basement walls. Board is the drywall calculator's 3.7 × floor area (270 sheets in the default house) with compound, tape, screws, and corner bead; paint is the paint calculator's primer plus two coats at 350 sq ft per gallon, with trim enamel per room.

Interior finish and final. Interior doors are rooms minus two; baseboard runs the finished wall perimeter; flooring is the heated area with 8% waste at a blended plank, tile, and carpet rate (the flooring calculator does it by room); cabinets, vanities, countertops, bath tile, shower glass, and accessories are counted by kitchen and bath. The final phase is the appliance package, 870 sq ft of concrete drive and walks, seed and shrubs, the last clean, three dumpsters, and the odds and ends.

Labor and the state index. Each phase's labor is its material cost times a ratio calibrated to 2026 subcontractor quotes (framing 1.1, drywall and paint 1.9, electrical 1.5, openings 0.3), then the state's labor index. Hours are that figure at a blended crew rate of $45 an hour ($65 for the licensed trades). The materials index is narrow, since lumber and concrete travel; the labor index is wide, since crews do not. North Carolina is 1.00. The permit base and tap fees are set per state and are not scaled again.

The land, the loan, and the furniture. The ledger also assumes a buildable lot with utilities at the street and a typical footprint; a well and septic, a long power run, rock, extra fill, a retaining wall, or an unusual shape are on top. Track what you actually spend against the phases in the budget tracker, and carry the contingency.

Order 10–15% extra on anything you cut. Waste, mistakes, and future repairs all come out of the same pile. It matters most for materials that get discontinued — flooring, tile, siding — where a matching board three years from now is worth more than the storage space it took.

Open contractor accounts. Set up accounts at real lumberyards and suppliers rather than buying retail. Better pricing (usually 10–20% off), delivery scheduling, and access to contractor-grade material that the big boxes do not stock. This is the largest discount available to an owner-builder for the least effort.

Time orders to the schedule, not the budget. Bring material in 1–2 weeks before you need it. Buying everything up front invites theft, weather damage, and ties up cash you will want later. The exception is lumber: if the market is low and you have dry covered storage, locking a price in is defensible. Sequence your orders against your build timeline and the framing phase in particular, since that is where the biggest single delivery lands.

Inspect every delivery before you sign. Count it, look for damage, check that it is what you ordered. Getting credit after the driver pulls away is a different and much worse conversation.

Store it like it cost you money. Wet lumber warps, wet drywall is scrap, and moisture-damaged material causes problems that surface a year later. Tarps on, material up off the dirt, stacked flat.

Keep every receipt. Track each purchase against the phase it belongs to. You will need it for budget tracking, for warranty claims, and occasionally for an inspector who wants to see a product spec.