A home addition estimate template written from the contractor's side of the job.
This is a free home addition estimate template with the whole build already itemized, permits through closeout: design and engineering, demolition and site prep at the tie-in, foundation, framing, roofing and exterior, windows and doors, mechanical rough-ins, insulation and drywall, interior finishes, and the labor and contingency lines at the end. Load it in the builder, delete what your addition doesn't need, and put your rates on what's left. The rates come blank because they depend on your market.
Search for a room addition estimate template and most results tell homeowners what other additions cost per square foot, which is not an estimate. An addition is a small house attached to an occupied one, which is why this template carries a Temporary protection & dust barriers line, a Selective demolition at tie-in line, and three separate inspection lines: foundation, rough-in, final.
What’s in the template
This is the exact checklist that loads in the builder, with each line’s unit already set. Delete what this job doesn’t need.
Permits & preconstruction4 lines
Design and engineering, the building permit, mobilization, and the dust barriers that keep the rest of the house livable. Flat lines, quoted before work starts.
- Design & engineeringflat
- Building permit & feesflat
- Mobilizationflat
- Temporary protection & dust barriersflat
Lump-sum items (permits, design, engineering) quoted flat.
Demolition & site prep6 lines
Selective demolition at the tie-in, clearing and grubbing, excavation and backfill by the cubic yard, gravel by the ton, and hauling off what came out.
- Selective demolition at tie-inflat
- Site clearing & grubbingflat
- Excavationcu yd
- Gravel baseton
- Backfill & compactioncu yd
- Demolition debris disposalflat
Excavation and fill quoted by cu yd; bulk gravel by weight.
Foundation5 lines
Footings and foundation walls by the linear foot, slab by the square foot, waterproofing, and the first of the three inspections.
- Footing - form & pourln ft
- Foundation wallln ft
- Slab - pour & finishsq ft
- Foundation waterproofingsq ft
- Foundation inspectionflat
Footings and foundation walls quoted by ln ft; slab by sq ft.
Framing7 lines
Floor, wall, and roof framing by the square foot, sheathing by the sheet, beams and headers per unit, house wrap, and framing labor by the day.
- Floor framing & subfloorsq ft
- Wall framingsq ft
- Roof framingsq ft
- Sheathingsheet
- Beams & headerseach
- House wrapsq ft
- Framing laborday
Framed assemblies quoted by sq ft of area; sheathing by sheet.
Roofing & exterior7 lines
Underlayment and shingles by the square, flashing and drip edge, fascia, gutters, siding, and the exterior trim that ties the addition into the house it's attached to.
- Roofing underlaymentsquare
- Shingles - installsquare
- Flashing & drip edgeln ft
- Fascia & soffitln ft
- Gutters & downspoutsln ft
- Siding - installsq ft
- Exterior trimln ft
Roofing coverage by square (100 sq ft); trim and gutter runs by ln ft; siding by sq ft.
Windows & doors5 lines
Windows and doors per opening, plus the flashing, weatherstripping, and caulk that decide whether they leak.
- Windows - installeach
- Exterior door - installeach
- Interior door - installeach
- Window & door flashingeach
- Weatherstripping & caulkflat
Mechanicals - rough-in7 lines
Electrical, plumbing, and HVAC rough-ins quoted flat, water and waste lines by the linear foot, equipment set per unit, and the rough-in inspection.
- Rough-in electricalflat
- Electrical panel & circuitsflat
- Rough-in plumbingflat
- Water & waste linesln ft
- HVAC - ductworkflat
- HVAC equipment - seteach
- Rough-in inspectionflat
System rough-ins quoted flat; water and waste lines by ln ft.
Insulation & drywall6 lines
Wall and ceiling insulation, vapor barrier, drywall hung by the sheet and finished by the square foot, and primer by the gallon.
- Wall insulationsq ft
- Ceiling insulationsq ft
- Vapor barriersq ft
- Drywall - hangsheet
- Drywall - tape & finishsq ft
- Prime walls & ceilinggal
Insulation, vapor barrier and drywall finish by sq ft; drywall boards by sheet; primer by gal.
Interior finishes8 lines
Flooring, baseboard and casing, paint, trim-out for electrical and plumbing, registers, cabinets, and countertop.
- Flooring - installsq ft
- Baseboard & casingln ft
- Interior paintgal
- Electrical - trim outeach
- Plumbing fixtures - seteach
- HVAC registers & grilleseach
- Cabinets - installeach
- Countertop - installln ft
Flooring and paint area by sq ft; trim and countertop runs by ln ft; paint by gal.
Labor, cleanup & closeout6 lines
General labor by the day, the dumpster, final cleanup, final inspection, and the general conditions and contingency lines.
- General laborday
- Dumpster & disposalflat
- Final cleanupflat
- Final inspectionflat
- General conditionsflat
- Contingency allowanceflat
Lump-sum items quoted flat; general labor by day. Overhead & profit is the percentage modifier.
Questions
Units, tax, deposits and exports are covered in the Help guide.
For the longer answer, there’s a guide: How to Write a Construction Estimate.
What does a home addition estimate include?
Ten sections that follow the build in order: permits and preconstruction, demolition and site prep, foundation, framing, roofing and exterior, windows and doors, mechanical rough-ins, insulation and drywall, interior finishes, and labor, cleanup and closeout. Inside them are the lines that drop off addition quotes: backfill and compaction, house wrap, window and door flashing, the dumpster, and the rough-in inspection that has to pass before the drywall goes up. Delete what your addition doesn't need and rename what's left.
How do I price a home addition?
By its drivers, one line at a time. Excavation and backfill run by the cubic yard, gravel by the ton, footings and foundation walls by the linear foot, framed floor, wall, and roof areas by the square foot, roofing by the square, windows and doors per opening, rough-ins as flat scopes, and labor by the day. The math never changes underneath: rate, quantity, multiplier, whatever the unit label says. The live P&L totals your side as you go, so you know the margin on the whole build before you commit to it.
How do I handle the tie-in and other unknowns on an addition estimate?
As priced lines. The template ships with a Selective demolition at tie-in line for the wall where new meets old, and a Contingency allowance under closeout for what that wall turns out to contain. General conditions gets its own flat line instead of hiding inside your rates. For the money mechanics, document modifiers cover an overhead and profit fee as a percentage of the subtotal, a discount, and an informational deposit line that shows the client what's due up front without changing the total.
Is the home addition estimate template free?
Yes. The whole builder runs without an account, and every estimate export works on free: client PDF, Excel, CSV, plus the internal budget export, and share links pack a client-safe copy into the link. A free account adds one cloud-saved estimate. Pro is a one-time purchase, not a subscription: your branding on client exports, no Estimatery footer, invoice exports, unlimited cloud saves, and a Saved Items catalog of your standard lines.
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General information for pricing your own work. Not legal, tax or accounting advice. Deposit caps, licensing, lien and permit rules vary by state.