Custom Home Specification Schedule: The Page That Decides What “Included” Means
Custom Home Specification Schedule: The Page That Decides What "Included" Means
Two builders can quote the same drawings 150,000 dollars apart and both be honest. The difference is in the specifications: what the walls are made of, what the windows are, what “allowance” means. This is the document that makes quotes comparable and arguments short.
Why it matters more than the drawings
The drawings show where the wall is. The specification says whether it is 2×6 with batts, ICF, or 2×6 with exterior foam, what the siding is, what the windows are and who makes them. Two builders can read the same drawing and price completely different houses. When you compare quotes, you are comparing specifications, whether you know it or not. Questions before signing and what a good contract includes are the companions to this page.
It also governs the arguments later. “I thought that was included” is settled in thirty seconds by a specification schedule and in three months by a lawyer without one.
The template: sections and the lines each needs
Copy the headings; the lines under each are what a complete schedule answers. Where you have not chosen, write an allowance amount and what it covers.
| Section | Lines to fill |
|---|---|
| Site and excavation | Clearing included (area); excavation and backfill; granular under slab; rough and final grading; driveway base and surface; septic (design, size, type) or sewer connection; well or water connection; hydro service size and trenching; culvert and entrance |
| Foundation | Type (ICF, poured, block); wall thickness and height; footing size per engineer; rebar; waterproofing or damp-proofing product; drainage membrane; weeping tile and outlet; sump; under-slab insulation; slab thickness; radon rough-in |
| Structure | Wall system and thickness; floor system (joists or trusses, depth); subfloor; roof trusses and loading; sheathing; beams and posts per engineer; steel if any; garage slab |
| Envelope | Insulation values: attic, walls, basement, slab; air barrier and vapour barrier products; house wrap or foam; window brand, line, glazing (double or triple, low-e, argon), frame material, colour; exterior doors (material, lites, hardware); garage doors (insulated, openers) |
| Roof | Shingle brand and warranty or metal profile; underlayment; ice and water shield extent; ventilation; eavestrough and downspouts (material, size); fascia and soffit |
| Exterior finishes | Siding type, brand, profile, colour, extent per elevation; stone or brick (extent, allowance per square foot); trim material; decks and porches (framing, decking, railings); exterior lighting allowance |
| Mechanical | Heating system type and make; boiler or furnace size per heat loss; radiant zones; air conditioning; HRV or ERV make; ductwork; thermostats; water heater type and size; gas lines; fireplace (type, venting) |
| Plumbing | Fixture count by room; fixture allowance or named fixtures; water treatment; hose bibs; floor drains; rough-in for future bath |
| Electrical | Service size; panel; number of circuits or outlets per room; pot light count; fixture allowance; exterior outlets; EV charger rough-in; data and low-voltage; generator rough-in |
| Interior finishes | Drywall level; ceiling heights by floor; interior doors (style, material); trim profile; paint (coats, brand, sheens); flooring by room with allowance per square foot; tile by room with allowance; stairs (material, railings) |
| Kitchen and bath | Cabinet allowance or named supplier and line; countertop material with allowance; backsplash; appliances (included or not); vanities; shower (tiled or acrylic, glass); accessories |
| Allowances and exclusions | Every allowance in one list with the amount and what it covers; markup on overages; what is excluded (landscaping, fencing, appliances, window coverings, HST); who pays development charges and permit fees |
How to use it when comparing quotes
- Send the same specification schedule to every builder with the drawings.
- Ask each to mark what they changed, and why.
- Compare line by line. A lower price with a lower spec is not a lower price.
- Where a builder has used an allowance, ask whether it is realistic; the allowance guide shows how to shop one.
- Attach the final version to the contract and reference it in the contract’s scope clause. The scope of work page explains the wording.
The lines people leave blank, and regret
- Window brand and glazing (the difference between lines is thousands)
- Insulation values, especially the slab and the attic
- The heating system size and who did the heat loss
- Stone and brick extent, because “front elevation” means different things
- Pot light count and fixture allowance
- Driveway surface
- Who pays the development charges
Related guides on this site
Sources and further reading
Questions people ask
What is a specification schedule in a building contract?
A trade-by-trade list of exactly what is included in the price: materials, grades or brands, quantities where they matter, and allowances for items not yet chosen. It is attached to the contract and governs what "included" means.
How do I compare builder quotes fairly?
Give every builder the same drawings and the same specification schedule, and have them mark changes. Then compare line by line; a lower price built to a lower spec is not cheaper.
What goes in an allowance versus a specification?
A specification names the item; an allowance budgets for one not yet chosen. Keep allowances few and realistic, and list them all in one place with what each covers and the markup on overages.
Does the specification override the drawings?
The contract should say which governs when they conflict. Usually the specification governs materials and the drawings govern dimensions; say so in the contract.
Before you sign anything
Run the contract through our free checker; it flags the clauses that cause most of the arguments we get called about. Building with us? The contract comes with the clauses already in it.
Reviewed and updated October 2026. Costs are Ontario ranges, not quotes; code references are to the Ontario Building Code in force at that date.

