What a custom home costs in the GTA in 2026

Published figures, what they include and what they leave out, and how they become a budget for one house.

Updated November 13, 2026

A house in dark brick and limestone with a deep roof overhang and a tall window onto a lit staircase

Short answer

The Altus Group 2026 Canadian Cost Guide puts the hard construction cost of a custom-built single-family house in the Greater Toronto Area at $500 to $1,130 per square foot. On a 5,000 square foot house that is $2,500,000 to $5,650,000, before land, HST, design fees, permits and development charges.

Hard cost by house size

At the published GTA range of $500 to $1,130 per square foot.

Floor area	At $500 per sq ft	At $1,130 per sq ft
3,000 sq ft	$1,500,000	$3,390,000
4,000 sq ft	$2,000,000	$4,520,000
5,000 sq ft	$2,500,000	$5,650,000
6,000 sq ft	$3,000,000	$6,780,000
8,000 sq ft	$4,000,000	$9,040,000

Floor area as the Canadian Institute of Quantity Surveyors measures it. Hard construction cost only: before land, HST and soft costs. Source: Altus Group, 2026 Canadian Cost Guide, figures as at January 31, 2026.

What the published figure assumes

Hard cost only: The cost of building the house itself.
Average-quality finishes: Unless the guide states otherwise.
A simple site: Stable soil and a level, open site, with nothing next to it that restricts the work.
Measured floor area: As the Canadian Institute of Quantity Surveyors defines it.

What it leaves out

The guide excludes soft costs, taxes and site development. For a custom home, these are the amounts to budget for separately:

The land, and the legal and lender costs of buying and financing it
Design and consultant fees: architect or designer, engineers, surveyor, arborist
Building permit fees and development charges
HST, which is not in the published figures
Site development: demolition of an existing house, servicing, grading and landscaping
Premiums for unusual architecture
A contingency

Why the range is so wide

Finish level: Millwork, stone, windows and fixtures are where custom houses differ most.
Structure: Long spans, steel beams, cantilevers and deep or walk-out basements.
Site: Slope, soil, groundwater, access for trucks and work close to protected trees.
Systems: Heating, cooling, ventilation, electrical and home automation.
Size: Kitchens, bathrooms and mechanical rooms do not shrink with the house, so a smaller house costs more per square foot.
Approvals: Variances, conservation and heritage reviews add design time and fees before construction.

A standard house is a different number

The same guide gives $150 to $275 per square foot for a single-family house with an unfinished basement in the GTA. That row describes a much simpler house. It is useful as a floor, not as a benchmark for a house designed for one lot.

How we price a house

After a first meeting and a look at the lot, we give a budget range. It is refined as the drawings develop: when the structure and systems are known, and again when the permit drawings and selections are complete. Allowances for finishes not yet chosen are listed, so the number can be checked against what is drawn.

Questions

How much does it cost to build a 5,000 square foot custom home in the GTA?

At the published 2026 range of $500 to $1,130 per square foot, the hard construction cost is $2,500,000 to $5,650,000. Land, HST, design fees, permits and development charges are on top.

Is HST charged on a custom home in Ontario?

Yes. HST, at 13% in Ontario, applies to construction and is not in the published figures. Whether a new housing rebate applies depends on the owner and the house, so ask your accountant before the budget is final.

Why do builders quote such different prices for the same house?

Usually because the quotes include different things. Compare what each one allows for finishes, site work, engineering, permits and contingency, and what each one leaves out.

Does the price per square foot include the land?

No. The published figures are hard construction costs only. Land and its legal and financing costs are excluded.

Sources

Checked against these sources on November 13, 2026. This page is general information about building in Ontario. It is not legal advice, and the rules change, so confirm the current requirement for your project.