Why do cost-per-square-foot numbers vary so much?

Because they bundle everything: foundation type, ceiling heights, window count, finish level and local labor rates. Two 2,000 sq ft homes can legitimately differ by 60% in cost.

Does this include the land?

No. It covers hard construction costs plus permits and contractor overhead. Land, site work, utility connections, landscaping and financing are separate line items.

How much contingency should I carry?

Ten percent for new construction on a clean site, fifteen to twenty percent for renovations or anything involving an existing structure where hidden conditions are likely.

Why are additions more expensive per square foot than new homes?

Additions require tying into an existing structure, matching finishes, protecting occupied space and working in tighter conditions, all of which reduce crew efficiency.

Can I use this for a bank or investor pro forma?

Use it for early feasibility only. Lenders will want a contractor's itemized bid or a professional cost estimate before funding.

Renovation & Estimation

Construction Cost Estimator

US and Canada cost ranges and per-square-foot pricing.

Inputs

Given

Project size

sq ft

Project type

Material grade

Region

Country

Rate source

Contingency

Results

Computed

Estimated project cost (USD)

$283,866 – $400,752

Midpoint $333,960 · $152 per square foot

Base construction cost$303,600

Contingency reserve$30,360

Midpoint total$333,960

Materials (approx. 42%)$140,263

Labor (approx. 40%)$133,584

Permits & fees (approx. 6%)$20,038

Overhead & profit (approx. 12%)$40,075

Cost per square foot$151.80 / sq ft

Project size2,000 sq ft

Figures are shown in USD and built from United States published averages with a regional multiplier. Canadian and US rates are independent local averages, not currency conversions of each other. Site conditions, foundation type, and current material pricing can move a real bid well outside this band. Always get itemized quotes from licensed contractors.

Sources & assumptions

RSMeans / industry averages — US construction costsAs of 2025-01-01 — US national-average construction cost data used as a baseline for American projects.

$283,866 – $400,752 · $152/sq ft USD

How this is calculated

Preliminary construction budgets are built from a cost per square foot, adjusted for what you are building, how it is finished, and where it is being built:

cost/sq ft = base rate × grade factor × regional factor

base cost = square footage × cost/sq ft

A contingency reserve is then added on top, because almost every project encounters something unforeseen once walls are open or soil is tested:

total = base cost × (1 + contingency ÷ 100)

The range shown spans roughly 15% below to 20% above the midpoint, which reflects the normal spread of competitive bids on the same set of plans. The split into materials, labor, permits and overhead follows typical industry ratios: materials and labor each account for around 40% of hard costs, with permits, insurance, supervision and contractor profit making up the rest.

Worked example

Budgeting a 1,600 sq ft addition in Ontario

Published Canadian base rate for an addition: $320 CAD per sq ft at standard grade.
Ontario regional factor 1.14× → $365 per sq ft.
Base cost = 1,600 × 365 ≈ $584,000.
With 10% contingency the budget lands near $642,000, before sales tax.
The printed range (±15–20%) — roughly $515,000 to $770,000 — is the honest planning envelope until you hold real quotes.

Common mistakes

Treating the estimate as a quote
This is a planning range from published data, not a bid. Site access, foundation conditions and current material pricing routinely move a real quote outside any published range.
Forgetting soft costs
Design fees, permits, surveys and financing costs typically add 8–15% on top of hard construction costs. The estimator covers construction; carry soft costs separately.
Using the wrong region factor
Construction pricing varies more within a country than between project types. A Toronto build and a rural Nova Scotia build differ by roughly 30% for identical scope.