House Construction Cost Calculator
Estimate the cost to build a house from its floor area and local cost per m² or ft², finish level, design and permit fees, contingency and tax — with a typical breakdown by construction stage.
How it works
construction cost = area × cost per unit area × finish factor · fees = construction × fee % · contingency = construction × contingency % · tax = (construction + contingency) × tax % · total = construction + fees + contingency + tax
The quickest way to budget a new house is the cost-per-area (parametric) method used by quantity surveyors: multiply the built floor area by a local cost per m² or ft² for a standard specification, then adjust for the finish level. Professional fees and permits typically add 6–12%, and a contingency of 10–15% covers surprises in the ground and changes during the build. Tax depends on the country and on whether labour and materials are bought separately. Land, demolition, landscaping, furniture and financing costs are not included. The stage breakdown is a typical split for a one- or two-storey masonry or concrete-frame house and varies with design.
Worked example
A 120 m² house at a local cost of $1,000 per m² with a standard finish: construction = 120 × 1,000 = $120,000; fees at 8% = $9,600; contingency at 10% = $12,000; no tax. Total ≈ $141,600, which is $1,180 per m² all-in.
Sources: RICS — New rules of measurement: order of cost estimating (NRM 1) · US Census Bureau — Characteristics of new housing (cost per square foot)
Frequently asked questions
How do I estimate the cost per square metre of a house?
Use recent local prices: ask builders what they charge per m² for your finish level, check your country’s published construction cost index, or divide the final cost of comparable recent houses by their floor area.
How much contingency should I add?
10% for a well-defined design on a known site, 15–20% for renovations, difficult ground or a design that is not finished. It is money you expect to spend, not profit.
What costs are usually forgotten?
Land, utility connections, surveys and soil tests, permits, site clearance, boundary walls, landscaping, kitchen appliances, furniture, financing interest and moving costs.
Which stage of construction costs the most?
The structure (columns, beams and slabs) and the finishes (plaster, floors, paint) are usually the largest parts, each roughly a fifth of the build cost; foundations are around 10%.
Related calculators
This is an order-of-magnitude budget, not a quotation; get itemised quotes from local builders before committing.