How accurate is this construction cost calculator?

This calculator provides indicative cost ranges based on current UK market rates (2026). Actual costs depend on site conditions, contractor availability, material specifications, and project complexity. We recommend using this as a budgeting starting point, then getting a professional estimate for accurate figures.

Why do costs vary so much between regions?

Labour costs are the primary driver of regional variation. London and the South East have significantly higher labour rates than the North and Wales. Material costs are broadly similar nationwide, but transport and local supplier pricing can also vary.

Does the estimate include VAT?

No — all figures shown are exclusive of VAT. Most construction work on existing residential properties is subject to 20% VAT. New builds may qualify for zero-rated VAT. Always confirm VAT treatment with your contractor.

What is not included in these estimates?

The base estimate excludes professional fees (architect, structural engineer), planning permission costs, furniture, landscaping, and any abnormal site conditions such as contaminated land or poor ground conditions. Use the "Additional Costs" section to add these.

How do I get a more accurate estimate?

Submit your project details to Page Building Consultants. Our experienced estimators will review your drawings and specifications and provide a detailed cost plan within 24 hours — giving you the confidence to approach contractors and manage your budget.

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Last updated: 19 April 2026

UK Construction Cost Calculator

Get an instant indicative cost estimate for your UK construction project. Adjust project type, size, region, and quality level to see a realistic budget range — then get a professional estimate from our team.

Last updated:19 April 2026

Base cost rates, regional multipliers and specification level figures updated to reflect Q2 2026 UK market data.

Next review: July 2026 (Q3)

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1Project Type

2Floor Area

m²

10m²200m²

3UK Region

Regional multiplier: 1× — London costs are typically 35% higher than the national average.

4Specification Level

5Additional Costs(optional)

Select any additional items to include in your total

Estimated Cost Range

Low Estimate

£48,000

High Estimate

£66,000

House Extension • 30m² • Midlands • Standard

Base build cost£48,000 – £66,000

Cost per m²£1,600 – £2,200

Exc. VAT. Indicative range only.

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This calculator gives you a ballpark figure. For a detailed cost plan you can take to contractors, our estimators will review your drawings and deliver a full breakdown within 24 hours.

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How to Use This Calculator

Our UK construction cost calculator uses current 2026 market rates, adjusted for your region and specification level. Here's what each input means.

Project Type

Select the type of construction work. Each project type has different cost drivers — a loft conversion is very different from a new build.

Floor Area (m²)

Enter the gross internal floor area of the project. For extensions, this is the new floor space being added. For refurbs, it's the total area being worked on.

UK Region

Labour costs vary significantly across the UK. London rates are around 35% higher than the Midlands baseline. Select your region for an accurate adjustment.

Specification Level

Standard covers functional finishes. Mid-range adds quality fixtures. Premium covers bespoke joinery, high-end materials, and luxury finishes.

UK Construction Cost Benchmarks 2026

Reference cost ranges per m² for common UK construction project types at standard specification, Midlands baseline. Exc. VAT.

Project Type	Low (£/m²)	High (£/m²)	London Low	London High
House Extension	£1,600	£2,200	£2,160	£2,970
Loft Conversion	£1,400	£2,000	£1,890	£2,700
New Build House	£1,800	£2,800	£2,430	£3,780
Full Refurbishment	£800	£1,600	£1,080	£2,160
Commercial Fit-Out	£900	£2,000	£1,215	£2,700
Groundworks	£200	£600	£270	£810

Source: Page Building Consultants market data. Last updated: 19 April 2026. Figures are indicative and exclude VAT, professional fees, and abnormal site conditions.

Frequently Asked Questions

Everything you need to know about using this construction cost calculator

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Our calculator gives you a starting point. For a detailed cost plan — broken down by trade, with material and labour rates — submit your project to our team. We'll deliver a full estimate within 24 hours.

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