Know your real build cost — before you commit
Answer a few simple questions and get a realistic cost range based on UK build data.
- Based on real UK project costs
- Instant results in under 2 minutes
- No sign-up required
Project Types
Choose the calculator that best matches your project.
Home Extension
Plan your extension budget before building
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Loft Conversion
Turn unused space into real value
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Garage Conversion
Convert space into usable living area
Calculate cost →
Internal Renovation
Plan your renovation costs with clarity
Coming SoonHow It Works
Tell us about your project
Type, size, key details
Get your instant estimate
Realistic UK-based cost range
Plan your next steps
Budget and compare options
Latest Guides
Expert advice, cost guides and practical tips to help you plan your project with confidence.
Should I Move or Improve? The Complete UK Homeowner Checklist
Thinking about extending your home or moving to a new one? It's one of the biggest financial decisions most homeowners will ever make. Before requesting builder quotes or booking…
Why the Cheapest Extension Quote May Cost You More
One builder quotes £58,000. Another quotes £52,000. The £52,000 builder looks cheaper—but is it really? Extension quotations can include different assumptions, allowances and…
How to Save ££££s on Your House Extension
Planning a house extension? Discover four practical ways to reduce your extension costs without compromising on the things that matter most.
The Ultimate House Extension Budget Checklist (UK 2026)
Planning a house extension or loft conversion? Use this free budget checklist to avoid unexpected costs before starting your project.
What You’ll Get
- Realistic cost range — not guesswork
- Breakdown of labour & materials
- UK-based pricing benchmarks
- Clear next steps
Built for homeowners making real decisions
- Budget before speaking to builders
- Based on real UK cost data
- No sales pressure
Frequently Asked Questions
How accurate are the estimates?
They are designed as practical budget estimates based on typical UK project costs.
Is BuildCostHub really free?
Yes, homeowners can use the calculator for free with no obligation.
Do I need to create an account?
No, the calculator is designed to be quick and easy to use.
Can I update my estimate later?
You can run another estimate whenever your project details change.