Home project comparison

Tell us about your extension.

Get a personalised cost estimate, understand whether you may need planning permission, and see your next steps—all tailored to your home and council.

A few short steps No phone or email needed for the estimate Free early estimate

UK-wide private beta: local cost context and nation-specific guidance. The team reviews help requests first.

Step 1 of 5Your early estimate

What would help you today?

Estimate my costsAn early budget, even without plansHelp me planUnderstand the route and next stepsI already have plansCheck what is still missing

Your project

What are you hoping to build?

Choose the closest match. You can refine it later without starting again.

Single-storey rearKitchen, dining or family-room extensionTwo-storey extensionMore space downstairs and upstairsSide or wraparoundSide-return or combined side and rearLoft conversionRooflights, dormer or hip-to-gableGarage conversionTurn an existing garage into living spaceNew home or otherA new dwelling or a larger bespoke project

Transparent guidance

See what the estimate is based on.

England planning guidance Planning Portal extension rules Find your council / planning office 2026 build-cost benchmark