Join our builder network

Win more extension, loft conversion and garage conversion work. Homeowners use ExtensionCosts.co.uk to price their project with our calculator and cost guides, then ask for quotes. We pass those enquiries to vetted local builders who cover their area.

Why join

• Homeowners who already know the cost. Most enquiries come after someone has used our calculator, so they arrive with a realistic idea of what their project costs, not a wish list.
• Useful detail up front. Each enquiry includes the type of project, approximate size, postcode, budget, preferred start date, whether they have drawings, and the estimate our calculator gave them.
• Not shared with a crowd. We tell homeowners their details go to one local builder, so you are not racing five other firms to the phone.
• Only the work you want. Choose the project types, areas and minimum job size that suit your business.

Who we’re looking for

Established builders, loft conversion specialists and design-and-build firms who carry out extensions, loft conversions, garage conversions, conservatories, garden rooms or basements. We check that every firm is properly insured, can show recent similar work and references, and treats customers fairly. Membership of a trade body such as the FMB or TrustMark helps but is not essential.

Register your business

Takes about three minutes. We’ll be in touch within two working days.

Your business

Company or trading name Your name Email Phone Website or Checkatrade profile Optional Companies House number Optional Years tradingChoose oneLess than 2 years2–5 years5–10 years10–20 years20+ years Team sizeChoose oneJust me2–5 people6–15 people16–50 people50+ people

Work you take on

Single storey extensions Two storey extensions Kitchen extensions Side return and wrap-around Loft conversions Garage conversions Conservatories and orangeries Garden rooms Porches Basement conversions Design and build (in-house drawings)

Where you work

London South East South West East of England East Midlands West Midlands Yorkshire and the Humber North West North East Wales Scotland Northern Ireland

Postcode areas you cover

Credentials and capacity

Public liability insuranceChoose one£1 million£2 million£5 million or moreNot currently insured Enquiries you could handle per monthChoose one1–56–1011–20More than 20 Smallest job you take onChoose oneNo minimum£10,000+£25,000+£50,000+£100,000+

Memberships and warranties Tick any that apply

Federation of Master Builders (FMB) TrustMark Checkatrade Which? Trusted Trader NHBC LABC Warranty Premier Guarantee None yet

Anything else we should know? Optional I agree that ExtensionCosts.co.uk may store these details and contact me about joining its builder network. See our privacy policy.

Register my business

Registering is free and does not commit you to anything.

What happens next

1. We review your registration and check your insurance, trading history and recent work.
2. We call you to agree the areas, project types and number of enquiries that suit you, and explain how enquiries are charged.
3. You start receiving enquiries from homeowners in your area, by email and phone.

Registering is free and does not commit you to anything. We will only use your details to contact you about joining our builder network. See our privacy policy.