Last Updated on July 19, 2026
Nobody books a £40,000 extension from a Facebook page.
They might find you on Facebook. They might get your name from a neighbour. But somewhere between the recommendation and the deposit, they will sit on the sofa at 10pm and look you up. Your website is not how they find you. It is how they decide not to rule you out.
New to all this? Start with our full guide to how to start a website for your UK business, then come back here for the builder specifics.
The mistake most builders make
They think the website’s job is to generate leads, see that most work comes from word of mouth, and conclude they do not need one.
Wrong job description. For a builder, the website is not a lead generator. It is a background check you get to write yourself.
An extension client spends weeks deciding. They are comparing two or three firms, they have read the horror stories about builders vanishing mid job, and they are looking for reasons to cross names off the list. No website, a dead link, or a template full of stock photos of American houses all read the same way: risk.
What a builder website costs in 2026
Do it yourself. A clean one page site on Wix from around £9 a month or Squarespace from around £12 a month billed annually, domain at £7 to £15 a year. Year one: £120 to £250. At the Start stage, one honest page with five real projects beats a ten page template with none.
A freelancer build. £800 to £3,000, most landing between £1,200 and £2,000, plus £100 to £300 a year running costs. On a trade where the average job is five figures, this is the sensible default.
An agency. £2,500 to £10,000. Only worth discussing if you run multiple crews and need the site feeding a pipeline, not a diary.
Set that against what the job is worth. A typical single storey extension runs £30,000 to £60,000. The website that helps win one is a rounding error on the margin, once.
What the site must show: projects, not promises
Structure the site around real projects, each with its own short page.
Photos that show progress. Footings, steels going in, plastering, the finished room. Progress photos prove the work is yours and show you run a tidy site, which is half of what clients worry about.
A rough cost band and timescale. “Single storey rear extension, around £48,000, eleven weeks” is the single most useful sentence a builder can publish. Nobody else in your area is publishing it, because everyone is scared of being held to it. Add “every job priced individually” and the fear goes away.
What the client said. One named quote per project. Named reviews attached to real jobs are the strongest trust signal in the trade.
Around the projects, cover the basics that survive a background check: your company name matching Companies House, a real address, your insurance stated plainly, and FMB or TrustMark membership with the number written out if you hold it.
What to skip at the Start stage
Skip lead portals selling “extension leads” at £30 to £50 each before your portfolio exists. You will pay to be compared against four other builders on price alone, which is the exact game the portfolio lets you avoid. Skip the blog. Skip the £300 a month SEO retainer. Five project pages and a Google Business Profile first.
The takeaway
Your website will be read by exactly the people about to give you tens of thousands of pounds, at exactly the moment they are deciding whether to trust you. Spend £150 or spend £2,000, but pass the 10pm sofa test: five real projects, real costs, real clients, and a company name that checks out.
Want a straight answer on whether your online presence would survive that check? Whito’s Whito Pro will tell you.
Read next
How to start a website for your UK business in 2026. What it costs, whether you need one at all, what it must contain, and the order to do it in.
