A bad builder can cost you far more than a good one ever would. Unfinished work, disappearing deposits, and shoddy jobs that need redoing — these are the nightmare scenarios that appear regularly in UK consumer news. But the UK does have excellent tradespeople, and finding one isn't as hard as it seems if you know what to look for. Here's exactly what to check before you hand over a single penny.
Where to Find Builders in the UK
Word of mouth is still the best source. Ask neighbours, friends, or family who have had renovation work done recently. A personal recommendation from someone whose taste and standards you trust is worth more than any rating on a website.
Federation of Master Builders (FMB). The FMB is the UK's largest trade association for the building industry. Members are independently inspected and must meet quality and financial standards. Search at fmb.org.uk.
Checkatrade and Rated People. Both platforms allow you to search by trade and location, read verified reviews, and see ratings for quality, reliability, and tidiness. They're useful for smaller jobs and for getting an initial shortlist — but reviews alone aren't sufficient due diligence.
TrustMark. A government-endorsed quality scheme covering most home improvement trades. Tradespeople registered with TrustMark have agreed to operate to required standards and have their work monitored.
Local trade directories and community Facebook groups. Hyperlocal Facebook groups (search "[your town] recommendations") often produce the most candid feedback on local tradespeople — people are more honest with their neighbours than on public-facing review platforms.
10 Things to Check Before You Hire
1. Are they properly insured? Any builder working on your property must have public liability insurance (minimum £1 million, ideally £2–5 million). Ask for a copy of the certificate and check the expiry date. Without this, you could be liable for accidents that happen on your property.
2. Can they provide references from recent jobs? Ask for at least two or three references from clients whose work is similar in scope to yours, completed within the last 12 months. Follow up and actually call them. Ask: did they finish on time? Did the final cost match the quote? Would you hire them again?
3. Can you see previous work in person? A confident, professional builder should have no hesitation letting you visit a completed project. Seeing the quality of finishes, joinery, or plastering first-hand tells you far more than photos.
4. Are they VAT registered? For significant projects (typically over £10,000–£15,000), a builder who isn't VAT registered may be operating below the threshold or working largely in cash. While not automatically a red flag, it's worth understanding their business scale. VAT registration can be verified on the HMRC website.
5. Are they a sole trader or a company? Understanding the business structure matters for accountability. A limited company has different legal obligations than a sole trader. Check the company number on Companies House if they're registered as a limited company — it takes 30 seconds and confirms they exist.
6. Do they provide a detailed written quote? Never accept a verbal quote or a vague single-line estimate. A proper quote should itemise: materials, labour, timescale, payment schedule, and what's excluded. If something isn't written down, it doesn't exist.
7. What's the payment structure? A professional builder will typically ask for a small deposit (10–20%) upfront, with staged payments tied to completed milestones. Be very wary of anyone asking for more than 30% upfront or demanding large cash payments. Stage payments protect both parties.
8. Do they use subcontractors, and who are they? Many builders subcontract specialist work — plastering, electrics, plumbing. That's normal. But you should know who will be on your site, and whether those subcontractors are also insured. Ask upfront.
9. Is there a written contract? For any project over a few thousand pounds, a written contract is essential. It should cover scope of works, materials spec, start and completion dates, payment schedule, variation procedure, and what happens if there's a dispute. The FMB provides a free contract template for its members.
10. What's their dispute resolution process? Reputable builders — especially FMB or TrustMark members — have access to independent dispute resolution if something goes wrong. Ask how they'd handle a disagreement about workmanship before you start, not after.
Red Flags to Walk Away From
- Pressure to decide immediately or accept a cash-only discount
- No fixed address or business history you can verify
- Unwilling to provide references or show previous work
- Quotes significantly lower than everyone else (it usually means corners will be cut)
- Asks for large upfront payment before work begins
- Uses vague or verbal-only agreements
- No public liability insurance
Managing Your Builder Once Hired
Even a good builder needs clear communication to deliver the job you want.
Keep a site log. Note what work was done each day, any materials delivered, and any issues raised. This protects you if there's a dispute later.
Agree a variation process. Any change to the agreed scope — even small ones — should be confirmed in writing with a cost and time impact. Unwritten variations are the most common cause of disputes.
Do a snagging walk-through before final payment. Walk through the completed work with your builder before paying the final instalment. List anything that isn't right. Only release the final payment when you're satisfied.
Withhold a retention. For larger projects, it's reasonable to hold back 2.5–5% of the final payment for 3–6 months after completion. This gives you leverage if defects appear. Agree this upfront in the contract.
For a deeper guide covering FMB vs TrustMark vetting, the JCT Minor Works contract, and dispute resolution, see our how to find a reliable builder UK guide. For a clear explanation of the build sequence — what first fix and second fix mean for electrics, plumbing, and carpentry, and why the order matters — see our first fix vs second fix guide.
- Renovation Cost Contingency: How Much to Budget and Why — how much to set aside for unexpected costs once you've hired, what contingency should cover, and how to protect the fund from being spent too early
- When to Use a Project Manager vs Manage Your Own Renovation — once you've found a builder, decide whether to self-manage or bring in a PM for the 10–15% fee