How to choose a builder in Kent

There is no single qualification, membership, or rating that reliably picks out a good builder. The industry is loosely regulated — anyone in the UK can call themselves a builder, register a limited company, and start trading tomorrow. Several of the consumer-facing badges (Trustpilot, Checkatrade, MyBuilder) are pay-to-play marketplaces whose review systems can be gamed and whose vetting is minimal.

The framework that does work is layered: cross-check several independent signals (membership + insurance + Companies House + reference visits + written quote quality), be alert to red flags, and use a proper written contract that protects you if things go wrong. This guide walks through each layer.

Federation of Master Builders (FMB) — the oldest UK trade body. Members are vetted on financial standing, insurance, and references; renewal requires an annual independent inspection of recent work. FMB MasterBond offers a 2-year warranty on completed projects up to £100k. Strongest signal of the lot, in our view, but membership isn't proof of skill — it's proof that the basics have been checked.

TrustMark — government-endorsed quality mark scheme. Members are audited annually on consumer protection, technical competence, and trading practices. Good baseline; less rigorous on technical-skill assessment than FMB.

NHBC (National House Building Council) — focused on new-build housing, offers 10-year structural warranties. Relevant if you're commissioning a new build or substantial conversion; less relevant for extension and refurbishment work.

Federation of Master Builders — Master Bond is the warranty product, distinct from membership.

Guild of Master Craftsmen — older and less rigorous than FMB; useful but not as strong a signal.

Checkatrade, MyBuilder, Trustpilot, Rated People — pay-to-play marketplaces with review systems. Useful as one data point among many; not by themselves a quality signal.

Ask for copies of three current certificates before signing any contract:

Public Liability Insurance — covers damage caused by the builder to your property or third parties. Industry standard is £2 million minimum cover; £5 million is reasonable for larger projects.

Employer's Liability Insurance — legally required if the builder employs anyone (including subcontractors that HMRC treats as employees). Minimum statutory cover is £5 million.

Contract Works / Contractors All Risks Insurance — covers the works in progress against fire, theft, vandalism, and accidental damage. Should be at least the contract value plus 10-20% for materials on site.

Each certificate names the insurer, policy number, expiry date, and cover level. Phone the insurer to confirm the policy is current — takes five minutes and is worth it.

Free at find-and-update.company-information.service.gov.uk. Search the company name or number. Look for:

• Incorporation date — how long has this company traded? Newly-formed limited companies aren't disqualifying (everyone starts somewhere) but if a 30-year-old builder is suddenly trading as a 3-month-old company, ask why.
• Directors and PSCs (persons with significant control) — who actually owns and runs the business? Multiple changes of director in recent years can be a signal.
• Filed accounts — small companies file abbreviated accounts; you can see year-on-year turnover trends and whether the balance sheet is healthy.
• Charges (mortgages, debentures) registered against the company — small businesses sometimes have these for legitimate reasons but heavy charging activity warrants questions.
• Dissolved companies under the same director(s) — a pattern of sibling limited companies being incorporated and dissolved every few years is a phoenix-trading red flag.

Any reputable builder will give you two or three completed-project addresses (with the owners' permission) to visit. Go in person; phone references are easily stage-managed. Without the builder present, ask the owners:

• Did the work come in on the original quoted price, or how much did it change? (Some change is normal; >25% overrun is a warning sign.)
• How was communication — did you always know what was happening this week and next?
• Did they finish? Or did they fade out at the end and leave a snag list to chase for months?
• Did they protect the rest of your house — dust sheets, HEPA vacuums, secured site at end of day?
• Would you use them again? And — separately — would you recommend them to a close friend?
• How long after handover did issues emerge, and how were they handled?

Cash-only or unwilling to provide VAT invoices on work above the VAT threshold (£90,000 turnover in 2026).

Wants a large deposit upfront before any work has started — 10% is reasonable for materials procurement; 30%+ upfront is not.

Won't provide a written quote against a typed specification — verbal quotes leave you exposed.

Pressure-selling tactics: "this price is good for this week only".

Vague about insurance, can't produce certificates within 24 hours of being asked.

Recent Companies House activity that looks like phoenix trading.

Strongly recommends NOT using a contract.

Lots of negative reviews on multiple independent platforms — not just one disgruntled customer.

A serious quote runs to several pages. It identifies the parties, the work, the price, the programme, the payment schedule, and any exclusions clearly. It distinguishes fixed-price items from provisional sums (where the price depends on a choice you'll make later — tiles, taps, kitchen). It states VAT treatment.

Watch out for: lump-sum quotes with no itemisation (you can't tell what's included), vague "to be confirmed" sections on major elements, exclusions buried in small print.

If two quotes for the same work differ by more than 25-30%, the cheaper one is often missing items the dearer one has included. Ask both to clarify against the same itemised scope.

For projects under about £25,000: a plain-letter agreement is usually sufficient if it covers scope, price, schedule, payment terms, dispute resolution, and warranty period.

For projects £25,000-£250,000: JCT Minor Works Building Contract (current edition is the JCT MW 2024) is the industry standard. It allocates risk fairly, sets clear payment terms, and is recognised by every contractor. Available from the JCT website (~£40 per use).

For projects £250,000-£1m+: JCT Intermediate Building Contract or JCT Standard Building Contract. These cover phased payments, variations, named subcontractors, defects liability, and dispute resolution at the scale these projects need.

For new builds: JCT With Quantities or NHBC's Buildmark contract.

A reputable builder will be familiar with these and happy to contract under them. Reluctance to use a recognised standard contract is a serious red flag.

Never pay for work before it's done. Pay in stages tied to physical completion milestones — not to calendar months. Typical structure for an extension:

• 5-10% deposit on contract signature (covers materials procurement)
• 20-25% on completion of foundations and oversite
• 20-25% on completion of structural frame and roof watertight
• 20-25% on completion of first fix (M&E rough, plastering)
• 15-20% on completion of second fix (kitchen, bathrooms, decoration)
• 5% retention held for 12 months against latent defects