Who drafts the contract?

Usually the builder or contract administrator (architect/surveyor) presents a JCT contract for both to sign. Cost ~£500–£1,200 to administer.

Can I add custom clauses?

Yes — variations of standard JCT clauses are common (e.g., longer defects-liability period, kitchen as PC sum). Best done with a surveyor or solicitor's review.

What if there's no contract and a dispute?

Default to Consumer Rights Act 2015 + Supply of Goods and Services Act. Workable but harder than JCT/FMB resolution.

Does Builderr use JCT?

Yes — JCT Homeowner Contract or JCT Minor Works depending on project size, standard issue on all renovation, extension and loft conversion packages.

Quick Answer

JCT vs FMB Domestic Building Contract: Which to Use in London?

For most London domestic renovations and extensions, use the JCT Homeowner Contract (HOC) or JCT Minor Works (MW) — they have the most robust protections, defined payment schedules, retention provisions and dispute resolution. FMB contracts are good for FMB member projects under £50,000. Avoid ad-hoc 'quotation + email' arrangements on projects over £25,000 — they leave both client and builder exposed.

Full House Renovations →Get a Free Quote

JCT contracts

JCT Homeowner Contract (HOC) — designed for domestic clients, simpler language, suits projects £15,000–£250,000. JCT Minor Works (MW) — more comprehensive, suits £100,000–£750,000 renovations and extensions, includes provisional sums, variation procedures, extension of time, interim payments. JCT Intermediate (IC) — for £500,000+ programmes. All include defined payment schedules, retention (typically 3–5%), defects-liability period (6–12 months) and adjudication dispute resolution.

FMB contract

Federation of Master Builders domestic contract — only available between FMB members and their clients. Lighter-touch than JCT, no retention clause, dispute resolution via FMB. Suits sub-£50,000 projects with FMB-member builders. Weaker on variation control and extension of time than JCT MW.

Why not skip the contract?

Skipping is common but expensive when things go wrong. No payment schedule = disputes about what's due. No variation clause = arguments about extras. No defects-liability period = arguments about who fixes what after handover. Project over £25,000 should have a written contract. Most reputable London builders welcome JCT HOC or FMB contract — refusal is a red flag.

Ready to get started?

Senior consultant call within one business hour. Free desk-based planning assessment. Fixed-scope quote — no provisional sums, no day-rate creep.