Free resource · 31 points
London builder vetting checklist.
The same 31-point checklist Builderr uses to assess subcontractors before adding them to our supply chain. Free, no email required, shareable. Print and tick through every quote you receive.
1. Insurance and trade bodies
- Public liability insurance £5m+ — request certificate.
- Employers' liability insurance £10m+ — request certificate.
- Contractors all-risks insurance for the project value.
- Trade body membership (FMB, NHBC, TrustMark, Chartered Building Company).
- Companies House registration — confirm dates, directors, accounts filed.
- VAT registration confirmed against HMRC if quote includes VAT.
2. References and track record
- Minimum 3 recent references on similar-size projects in your borough.
- Visit at least one completed project in person.
- Speak to clients by phone, not email — written references are easy to fake.
- Check Google reviews, Trustpilot and Houzz independently.
- Ask references about variations, communication and final cost vs quote.
3. Quote structure
- Fully itemised bill of quantities, line by line.
- Fixed-price, fixed-scope — no day-rate drift on projects over £20k.
- No provisional sums (PCs) on definable items — those are budget bleed risks.
- Allowances clearly capped and labelled.
- VAT line-itemed (or expressly stated as VAT-exempt if applicable).
- Validity period stated (most quotes valid 30–60 days).
4. Payment schedule
- No upfront payment above 5% deposit on contract signature.
- Industry-standard milestones (5/15/20/20/20/15/5%) tied to deliverables.
- Each milestone signed off by client before invoice issued.
- 5% retention against 6-month defects walk-through.
- Refuse 40%+ upfront 'materials' deposits — that's a cashflow risk on their end.
5. Warranty and aftercare
- 10-year insurance-backed structural warranty (NHBC, Premier Guarantee, LABC).
- 12-month defects liability period included.
- Subcontractor and supplier warranties pass-through.
- Documented aftercare process and contact during warranty period.
6. Planning, regs and survey
- Planning eligibility check at survey stage — PD, Article 4, conservation, listed.
- Lawful Development Certificate (LDC) application included where PD applies.
- Structural calculations from a qualified engineer (IStructE / IMechE / ICE).
- Party wall surveyor coordination and award process included.
- Building control route confirmed (council vs approved inspector) with fees disclosed.