Is CAR insurance compulsory?

Not legally but JCT contracts require it. Without it, a fire or flood mid-build means you absorb the cost.

Do I need a structural warranty for a small extension?

Not for <£30,000 single-storey rear under PD. For double-storey, large or sale-targeted extensions and remortgaging — yes, recommended.

Will my home insurance cover the works?

Usually not above a low threshold (£15,000–£50,000). Notify your insurer; they will either add a rider, refer you to a specialist, or void cover if not notified.

Does Builderr arrange insurance?

Yes — we hold £5m PL and £10m EL; CAR arranged under JCT clause 6.4; warranty broker referrals for NHBC/LABC where required.

Quick Answer

What Insurance Do I Need for a London Renovation?

Q: Do I need a structural warranty for a small extension?

Not for <£30,000 single-storey rear under PD. For double-storey, large or sale-targeted extensions and remortgaging — yes, recommended.

Q: Will my home insurance cover the works?

Usually not above a low threshold (£15,000–£50,000). Notify your insurer; they will either add a rider, refer you to a specialist, or void cover if not notified.

Q: Does Builderr arrange insurance?

Yes — we hold £5m PL and £10m EL; CAR arranged under JCT clause 6.4; warranty broker referrals for NHBC/LABC where required.

For a London renovation: builder carries £5m public liability + £10m employers' liability (mandatory if subcontractors). Client should hold contractors all-risk insurance (CAR) covering the works in progress (£200–£600 premium on £100,000 project) and notify home insurer about the works. New-build extensions over £30,000 typically need structural warranty (NHBC, LABC, Premier Guarantee) — £900–£2,400.

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Builder's insurance

Public liability £5m minimum (covers damage to neighbour's property, public). Employers' liability £10m (mandatory by law if any subcontractors/employees on site). Builder should provide certificates at tender. JCT contract requires builder to maintain these throughout build. Check certificates aren't expired — common builder oversight.

Client's insurance

Contractors all-risk (CAR): covers the works in progress, materials on site, fire/flood/theft during construction. £200–£600 on £100,000 project. Often arranged by builder under JCT (clause 6.4); alternatively client takes out separately (clause 6.5C in JCT MW). Notify home insurer — most home policies have exclusions during works over £15,000–£50,000; you may need a renovation rider or move to a specialist insurer (Renovation Plan, Self Build Zone).

Structural warranty (new builds and extensions)

NHBC, LABC Warranty, Premier Guarantee, BLP — 10-year structural warranty on new builds and major extensions. Required for mortgage approval on remortgages or sale. £900–£2,400 for typical extension; £2,500–£6,500 for new build. Builder must be registered with the warranty provider. Required on all sale-friendly extensions.

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