Builder advice in London
London buyers face a property market where the asking price rarely tells you what you're really getting. A two-bed in Clapham could be a structurally sound Victorian conversion or a poorly executed loft split with no Building Regs sign-off. Leasehold flats add another layer: service charges, major works Section 20 notices, and cladding remediation that may or may not be funded. Most London buyers we speak to have already paid for a RICS Level 2 and still don't know whether the £18k 'historic movement' note means £2k of monitoring or £40k of underpinning.
Popular Areas in London
Looking for an independent builder near you in London to review a survey or quote? We translate jargon into pounds, room by room — from period terraces to high-rise leasehold flats — so you don't overpay in the capital.
We provide builder advice across London including Clapham, Brixton, Shoreditch, Hackney, Stratford, Canary Wharf, Wimbledon, Richmond, Islington, Camden, Tooting, Walthamstow, Peckham, Greenwich, Ealing, Battersea.
Our experienced builders provide independent property advice for buyers in London and across Greater London. With 25+ years of construction experience, we identify hidden issues that standard surveys miss. Consultations from £59.
Services include: property inspection before buying, first-time buyer consultations, renovation cost estimates, structural assessments, and builder quote reviews.
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Local building insights for London
- Victorian and Edwardian terraces across Clapham, Tooting and Walthamstow often have rear-extension cracking and original lath-and-plaster ceilings — we cost the realistic repair list before you offer
- Ex-local-authority flats in Southwark, Lambeth and Hackney may carry post-Grenfell cladding, EWS1 and fire-door obligations — we explain the service-charge impact in plain English
- Basement and lower-ground conversions across Chelsea, Islington and Camden need proper tanking, sump pumps and party-wall awards — we verify what\
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- Loft conversions and side returns are everywhere — we check building-control sign-off, steel sizing and Party Wall Act compliance before completion
- Conservation areas (Hampstead, Greenwich, Bedford Park, Bloomsbury) restrict windows, render and roof finishes — we advise what you can and can\
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Common property issues in London
Victorian conversion structural alterations
Walls knocked through in 1990s flat conversions often lack steel calcs or Building Regs completion. We see chimney breasts removed at first-floor level with no gallows brackets — a £6–12k retrofit if a future buyer's surveyor flags it.
Section 20 major works exposure
Leaseholders can be billed tens of thousands for roof, lift or window works decided after exchange. Always ask for the last 3 years of service-charge accounts and any Section 20 consultation notices in progress — not just the headline charge.
Cladding and EWS1 status
Mid-rise blocks built 1995–2018 may still need remediation. An A1/B1 EWS1 is fine; B2 means the building has combustible cladding and your mortgage offer can collapse. Check the form, not the agent's reassurance.
Basement and lightwell damp
Garden-flat kitchens extended into the rear lightwell often rely on tanking that has failed. Look for fresh paint at skirting level and ask when the tanking was installed — most systems are warrantied 10–20 years.
Realistic renovation costs in London
| Job | Typical cost | Worth knowing |
|---|---|---|
| Full flat rewire (2-bed conversion) | £5,500 – £9,000 | London labour premium; add for ornate cornicing reinstatement. |
| New kitchen, mid-spec | £12,000 – £22,000 | Building management approval often needed for waste re-routing. |
| Bathroom refit with waterproofing | £7,000 – £14,000 | Leasehold flats: leak risk is on you — overspec the tanking. |
| Single-storey rear extension (4m) | £55,000 – £95,000 | Excludes party wall awards (£1,500–£3,000 per neighbour). |
| Loft conversion (dormer) | £60,000 – £110,000 | Add £4–8k if steels need craning through the front. |
Planning quirks that catch buyers out
- Most inner-London boroughs have Article 4 directions removing permitted development rights in conservation areas — even rooflights can need consent.
- Party Wall Act notices are non-negotiable for any work on a shared wall; budget £1,500–£3,000 per adjoining owner if surveyors are appointed.
- Basement extensions face borough-specific caps (Kensington & Chelsea, Westminster, Camden all differ) — check the local plan before offering on a property marketed with 'basement potential'.
- Listed buildings need Listed Building Consent for internal as well as external changes — including replacement boilers in some cases.
Clapham two-bed conversion, £40k structural surprise avoided
A first-time buyer was about to exchange on a £625k garden flat in Clapham. The Level 2 survey flagged 'evidence of past structural alterations' with no further comment. On a 30-minute call we walked through the photos and pointed out a removed chimney breast at first floor with no visible gallows bracket. The buyer instructed a structural engineer who confirmed it needed retrofit support. The seller agreed to fund the works pre-completion.
Result £12,000 contribution from seller
London property is too expensive to buy on a surveyor's hedged wording alone. A short call with an independent builder before exchange can turn 'evidence of historic movement' into a clear decision: proceed, renegotiate, or walk.
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