House Extensions in Muswell Hill
Trusted local builders for homeowners across Muswell Hill and North London. Clear written quotes, honest timelines, and a finished extension you'll be proud of.
- Initial site survey and feasibility assessment
- Permitted Development advice (or planning application management where required)
- Structural drawings and engineer's calculations
- Building Regulations application and inspections
- Full groundworks and foundations
- Structural steelwork and masonry
- Roof structure, weatherproofing and insulation
- Windows, doors and glazing (bi-fold, patio or French)
- First and second fix electrics and plumbing
- Plastering, screeding and internal finishing
- Building Control completion certificate
If you're planning a house extension in Muswell Hill, you want a builder who knows the area, knows the properties, and won't leave you guessing at every stage. Muswell Hill's Edwardian and Victorian terraces and semis have their own quirks — from shallow footings to limited rear access — and the right builder spots those early rather than mid-build.
Lavington Build works with homeowners across Muswell Hill, Crouch End, Highgate, East Finchley and Alexandra Park. We handle everything from the initial survey through to Building Control sign-off, so you have one team and one point of contact from start to finish.
We give you a fixed written quote before any work starts. No day rates, no open-ended estimates, no bill shock at the end.
Muswell Hill (N10), Crouch End, Highgate, East Finchley, Alexandra Park, Fortis Green, Wood Green, Bounds Green
Fixed written quotes. Labour and materials itemised separately. What you're quoted is what you pay.
One team, start to finish. Same team from foundations to finishing. No revolving door of subbies.
Building Regulations handled. We manage Building Control from application to completion certificate.
Proper surveys before quoting. We visit the site before quoting — Victorian terraces often have surprises below ground.
Fully insured. Public liability cover on every project.
How much does a house extension cost in Muswell Hill?
Between £1,500 and £2,500 per square metre. A single-storey rear extension of around 20 sq m usually comes in at £30,000–£50,000 including groundworks, build and standard finish.
Do I need planning permission for an extension in Muswell Hill?
Most single-storey rear extensions fall under Permitted Development. However Muswell Hill has conservation areas and Article 4 directions — we check your specific address during the free survey.
How long does a house extension take?
A typical single-storey extension takes 10 to 16 weeks from groundworks to handover. Double-storey extensions run 18 to 24 weeks.
Does an extension add value in Muswell Hill?
Yes — typically 10–20% added to property value. Getting Building Control sign-off is essential to realise this at sale.
Ready to get your extension started? We cover Muswell Hill, Crouch End, Highgate, East Finchley and surrounding North London areas. We reply within 1 working day.