Covering Finchley
Finchley sits 7 miles north-west of London, with Muswell Hill 2 miles to the east and Cricklewood 3 miles to the south.
Homes in London
Terraced houses dominate many London neighbourhoods, so most projects involve shared walls, narrow access and a party wall process. Conservation areas are widespread, and some boroughs have their own mansard and basement guidance.
What do you get with an upward extension?
The first question is whether the existing walls and foundations can carry the extra load, so we start with a structural survey. Then we design either a full first floor or a raised roof with dormers, handle planning or prior approval, and build the new storey while protecting the floor below.
- Structural survey of walls and foundations
- Roof removal and temporary weather protection
- New first-floor structure, walls and roof
How much should I budget for an upward extension?
Guide prices for bungalow and upward extensions, including VAT where it applies. Your fixed price is confirmed in writing after the survey.
| Bungalow and upward extensions | Guide price incl. VAT |
|---|---|
| Chalet conversion with dormers (total) | £45,000 to £85,000 |
| New first floor, standard specification | £2,200 to £2,800 per m² |
| New first floor, good specification | £2,800 to £3,300 per m² |
| New first floor, high specification | £3,300 to £3,800 per m² |
Planning and building rules in Finchley
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.
In England, Class AA permitted development allows an extra storey on many detached and semi-detached houses built between July 1948 and October 2018, subject to a prior approval application covering design, neighbours’ amenity and other matters. Houses in conservation areas and other protected land need full planning permission, as do most chalet conversions with front dormers.
What should I think about before starting?
- The house is exposed while the roof is off, so the sequence is planned tightly.
- Neighbours’ light and privacy are the main planning tests.
How does the project run?
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
What people ask before starting
Do we need to move out?
Often for part of the job, while the roof is off and the new floor is formed. We plan this with you.
How long does it take?
About 12 to 24 weeks on site.
Can you visit a house in Finchley to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Also covering
- Bungalow and upward extensions in Muswell Hill
- Bungalow and upward extensions in Cricklewood
- Bungalow and upward extensions in Kilburn
- Bungalow and upward extensions in Wood Green
Learn more about bungalow and upward extensions, or see every project we cover in Finchley.

