Extending your home in Finchley
Looking to extend your home in Finchley? Start here: extension types, guide prices for Finchley, the planning rules that apply and how a project runs.
- Postcode districtsN2, N3, N12, NW4, NW7, NW11
- Price regionLondon (×1.3)
- Planning rulesEngland
- Site visitFree, no obligation
Popular extension prices in Finchley
Use these Finchley guide prices to sense-check a budget; the guide-price tool narrows them to your own size, and the site visit turns them into a written figure.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Conservatory replacement extensions | 14 m² | £39,000 – £50,500 |
| Extensions over a garage | 12 m² | £32,500 – £42,500 |
| Single-storey rear extensions | 20 m² | £53,000 – £68,000 |
| Orangery extensions | 16 m² | £58,000 – £73,000 |
| Double-storey extensions | 32 m² | £74,500 – £98,000 |
| Side return extensions | 11 m² | £34,000 – £43,000 |
| Wraparound extensions | 25 m² | £74,500 – £94,500 |
Planning and building control in Finchley
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Covering Finchley and nearby
Postcode districts we cover around Finchley include N2, N3, N12, NW4, NW7, NW11. Nearby, we also take on projects in Golders Green (2 miles), Friern Barnet (2 miles), Muswell Hill (2 miles), Cricklewood (3 miles), Kilburn (3 miles). For homes towards Hertfordshire, Borehamwood is around 5 miles away.
Which extension suits a Finchley home?
In London, space is at a premium and gardens are often short, so side returns, wraparounds and carefully planned rear extensions tend to make the most of every metre.
Depending on the plot, kitchen extensions and wraparound extensions are often the strongest options, with side return extensions worth considering where there is room.
All extension types we build in Finchley
- Extension plans and drawings · from £1,550
- Kitchen extensions · from £35,000
- Pitched roof extensions · from £28,500
- Single-storey rear extensions · from £27,000
- Side extensions · from £28,500
- Conservatory replacement extensions · from £26,000
- Annexe extensions · from £71,500
- Bedroom extensions · from £33,500
- Bungalow extensions · from £34,000
- Building regulations for extensions · from £1,150
- Porch extensions · from £5,200
- Extensions over a garage · from £31,000
- Timber frame extensions · from £27,000
- Home office extensions · from £20,500
- Orangery extensions · from £39,000
- Flat roof extensions · from £27,000
- Utility and boot room extensions · from £18,000
- Side return extensions · from £23,000
- Wraparound extensions · from £46,500
- Planning permission for extensions · from £450
- Double-storey extensions · from £49,000
- Glass box extensions · from £39,000
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions about extensions in Finchley
How much does an extension cost in Finchley?
Using our London factor (×1.3), a standard-spec single-storey extension of 20 m² is a guide £53,000 to £68,000 including VAT, and a 32 m² two-storey extension £74,500 to £98,000. Your written price follows the survey.
How long does an extension take in Finchley?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Do I need planning permission for an extension in Finchley?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Finchley, and the guide-price tool gives a range for your own size and finish in about a minute.
Who do I contract with?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Book a free site visit in Finchley
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.