House extensions in Farnborough
We design and build house extensions for homes in Farnborough and the surrounding Hampshire area, with guide prices adjusted for the region.
- Postcode districtsGU11, GU14, GU17
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Which extension suits a Farnborough home?
The South East has a broad mix of 1930s semis, post-war estates, newer developments and period cottages, and many houses have enough garden for a generous rear extension.
Start by comparing wraparound extensions, double-storey extensions and single-storey rear extensions: between them they cover most of the layouts we see requested for houses like these.
Areas we cover around Farnborough
We cover Farnborough and the postcode districts GU11, GU14, GU17. Nearby, we also take on projects in Aldershot (3 miles), Fleet (3 miles), Yateley (5 miles), Bordon (13 miles), Alton (14 miles). For homes towards Surrey, Camberley is around 3 miles away.
What extensions cost in Farnborough
Every figure below is a guide for Farnborough, adjusted for South East England build costs (×1.12) and including VAT. Design and council fees are shown separately on each page.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
| Conservatory replacement extensions | 14 m² | £33,500 – £43,500 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Orangery extensions | 16 m² | £50,000 – £63,000 |
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
| Side return extensions | 11 m² | £29,500 – £37,000 |
Planning rules in Farnborough
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 two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
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.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Choose an extension type
- Porch extensions · from £4,450
- Glass box extensions · from £33,500
- Building regulations for extensions · from £1,000
- Annexe extensions · from £61,500
- Extension plans and drawings · from £1,300
- Bungalow extensions · from £29,000
- Wraparound extensions · from £40,000
- Single-storey rear extensions · from £23,500
- Planning permission for extensions · from £350
- Extensions over a garage · from £26,500
- Double-storey extensions · from £42,500
- Home office extensions · from £17,500
- Timber frame extensions · from £23,500
- Flat roof extensions · from £23,500
- Conservatory replacement extensions · from £22,000
- Side return extensions · from £20,000
- Utility and boot room extensions · from £15,500
- Kitchen extensions · from £30,000
- Pitched roof extensions · from £24,500
- Orangery extensions · from £33,500
- Side extensions · from £24,500
- Bedroom extensions · from £29,000
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions about extensions in Farnborough
How much does an extension cost in Farnborough?
Using our South East England factor (×1.12), a standard-spec single-storey extension of 20 m² is a guide £45,500 to £58,500 including VAT, and a 32 m² two-storey extension £64,500 to £84,500. Your written price follows the survey.
Do you cover all of Farnborough?
Yes, including the surrounding parts of Hampshire. Site visits are free and there is no obligation.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Farnborough, and the guide-price tool gives a range for your own size and finish in about a minute.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Book a free site visit in Farnborough
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.