House extensions in Guildford
We design and build house extensions for homes in Guildford and the surrounding Surrey area, with guide prices adjusted for the region.
- Postcode districtsGU1, GU2, GU3, GU4, GU5, GU7
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Planning and building control in Guildford
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).
Guide prices for Guildford
Prices on this page use our South East England factor of ×1.12, include VAT at 20% and cover the build; your written price follows a survey and agreed drawings.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Conservatory replacement extensions | 14 m² | £33,500 – £43,500 |
| Side return extensions | 11 m² | £29,500 – £37,000 |
| Extensions over a garage | 12 m² | £28,000 – £36,500 |
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
What works best for Guildford houses?
In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
Start by comparing double-storey extensions, wraparound extensions and orangery extensions: between them they cover most of the layouts we see requested for houses like these.
Areas we cover around Guildford
Postcode districts we cover around Guildford include GU1, GU2, GU3, GU4, GU5, GU7. The same team covers Godalming (4 miles), Woking (6 miles), Farnham (10 miles), Camberley (10 miles), Weybridge (11 miles), all within easy reach. Aldershot, in Hampshire, is roughly 8 miles from Guildford and also on our list.
Choose an extension type
- Utility and boot room extensions · from £15,500
- Glass box extensions · from £33,500
- Flat roof extensions · from £23,500
- Extension plans and drawings · from £1,300
- Wraparound extensions · from £40,000
- Double-storey extensions · from £42,500
- Kitchen extensions · from £30,000
- Bungalow extensions · from £29,000
- Porch extensions · from £4,450
- Home office extensions · from £17,500
- Single-storey rear extensions · from £23,500
- Side extensions · from £24,500
- Planning permission for extensions · from £350
- Extensions over a garage · from £26,500
- Bedroom extensions · from £29,000
- Side return extensions · from £20,000
- Conservatory replacement extensions · from £22,000
- Orangery extensions · from £33,500
- Annexe extensions · from £61,500
- Timber frame extensions · from £23,500
- Pitched roof extensions · from £24,500
- Building regulations for extensions · from £1,000
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
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
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions about extensions in Guildford
How much does an extension cost in Guildford?
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 handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Do I need planning permission for an extension in Guildford?
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.
How long does an extension take in Guildford?
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.
Book a free site visit in Guildford
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.