House extensions in Horley
We design and build house extensions for homes in Horley and the surrounding Surrey area, with guide prices adjusted for the region.
- Postcode districtsRH6
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
What extensions cost in Horley
Every figure below is a guide for Horley, 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) |
|---|---|---|
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
| Conservatory replacement extensions | 14 m² | £33,500 – £43,500 |
| Orangery extensions | 16 m² | £50,000 – £63,000 |
| Side return extensions | 11 m² | £29,500 – £37,000 |
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
| Extensions over a garage | 12 m² | £28,000 – £36,500 |
Planning and building control in Horley
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.
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).
What works best for Horley 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.
Depending on the plot, single-storey rear extensions and wraparound extensions are often the strongest options, with double-storey extensions worth considering where there is room.
Where we work near Horley
Postcode districts we cover around Horley include RH6. We also work in nearby Redhill (5 miles), Reigate (5 miles), Caterham (8 miles), Banstead (10 miles), Leatherhead (11 miles). For homes towards West Sussex, Crawley is around 4 miles away.
All extension types we build in Horley
- Building regulations for extensions · from £1,000
- Bungalow extensions · from £29,000
- Kitchen extensions · from £30,000
- Wraparound extensions · from £40,000
- Timber frame extensions · from £23,500
- Extension plans and drawings · from £1,300
- Utility and boot room extensions · from £15,500
- Side extensions · from £24,500
- Glass box extensions · from £33,500
- Porch extensions · from £4,450
- Flat roof extensions · from £23,500
- Planning permission for extensions · from £350
- Orangery extensions · from £33,500
- Side return extensions · from £20,000
- Bedroom extensions · from £29,000
- Extensions over a garage · from £26,500
- Conservatory replacement extensions · from £22,000
- Single-storey rear extensions · from £23,500
- Home office extensions · from £17,500
- Annexe extensions · from £61,500
- Double-storey extensions · from £42,500
- Pitched roof extensions · from £24,500
Free site visit
We visit your Horley home, measure up, talk through what you want and check the planning position.
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
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
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 Horley
How much does an extension cost in Horley?
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 I need planning permission for an extension in Horley?
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.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Do you cover all of Horley?
Yes, including the surrounding parts of Surrey. 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 Horley, and the guide-price tool gives a range for your own size and finish in about a minute.
Book a free site visit in Horley
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.