Extensions in Brighton: design, planning and build
Every type of house extension in Brighton, from single-storey kitchen extensions to two-storey additions, side returns and orangeries. We design, handle the approvals and build.
- Postcode districtsBN1, BN2, BN3, BN41
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Which extension suits a Brighton 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 orangery extensions, double-storey extensions and single-storey rear extensions: between them they cover most of the layouts we see requested for houses like these.
Guide prices for Brighton
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) |
|---|---|---|
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
| Side return extensions | 11 m² | £29,500 – £37,000 |
| Orangery extensions | 16 m² | £50,000 – £63,000 |
Do extensions in Brighton need planning permission?
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).
Where we work near Brighton
Postcode districts we cover around Brighton include BN1, BN2, BN3, BN41. The same team covers Hove (1 mile), Portslade (3 miles), Peacehaven (6 miles), Seaford (11 miles), Uckfield (14 miles), all within easy reach. For homes towards West Sussex, Shoreham-by-Sea is around 6 miles away.
Extension types and starting prices
- Double-storey extensions · from £42,500
- Home office extensions · from £17,500
- Extensions over a garage · from £26,500
- Extension plans and drawings · from £1,300
- Flat roof extensions · from £23,500
- Annexe extensions · from £61,500
- Kitchen extensions · from £30,000
- Pitched roof extensions · from £24,500
- Side extensions · from £24,500
- Single-storey rear extensions · from £23,500
- Conservatory replacement extensions · from £22,000
- Building regulations for extensions · from £1,000
- Bedroom extensions · from £29,000
- Side return extensions · from £20,000
- Planning permission for extensions · from £350
- Orangery extensions · from £33,500
- Bungalow extensions · from £29,000
- Porch extensions · from £4,450
- Utility and boot room extensions · from £15,500
- Glass box extensions · from £33,500
- Timber frame extensions · from £23,500
- Wraparound extensions · from £40,000
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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 Brighton
How much does an extension cost in Brighton?
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 Brighton?
Yes, including the surrounding parts of East Sussex. Site visits are free and there is no obligation.
Do I need planning permission for an extension in Brighton?
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.
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 Brighton
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.