Extensions in Hailsham: design, planning and build
From a small utility to a two-storey addition, we take on house extensions throughout Hailsham, starting with a free visit and a planning check.
- Postcode districtsBN27
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Areas we cover around Hailsham
Across BN27, we can visit, measure and advise. We also work in nearby Eastbourne (7 miles), Seaford (9 miles), Bexhill-on-Sea (9 miles), Uckfield (10 miles), Peacehaven (12 miles). For homes towards West Sussex, Burgess Hill is around 18 miles away.
Choosing the right extension in Hailsham
Homes across the South East range from Victorian terraces in the older town centres to large detached houses on the edges, so the right extension type varies street by street.
Depending on the plot, orangery extensions and double-storey extensions are often the strongest options, with single-storey rear extensions worth considering where there is room.
Hailsham extension prices at a glance
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) |
|---|---|---|
| Double-storey extensions | 32 m² | £64,500 – £84,500 |
| Side return extensions | 11 m² | £29,500 – £37,000 |
| Single-storey rear extensions | 20 m² | £45,500 – £58,500 |
| Extensions over a garage | 12 m² | £28,000 – £36,500 |
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
Do extensions in Hailsham 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.
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
- Orangery extensions · from £33,500
- Double-storey extensions · from £42,500
- Bedroom extensions · from £29,000
- Glass box extensions · from £33,500
- Annexe extensions · from £61,500
- Building regulations for extensions · from £1,000
- Planning permission for extensions · from £350
- Side return extensions · from £20,000
- Utility and boot room extensions · from £15,500
- Home office extensions · from £17,500
- Wraparound extensions · from £40,000
- Extension plans and drawings · from £1,300
- Porch extensions · from £4,450
- Flat roof extensions · from £23,500
- Kitchen extensions · from £30,000
- Bungalow extensions · from £29,000
- Conservatory replacement extensions · from £22,000
- Side extensions · from £24,500
- Single-storey rear extensions · from £23,500
- Timber frame extensions · from £23,500
- Extensions over a garage · from £26,500
- Pitched roof extensions · from £24,500
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions about extensions in Hailsham
How much does an extension cost in Hailsham?
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.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Do you cover all of Hailsham?
Yes, including the surrounding parts of East Sussex. Site visits are free and there is no obligation.
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 Hailsham
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.