Extensions in Seaford: design, planning and build
From a small utility to a two-storey addition, we take on house extensions throughout Seaford, starting with a free visit and a planning check.
- Postcode districtsBN25
- Price regionSouth East England (×1.12)
- Planning rulesEngland
- Site visitFree, no obligation
Do extensions in Seaford 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 Seaford
Our survey diary covers Seaford, including BN25. Nearby, we also take on projects in Peacehaven (5 miles), Eastbourne (8 miles), Hailsham (9 miles), Brighton (11 miles), Hove (12 miles). For homes towards West Sussex, Burgess Hill is around 17 miles away.
Popular extension prices in Seaford
Every figure below is a guide for Seaford, 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) |
|---|---|---|
| Kitchen extensions | 20 m² | £47,000 – £59,500 |
| 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 |
| Wraparound extensions | 25 m² | £64,000 – £81,500 |
Which extension suits a Seaford home?
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, double-storey extensions and wraparound extensions are often the strongest options, with orangery extensions worth considering where there is room.
Choose an extension type
- Single-storey rear extensions · from £23,500
- Double-storey extensions · from £42,500
- Conservatory replacement extensions · from £22,000
- Building regulations for extensions · from £1,000
- Side return extensions · from £20,000
- Annexe extensions · from £61,500
- Home office extensions · from £17,500
- Wraparound extensions · from £40,000
- Orangery extensions · from £33,500
- Flat roof extensions · from £23,500
- Timber frame extensions · from £23,500
- Glass box extensions · from £33,500
- Bedroom extensions · from £29,000
- Bungalow extensions · from £29,000
- Porch extensions · from £4,450
- Pitched roof extensions · from £24,500
- Kitchen extensions · from £30,000
- Extensions over a garage · from £26,500
- Planning permission for extensions · from £350
- Extension plans and drawings · from £1,300
- Side extensions · from £24,500
- Utility and boot room extensions · from £15,500
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 draw the design, agree it with you and handle planning or permitted development checks and building regulations.
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions about extensions in Seaford
How much does an extension cost in Seaford?
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.
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.
Do I need planning permission for an extension in Seaford?
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.
Book a free site visit in Seaford
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.