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Seaford, East Sussex

Rear extension planning drawings in Seaford

We plan and build rear extensions for homeowners in Seaford. Measured survey, design options, planning drawings and the application, handled for you. Start with a free site visit, then a written price once the design is agreed.

Seaford is covered from our East Sussex round, including BN25. Planning applications in Seaford go to the local planning authority covering Seaford, and we check its local design guidance for rear extensions before drawing.

Book a free site visit

Tell us about the house and we'll call to arrange a free, no-obligation visit.

What do rear extension planning drawings cost in Seaford?

As a guide, £1,000–£2,500 including VAT for a single-storey rear extension, or £2,000–£3,500 for a two-storey scheme. A householder planning application in England costs £548 (£575 for applications made from 8 December 2026), and a lawful development certificate for proposed work costs half the householder fee. Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.

Do you need planning permission for a rear extension in Seaford?

The planning route for a rear extension in Seaford is set by England's householder rules and your council.

A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.

Councils aim to decide householder applications within 8 weeks of validation, and prior approval within 42 days.

Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.

What are homes in Seaford like to extend?

Around Seaford the housing ranges from inter-war semis to 1960s and 1970s estates with good-sized gardens. Many of the newer estates had permitted development rights removed by condition, so we check the planning history before anything is drawn.

How a rear extension in Seaford comes together

  1. Free site visit

    We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.

  2. Design and guide price

    Two or three layout options with a guide price for each, so you choose the design knowing what it costs.

  3. Approvals

    Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.

  4. Fixed price and build

    A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.

Rear extension planning drawings near Seaford

We also build rear extensions in nearby Newhaven (2.7 miles) and Peacehaven (5.0 miles).

Other work in Seaford:

All rear extensions in Seaford

FAQ

Rear extension planning drawings questions in Seaford

Is the site visit in Seaford free?

Yes. We visit, measure up and talk through the options with no cost and no obligation.

How long does a rear extension take to build in Seaford?

Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.

Can I see the design in 3D?

Yes; we produce simple 3D views so you can judge the size and light.

Can I get a price without a visit?

Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.

What do rear extension planning drawings cost in Seaford?

As a guide, £1,000–£2,500 including VAT for a single-storey rear extension and £2,000–£3,500 for a two-storey scheme, covering the measured survey, design options and the application. The council fee is extra.

Do you handle building control in Seaford?

Yes. We apply to the council or a registered building control approver and hand over the completion certificate.

Next step

See what your rear extension would cost

Get a guide price online in a couple of minutes, or book a free site visit and we'll measure up and talk you through the planning route.

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