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West Sussex

Rear extensions in Shoreham-by-Sea

We design and build rear extensions for homes in Shoreham-by-Sea, West Sussex, from single-storey kitchen-diners across the back of the house to two-storey extensions that add a bedroom above.

Shoreham-by-Sea is in West Sussex, with postcode districts including BN42 and BN43. The nearest places we also cover are Lancing (2.1 miles) and Portslade (2.6 miles).

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

Rear extensions we build in Shoreham-by-Sea

Also available across West Sussex:

Rear extension prices in Shoreham-by-Sea

South East prices run above our West Midlands baseline, mainly on labour rates and clay-soil foundations.

ExampleGuide inc VAT
Single-storey, 3 m × 4 m (12 m²)£25,500–£41,500
Single-storey, 4 m × 6 m (24 m²)£51,000–£83,500
Two-storey, 3 m × 5 m footprint (30 m²)£60,500–£90,500
Side return, about 14 m²£36,000–£59,500
Wraparound, about 25 m²£61,500–£101,000

What are homes in Shoreham-by-Sea like to extend?

Around Shoreham-by-Sea 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.

Planning rules for Shoreham-by-Sea

English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.

If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.

Planning and Building Regulations are separate in England: even a permitted development extension is inspected for foundations, drainage, structure, insulation, fire safety and ventilation, through the council or a registered building control approver, ending with a completion certificate.

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FAQ

Questions people ask

How much is a rear extension in Shoreham-by-Sea?

A 3 m × 4 m single-storey rear extension is about £25,500–£41,500 including VAT at our South East England guide rates; the written price follows a survey.

Do I need planning permission in Shoreham-by-Sea?

Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.

Is the site visit in Shoreham-by-Sea free?

Yes, with no obligation.

Do I need a party wall agreement?

In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.

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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