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West Sussex

Rear extensions in Lancing

Rear extensions in Lancing: single-storey and two-storey extensions, side returns, wraparounds and glass-led designs, planned around commuter semis and detached houses and the English rules.

Lancing is in West Sussex, with postcode districts including BN15. The nearest places we also cover are Shoreham-by-Sea (2.1 miles) and Worthing (2.4 miles).

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Rear extensions we build in Lancing

Also available across West Sussex:

Rear extension prices in Lancing

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 Lancing like to extend?

Commuter semis and detached houses make up much of Lancing, and longer gardens make England's prior approval route for deeper rear extensions worth considering.

Planning rules for Lancing

In England a single-storey rear extension can often be built under permitted development: up to 3 metres beyond the original rear wall of an attached house, or 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres if any part is within 2 metres of a boundary.

England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.

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 Lancing?

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 Lancing?

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 Lancing 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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