Essex
Rear extensions in Southend-on-Sea
From the first measured visit to building control sign-off, we handle rear extensions in Southend-on-Sea under one contract.
Southend-on-Sea is in Essex, with postcode districts including SS0, SS1, SS2, SS3 and SS9. The nearest places we also cover are Rochford (3.1 miles) and Hadleigh (4.6 miles).
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
Rear extensions we build in Southend-on-Sea
- Single-storey rear extensions
- Two-storey rear extensions
- Kitchen-diner rear extensions
- Side return extensions
- Wraparound extensions
- Glazed and glass-box rear extensions
- Rear extensions for terraced houses
- Rear extensions for semi-detached houses
- Rear extensions for bungalows
- Rear extension plans and planning applications
Also available across Essex:
- Rear extensions for detached houses
- Flat-roof rear extensions
- Pitched and lean-to roof rear extensions
- Knocking through to a rear extension
- Roof lanterns and rooflights for rear extensions
- Permitted development rear extensions
- Larger home extension prior approval (England)
- Building Regulations for rear extensions
Rear extension prices in Southend-on-Sea
East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Example | Guide inc VAT |
|---|---|
| Single-storey, 3 m × 4 m (12 m²) | £24,000–£39,500 |
| Single-storey, 4 m × 6 m (24 m²) | £48,500–£79,000 |
| Two-storey, 3 m × 5 m footprint (30 m²) | £57,000–£86,000 |
| Side return, about 14 m² | £34,000–£56,500 |
| Wraparound, about 25 m² | £58,500–£95,500 |
What are homes in Southend-on-Sea like to extend?
Post-war semis and newer estates are typical of Southend-on-Sea, and many have room for a full-width extension. Shrinkable clay is common in the East of England, so foundations near trees and hedges are designed to NHBC-style depth guidance.
Planning rules for Southend-on-Sea
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it 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.
Every rear extension in England needs Building Regulations approval, whether or not planning is needed. You can use the council's building control service or a registered building control approver, by full plans (checked before work, usually within five weeks) or a building notice, and you get a completion certificate at the end.
Nearby towns
FAQ
Questions people ask
How much is a rear extension in Southend-on-Sea?
A 3 m × 4 m single-storey rear extension is about £24,000–£39,500 including VAT at our East of England guide rates; the written price follows a survey.
Do I need planning permission in Southend-on-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 Southend-on-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.