Covering Brentwood
Our coverage around Brentwood (CM14) also includes Billericay, Hornchurch and Romford.
Homes in the East of England
Across the East of England, newer estates often have integral garages and room for rear extensions, while older towns have Victorian terraces and conservation areas that shape what can be built.
What is a side return extension?
Side returns are small in area but heavy in detail: party walls, a glazed roof, and steelwork to take out the original back wall. We design the roof for light and drainage, agree the party wall process early, and keep the work tidy because access is often through the house.
- Structural steel to remove the side wall
- Glazed or solid roof with rooflights
- Underfloor heating ready screed if wanted
How much does a side return extension cost in Brentwood?
What side return extensions typically cost. These are guide ranges; the written quote for your house replaces them.
| Side return extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £3,350 to £3,700 per m² |
| Good specification | £3,700 to £4,150 per m² |
| High specification | £4,150 to £4,550 per m² |
What approvals does a side return extension need in England?
In England we deal with the council’s planning team for permission or a lawful development certificate, with building control (the council or a registered building control approver) for inspections, and with neighbours under the Party Wall etc. Act 1996 where it applies.
In England a single-storey rear extension can often go ahead under permitted development: up to 3 m deep on an attached house or 4 m on a detached one, no higher than 4 m, with eaves no higher than 3 m within 2 m of a boundary.
What can affect a side return extension?
- Glazed roofs need careful detailing against the neighbour’s wall.
- Many terraces sit in conservation areas, where side extensions need planning permission.
From first call to completion
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
What people ask before starting
How much does a side return extension cost?
Usually about £3,350 to £4,550 per square metre including VAT, which works out at around £35,000 to £55,000 for a typical side return before the kitchen.
Does a side return need planning permission?
In England it can be permitted development if it is single storey, no higher than 4 m and no wider than half the original house. Conservation areas are the main exception.
Do you work in Brentwood?
Yes. Brentwood is within our coverage for side return extensions, along with nearby Billericay and Hornchurch.
Other towns nearby
- Side return extensions in Billericay
- Side return extensions in Hornchurch
- Side return extensions in Romford
- Side return extensions in Basildon
Learn more about side return extensions, or see every project we cover in Brentwood.

