Brentwood, Essex
Side return extension in Brentwood
Infilling the narrow passage beside a Victorian or Edwardian back addition. We design, get the approvals for and build side return extensions in Brentwood and the surrounding area, with one contract from the first survey to building control sign-off.
Brentwood sits in Essex, with postcode districts including CM13, CM14 and CM15. Side returns suit the Victorian and Edwardian terraces found across parts of Essex, where the kitchen sits in a narrow back addition.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a side return extension cost in Brentwood?
In Brentwood, our guide for a side return extension is £2,440–£4,030 per square metre including VAT for a standard specification. East of England prices run slightly above our West Midlands baseline; clay soils near trees are the main foundation variable.
| Size | Guide price inc VAT |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £29,500–£48,500 |
| 2.5 m wide × 7 m deep (17.5 m²) | £42,500–£70,500 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a side return extension in Brentwood?
Here is how the rules in England apply to a side return extension in Brentwood.
Side return infills and the side leg of a wraparound are treated as side extensions in England: single-storey, no more than 4 metres high and no wider than half the original house. They are not permitted development in conservation areas, National Parks or National Landscapes, and a joined wraparound often needs a planning application because the side and rear rules apply together.
The Party Wall etc. Act 1996 applies in England: you serve notice two months before work to a shared wall, and one month before digging foundations within 3 metres (or 6 metres for deeper foundations) of a neighbour's building. Neighbours can agree in writing; if they dissent, surveyors agree an award.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Brentwood like to extend?
Post-war semis and newer estates are typical of Brentwood, 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.
How a side return extension in Brentwood comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Side return extensions near Brentwood
Neighbouring places we cover include Harold Wood (3.6 miles) and Emerson Park (4.5 miles).
- Side return extension in Harold Wood
- Side return extension in Emerson Park
- Side return extension in Billericay
- Side return extension in Upminster
- Side return extension in Hornchurch
Other work in Brentwood:
FAQ
Side return extension questions in Brentwood
What postcode areas do you cover around Brentwood?
Including CM13, CM14 and CM15, and the surrounding Essex area.
Do I need planning permission for a rear extension in Brentwood?
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.
Glass roof or solid roof with rooflights?
A glass roof gives the most light; a solid roof with long rooflights is warmer and quieter in rain. Both work.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
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.