Covering Chelmsford
Our coverage around Chelmsford (CM1, CM99) also includes Billericay, Witham and Maldon.
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 goes into 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.
- Glazed or solid roof with rooflights
- Underfloor heating ready screed if wanted
- Plastering and making good to the old house
What is the guide price for a side return extension in Chelmsford?
Indicative costs for side return extensions. London and the South East usually sit towards the top of each range.
| 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 |
Do you need permission for a side return extension in Chelmsford?
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. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.
What should I think about before starting?
- Most side returns touch a shared boundary, so the Party Wall etc. Act 1996 usually applies in England and Wales.
- Glazed roofs need careful detailing against the neighbour’s wall.
How does the project run?
- Send us the details. Give us a postcode, a rough idea of size and some photos, by phone, form or the guide price tool.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Price and paperwork. The design is priced line by line, and we submit the planning and building control applications.
- We build it. Work follows an agreed programme, with inspections at each stage and a final sign-off.
Questions about a side return extension in Chelmsford
Is a glazed roof too hot in summer?
Modern solar-control glass and a mix of glazed and solid roof keep it comfortable. We advise on the balance during design.
How long does a side return take?
About 10 to 14 weeks on site.
Can you visit a house in Chelmsford to quote?
Yes. After a short call we arrange a site visit to measure up and agree what the design needs to do, then send a written price.
Also covering
- Side return extensions in Billericay
- Side return extensions in Witham
- Side return extensions in Maldon
- Side return extensions in Wickford
Learn more about side return extensions, or see every project we cover in Chelmsford.

