Colchester, Essex
Single-storey rear extension in Colchester
Thinking about a single-storey rear extension in Colchester? Ground-floor space across the back of the house, usually for a kitchen, dining or family room. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
We cover Colchester (CO1, CO2, CO3 and CO4) as part of our Essex work. A depth of 3 to 4 metres keeps many single-storey rear extensions in Colchester within permitted development, subject to the house's planning history.
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 single-storey rear extension cost in Colchester?
Guide prices for a single-storey rear extension in Colchester start from our East of England rate of £2,010–£3,290 per square metre, including VAT. 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 |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £24,000–£39,500 |
| 4 m wide × 5 m deep (20 m²) | £40,500–£65,500 |
| 4 m wide × 6 m deep (24 m²) | £48,500–£79,000 |
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 single-storey rear extension in Colchester?
Whether your single-storey rear extension in Colchester needs a planning application depends on its size, your house and any local restrictions.
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.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
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 Colchester like to extend?
Colchester mixes Victorian terraces with 1930s semis, so both side returns and full-width kitchen extensions suit houses here.
How a single-storey rear extension in Colchester 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.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Fixed price and build
A written price for the agreed design, a start date and a named contact through the build, ending with the building control completion certificate.
Single-storey rear extensions near Colchester
We also build single-storey rear extensions in nearby Halstead (11.9 miles) and Sudbury (12.7 miles).
- Single-storey rear extension in Halstead
- Single-storey rear extension in Sudbury
- Single-storey rear extension in Clacton-on-Sea
- Single-storey rear extension in Witham
- Single-storey rear extension in Maldon
Other work in Colchester:
FAQ
Single-storey rear extension questions in Colchester
How much does a single-storey rear extension cost in Colchester?
As a guide, £2,010–£3,290 per square metre including VAT for a standard specification. For example, 3 m wide × 4 m deep (12 m²): about £24,000–£39,500 at that rate. Your written price follows the survey.
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.
Is a flat roof or a pitched roof better?
A warm flat roof keeps the extension low under first-floor windows and suits a roof lantern; a pitched or lean-to roof gives a vaulted ceiling. Both last for decades when built properly.
Do I need planning permission for a rear extension in Colchester?
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 Colchester free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
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.