Covering Becontree
Alongside Becontree, we also cover Dagenham, Barking (2 miles to the south-west) and Ilford.
Homes in London
Much of London’s housing is Victorian and Edwardian terraces, which is why side return extensions, rear dormers and mansards are so common. Many streets are in conservation areas, and several boroughs use Article 4 directions that remove some permitted development rights.
What does a single-storey extension involve?
We design the extension around how you use the house: where the light comes from, how the new room joins the old one, and what happens to the drains and the garden. The structure is built in brick or block to match the house, finished with a flat roof and lantern or a pitched roof, then insulated, plastered and handed back ready to decorate.
- Measured survey and design drawings
- Building control application and inspections
- Foundations, drainage and structural steel
What will a single-storey extension cost?
Use these ranges to budget for single-storey extensions; the survey turns them into a fixed price for the agreed specification.
| Single-storey extensions | Guide price incl. VAT |
|---|---|
| Standard specification | £2,600 to £3,000 per m² |
| Good specification | £3,000 to £3,500 per m² |
| High specification | £3,500 to £4,000 per m² |
What approvals does a single-storey 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 single-storey extension?
- Drains under the footprint may need diverting or a build-over agreement with the water company.
- Large glazed areas need to meet energy rules, which can shape the size of doors and rooflights.
From first call to completion
- Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
- Free site visit. We measure up, look at access, drains and the structure, and talk through options and budget.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.
What people ask before starting
How long does a single-storey extension take to build?
The build itself usually takes 10 to 16 weeks once work starts on site. Design, approvals and ordering usually add 6 to 12 weeks before that.
Do you need to dig up the drains?
Sometimes. If a public sewer runs under the extension, the water company has to agree a build-over or a diversion. We check this at survey stage.
Do you work in Becontree?
Yes. Becontree is within our coverage for single-storey extensions, along with nearby Dagenham and Barking.
Also covering
- Single-storey extensions in Dagenham
- Single-storey extensions in Barking
- Single-storey extensions in Ilford
- Single-storey extensions in Romford
Learn more about single-storey extensions, or see every project we cover in Becontree.

