Covering Sunbury-on-Thames
Our coverage around Sunbury-on-Thames (TW16, TW17) also includes Walton-on-Thames, Hanworth and Ashford.
Homes in the South East
Many South East homes are inter-war or post-war semis and detached houses with room for rear and side extensions, while historic town centres and villages bring conservation area and listed building controls.
What is a single-storey extension?
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
- Foundations, drainage and structural steel
- First-fix and second-fix electrics, plastering and making good
What is the guide price for a single-storey extension in Sunbury-on-Thames?
What single-storey extensions typically cost. These are guide ranges; the written quote for your house replaces them.
| 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 |
How is a single-storey extension approved in Sunbury-on-Thames?
English projects need planning clearance from the local council, building regulations sign-off from building control, and party wall notices where the work is on or near a shared boundary. We prepare and manage all three.
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.
- Building on or near a shared boundary usually means serving a party wall notice in England and Wales.
From first call to completion
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- 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.
Your questions answered
How much does a single-storey extension cost?
Most single-storey extensions cost about £2,600 to £4,000 per square metre including VAT, depending on specification, glazing and ground conditions. We give a fixed price in writing for the agreed specification after the survey.
Will the brick match?
We source the closest available match for colour, size and texture and agree a sample panel with you before laying.
Can you visit a house in Sunbury-on-Thames 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
- Single-storey extensions in Walton-on-Thames
- Single-storey extensions in Hanworth
- Single-storey extensions in Ashford
- Single-storey extensions in Feltham
Learn more about single-storey extensions, or see every project we cover in Sunbury-on-Thames.

