Covering Sunbury-on-Thames
Sunbury-on-Thames sits 13 miles north-east of Guildford, with Walton-on-Thames 1 miles to the south and Hanworth 3 miles to the north-east.
Homes in the South East
The South East has a lot of 1930s and post-war semi-detached housing, well suited to rear extensions and hip-to-gable loft conversions, alongside period properties in conservation areas that need a more careful design.
What do you get with 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.
- Structural steel to remove the side wall
- Drainage and new gully positions
- Plastering and making good to the old house
What will a side return extension cost?
What side return extensions typically cost. These are guide ranges; the written quote for your house replaces them.
| 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 |
What approvals does a side return 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 should Sunbury-on-Thames homeowners check first?
- 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.
What happens after I enquire?
- Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
- Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
- Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
- Construction and completion. One site lead co-ordinates every trade through to the building control certificate.
What people ask before starting
How much does a side return extension cost?
Usually about £3,350 to £4,550 per square metre including VAT, which works out at around £35,000 to £55,000 for a typical side return before the kitchen.
How long does a side return take?
About 10 to 14 weeks on site.
Who deals with the council for a project in Sunbury-on-Thames?
We do. We prepare the drawings, submit planning or permitted development paperwork if needed, and arrange building control inspections.
Side return extensions near Sunbury-on-Thames
- Side return extensions in Walton-on-Thames
- Side return extensions in Hanworth
- Side return extensions in Ashford
- Side return extensions in Feltham
Learn more about side return extensions, or see every project we cover in Sunbury-on-Thames.

