Side return extensions in Windsor

Covering Windsor

Windsor is about 16 miles east of Reading. We also cover Slough (2 miles to the north), Egham and Staines.

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 does a side return extension involve?

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
Underfloor heating ready screed if wanted
Plastering and making good to the old house

How much should I budget for a side return extension?

Typical ranges for side return extensions. Ground conditions, access and specification move the final figure, which we fix in writing before work starts.

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. Deeper extensions, up to 6 m or 8 m, need prior approval from the council first.

What can affect a side return extension?

Most side returns touch a shared boundary, so the Party Wall etc. Act 1996 usually applies in England and Wales.
Access is often through the house, so we plan deliveries and protect floors.

What happens after I enquire?

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.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Questions about a side return extension in Windsor

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.

Does a side return need planning permission?

In England it can be permitted development if it is single storey, no higher than 4 m and no wider than half the original house. Conservation areas are the main exception.

How do I get a price for side return extensions in Windsor?

Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.

Also covering

Learn more about side return extensions, or see every project we cover in Windsor.