Side return extensions in Berkshire
Planning a side return extension in Berkshire? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide priceFrom £20,000 inc VAT
- PlanningOften permitted development; party wall notice usual
- Towns covered11
- Site visitFree, no obligation

Towns in Berkshire
Working in Berkshire
Towns we cover in Berkshire include Reading, Slough, Bracknell, Maidenhead, Wokingham, Newbury, Earley, Windsor. In the South East, plenty of houses have already been extended once, which makes checking the remaining permitted development allowance an important early step.
What should I budget for a side return extension in Berkshire?
For Berkshire we adjust our national guide rates by ×1.12, the factor we use for South East England. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Berkshire: £2,350 to £4,260 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 1.8 m × 4.5 m 8 m² | £20,000 – £24,000 | £21,500 – £27,000 | £26,500 – £34,500 |
| 2 m × 5.5 m 11 m² | £25,500 – £31,000 | £29,500 – £37,000 | £36,500 – £47,000 |
| 2.2 m × 7 m 15 m² | £35,000 – £42,500 | £40,000 – £50,500 | £50,000 – £64,000 |
For a figure based on your own dimensions, use our guide-price tool.
Included in a typical project
- Survey of the outrigger, boundary wall and drainage
- Kitchen-ready shell or full finish
- Party wall notice support (England and Wales)
- Design to keep daylight in the middle of the house
- New boundary wall or raised party wall
Do I need planning permission in Berkshire?
In England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.
Applications are decided by the local planning authority (your district, borough or unitary council).
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Berkshire home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Your questions about a side return extension in Berkshire
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Berkshire, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does a side return extension take to build in Berkshire?
On site, typically 10 to 14 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
Will my neighbours in Berkshire be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
Do side return extensions need planning permission?
In England many single-storey side returns fit within permitted development if they stay within the height limits and are no wider than half the width of the original house. Conservation areas, listed buildings and flats need an application. Other UK nations have their own rules, which we check.
How much does a side return extension cost?
Our guide range is about £2,350 to £4,260 per m² including VAT, so a typical 2 m × 5.5 m infill lands around £29,500 to £37,000 at standard spec in Berkshire, more in London.
Book a free site visit in Berkshire
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.