Utility and boot room extensions in Windsor
Planning a utility room extension in Windsor? 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 price in WindsorFrom £15,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time6–10 weeks on site
- Postcode districtsSL1, SL3, SL4

Planning and approvals in Windsor
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
Utility room extension prices in Windsor
For Windsor 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 Windsor: £2,130 to £3,920 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 2.5 m 5 m² | £15,500 – £19,000 | £15,500 – £20,000 | £15,500 – £20,000 |
| 2.5 m × 3.2 m 8 m² | £17,000 – £20,500 | £20,000 – £25,500 | £25,000 – £31,500 |
| 3 m × 3.6 m 11 m² | £23,000 – £28,000 | £27,500 – £34,500 | £34,000 – £43,500 |
For a figure based on your own dimensions, use our guide-price tool.
Is a utility room extension right for your house?
- Kitchens that have run out of space for appliances
- Houses with a side passage or small rear corner
- Busy family homes
Extensions in and around Windsor
We cover Windsor and the postcode districts SL1, SL3, SL4. We also work in nearby Slough (2 miles), Maidenhead (6 miles), Bracknell (8 miles), Wokingham (11 miles).
Egham, in Surrey, is roughly 4 miles from Windsor and also on our list. The South East has a broad mix of 1930s semis, post-war estates, newer developments and period cottages, and many houses have enough garden for a generous rear extension.
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Your questions about a utility room extension in Windsor
How long does a utility room extension take to build in Windsor?
On site, typically 6 to 10 weeks once approvals are in place. Before that, allow 4–10 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Windsor, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do you cover all of Windsor?
Yes. We cover Windsor and the surrounding parts of Berkshire. Site visits are free and there is no obligation.
How much does a utility room extension cost?
Our guide range is about £2,130 to £3,920 per m² including VAT, with a minimum of around £16,000. An 8 m² standard-spec utility is typically £20,000 to £25,500 in Windsor.
Can a utility have a toilet?
Yes, space permitting. A WC needs drainage and extraction, which we plan into the design.
Book a free site visit in Windsor
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.