Pitched roof extensions for homes in Windsor
Thinking about a pitched roof extension for your Windsor home? Start with a free site visit: we measure up, check what the council will allow and give you honest guide figures on the day.
- Guide price in WindsorFrom £24,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsSL1, SL3, SL4
What is included
- Vaulted ceilings or flat ceilings with storage above
- Roof windows positioned for light and ventilation
- Roof design matched to the existing pitch and tiles
- Lead or proprietary flashings to the main wall
- Insulation to current building regulations
Pitched roof extension prices in Windsor
Prices below are for Windsor, using the South East England factor of ×1.12. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Windsor: £2,070 to £3,920 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £24,500 – £29,000 | £28,500 – £37,000 | £36,500 – £47,500 |
| 4 m × 5 m 20 m² | £41,000 – £48,500 | £48,000 – £62,000 | £61,500 – £78,500 |
| 5 m × 6 m 30 m² | £62,000 – £72,500 | £72,000 – £92,500 | £92,000 – £118,000 |
For a figure based on your own dimensions, use our guide-price tool.
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 regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Local to Windsor
Postcode districts we cover around Windsor include SL1, SL3, SL4. Neighbouring towns we cover include Slough (2 miles), Maidenhead (6 miles), Bracknell (8 miles), Wokingham (11 miles).
Just over the Surrey border, Egham is about 4 miles away. 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.
What happens next
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 Windsor 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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions people ask about pitched roof extensions
How long does a pitched roof extension take to build in Windsor?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 6–12 weeks design and approvals.
Do I need building regulations approval in Windsor?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will my neighbours in Windsor 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.
Is a pitched roof better than a flat roof?
Neither is better in all cases. Pitched roofs blend with traditional houses and shed water quickly; flat roofs give more headroom and suit modern designs and lanterns.
How much does a pitched roof extension cost?
Our guide range is about £2,070 to £3,920 per m² including VAT, a little more than a flat roof because of the roof structure and tiles.
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.