Flat roof extensions for homes in Swindon
A flat roof extension in Swindon starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide price in SwindonFrom £21,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsSN1, SN2, SN3, SN4, SN5
What we take care of
- Lanterns or rooflights with upstands
- Membrane choice: single-ply, EPDM or GRP
- Warm-roof design with insulation above the deck
- Falls and outlets designed to drain properly
Working in Swindon
We cover Swindon and the postcode districts SN1, SN2, SN3, SN4, SN5, SN25. Neighbouring towns we cover include Calne (12 miles), Chippenham (16 miles), Devizes (18 miles), Melksham (20 miles).
Just over the Gloucestershire border, Cirencester is about 14 miles away. South West homes range from terraced streets in the cities to stone cottages and bungalows in the countryside, and conservation areas are common in historic centres.
Do I need planning permission in Swindon?
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.
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.
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).
Flat roof extension prices in Swindon
Prices below are for Swindon, using the South West England factor of ×1.02. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Swindon: £1,780 to £3,420 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £21,000 – £25,500 | £25,000 – £32,000 | £31,500 – £41,500 |
| 4 m × 5 m 20 m² | £35,500 – £42,000 | £41,500 – £53,500 | £53,000 – £68,500 |
| 5 m × 6 m 30 m² | £53,500 – £63,000 | £62,500 – £80,000 | £79,500 – £103,000 |
For a figure based on your own dimensions, use our guide-price tool.
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions people ask about flat roof extensions
Will my neighbours in Swindon 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 you cover all of Swindon?
Yes. We cover Swindon and the surrounding parts of Wiltshire. Site visits are free and there is no obligation.
How long does a flat roof extension take to build in Swindon?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Are flat roof extensions cheaper?
Usually slightly, because there is less roof structure and no tiles. Our guide range is about £1,780 to £3,420 per m² including VAT.
Can I walk on a flat roof extension?
Only for maintenance unless it is designed as a terrace. A roof terrace or balcony needs planning permission and a different structure.
Book a free site visit in Swindon
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.