Flat roof extensions for homes in Bletchley
A flat roof extension in Bletchley 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 BletchleyFrom £23,500 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsMK1, MK2, MK3, MK4, MK6
How much does a flat roof extension cost in Bletchley?
Prices below are for Bletchley, 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 Bletchley: £1,960 to £3,750 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £23,500 – £28,000 | £27,500 – £35,000 | £34,500 – £45,500 |
| 4 m × 5 m 20 m² | £39,000 – £46,000 | £45,500 – £58,500 | £58,000 – £75,500 |
| 5 m × 6 m 30 m² | £58,500 – £69,000 | £68,500 – £87,500 | £87,000 – £113,000 |
For a figure based on your own dimensions, use our guide-price tool.
Planning and approvals in Bletchley
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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.
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).
Covering Bletchley
Postcode districts we cover around Bletchley include MK1, MK2, MK3, MK4, MK6, MK17. We also work in nearby Milton Keynes (3 miles), Aylesbury (13 miles), Chesham (21 miles), Amersham (23 miles).
For homes towards Bedfordshire, Leighton Buzzard is around 6 miles away. 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 we take care of
- Warm-roof design with insulation above the deck
- Falls and outlets designed to drain properly
- Membrane choice: single-ply, EPDM or GRP
- Parapets or edge trims and flashings to the house
- Lanterns or rooflights with upstands
Height is often what decides a flat roof. Under first-floor windows, a pitched roof may not fit at all; a flat roof keeps the extension low while still giving a good ceiling height inside.
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
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
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Bletchley
Do I need building regulations approval in Bletchley?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Do you cover all of Bletchley?
Yes. We cover Bletchley and the surrounding parts of Buckinghamshire. Site visits are free and there is no obligation.
Who do I contract with for a flat roof extension in Bletchley?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Are flat roof extensions cheaper?
Usually slightly, because there is less roof structure and no tiles. Our guide range is about £1,960 to £3,750 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 Bletchley
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.