Flat roof extensions in Bushey: design, approvals and build
Planning a flat roof extension in Bushey? 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 BusheyFrom £22,000 inc VAT
- PlanningOften permitted development (3–4 m), or prior approval up to 6–8 m
- Build time10–16 weeks on site
- Postcode districtsWD1, WD2, WD17, WD18, WD19
Guide prices for Bushey
These guide figures apply our East of England adjustment (×1.06) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Bushey: £1,860 to £3,550 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £22,000 – £26,500 | £26,000 – £33,500 | £33,000 – £43,000 |
| 4 m × 5 m 20 m² | £37,000 – £43,500 | £43,000 – £55,500 | £55,000 – £71,500 |
| 5 m × 6 m 30 m² | £55,500 – £65,500 | £65,000 – £83,000 | £82,500 – £107,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
Covering Bushey
We cover Bushey and the postcode districts WD1, WD2, WD17, WD18, WD19, WD23. The same team covers Watford (2 miles), Borehamwood (4 miles), Rickmansworth (5 miles), St Albans (7 miles), all within easy reach.
Just over the Greater London border, Wealdstone is about 3 miles away. Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
Planning rules that apply in Bushey
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.
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).
When a flat roof extension makes sense
- Modern and 1930s onwards houses
- Extensions under first-floor windows where a pitch will not fit
- Homeowners who want maximum light from above
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
We visit your Bushey home, measure up, talk through what you want and check the planning position.
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
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Flat roof extension questions answered
Do you cover all of Bushey?
Yes. We cover Bushey and the surrounding parts of Hertfordshire. Site visits are free and there is no obligation.
Do I need building regulations approval in Bushey?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
How long does a flat roof extension take to build in Bushey?
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 £1,860 to £3,550 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 Bushey
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.