Flat roof extensions across Hoddesdon
We design and build flat roof extensions for houses in Hoddesdon, with a written price once the survey and design are done and one point of contact throughout.
- Guide price in HoddesdonFrom £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 districtsEN10, EN11

Guide prices for Hoddesdon
Prices below are for Hoddesdon, using the East of England factor of ×1.06. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Hoddesdon: £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 |
For a figure based on your own dimensions, use our guide-price tool.
Planning rules that apply in Hoddesdon
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.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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).
Local to Hoddesdon
Across EN10, EN11, we can visit, measure and advise. Nearby, we also take on projects in Hertford (4 miles), Cheshunt (4 miles), Potters Bar (9 miles), Welwyn Garden City (9 miles).
The East of England mixes market-town terraces, inter-war semis and modern estates. Clay soils are common in parts of the region, which can affect foundation design.
Included in a typical project
- Warm-roof design with insulation above the deck
- Falls and outlets designed to drain properly
- Membrane choice: single-ply, EPDM or GRP
- Lanterns or rooflights with upstands
- Parapets or edge trims and flashings to the house
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.
How the project works
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 produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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.
Common questions in Hoddesdon
How long does a flat roof extension take to build in Hoddesdon?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Do I need building regulations approval in Hoddesdon?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will my neighbours in Hoddesdon 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.
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 Hoddesdon
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.