Rickmansworth single-storey extensions, designed and built
A single-storey extension in Rickmansworth 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 RickmansworthFrom £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 districtsWD3
Planning rules that apply in Rickmansworth
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.
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 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).
Included in a typical project
- Doors, windows, insulation, plastering and first fix to finish
- Building regulations drawings and structural calculations
- Walls, steel beams and the new opening into the house
- Foundations, drainage and groundworks
Working in Rickmansworth
Postcode districts we cover around Rickmansworth include WD3. The same team covers Watford (4 miles), Bushey (5 miles), Hemel Hempstead (8 miles), Borehamwood (9 miles), all within easy reach.
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.
Single-storey extension prices in Rickmansworth
Prices below are for Rickmansworth, 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 Rickmansworth: £1,860 to £3,600 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 – £43,500 |
| 4 m × 5 m 20 m² | £37,000 – £43,500 | £43,000 – £55,500 | £55,000 – £72,500 |
| 5 m × 6 m 30 m² | £55,500 – £65,500 | £65,000 – £83,000 | £82,500 – £108,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
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 Rickmansworth 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
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Single-storey extension questions answered
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Rickmansworth, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Who do I contract with for a single-storey extension in Rickmansworth?
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.
How long does a single-storey extension take to build in Rickmansworth?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Can I stay in the house during the build?
Usually yes. Most of the work happens outside until the final weeks, when we open the rear wall. We plan that stage carefully and seal the opening with a temporary screen to keep dust down.
Flat roof or pitched roof?
Flat roofs give more headroom inside and suit lanterns and rooflights; pitched roofs can blend better with older houses. Both meet building regulations when built properly. See our flat roof and pitched roof pages for the details.
Book a free site visit in Rickmansworth
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.