Side extensions in Borehamwood: design, approvals and build
Planning a side extension in Borehamwood? 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 BorehamwoodFrom £23,000 inc VAT
- PlanningSingle storey can be permitted development
- Build time10–18 weeks on site
- Postcode districtsWD6, WD7
Who a side extension suits
- Houses where the rear garden is small
- Homes needing a utility, study or ground-floor bedroom
- Detached and semi-detached houses with side land
Working in Borehamwood
Across WD6, WD7, we can visit, measure and advise. We also work in nearby Bushey (4 miles), Potters Bar (5 miles), Watford (5 miles), St Albans (7 miles).
For homes towards Greater London, Barnet is around 3 miles away. 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.
Side extension prices in Borehamwood
Prices below are for Borehamwood, 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 Borehamwood: £1,860 to £3,600 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £23,000 – £28,000 | £26,000 – £34,000 | £33,000 – £43,500 |
| 3 m × 6 m 18 m² | £33,000 – £40,500 | £39,000 – £51,000 | £49,500 – £65,000 |
| 3 m × 8 m 24 m² | £44,500 – £53,500 | £52,000 – £67,500 | £66,000 – £86,500 |
Want a range for your exact size? The guide-price tool takes about a minute.
Will the council need to approve it?
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
The planning position for a specific Borehamwood address depends on its history and any designations, which is why we check it at the first visit.
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).
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
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Side extension questions answered
Who do I contract with for a side extension in Borehamwood?
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.
Will my neighbours in Borehamwood 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.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Borehamwood, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How close to the boundary can I build?
It depends on height. In England, within 2 m of a boundary the eaves must not exceed 3 m under permitted development. Building on the boundary is possible but brings party wall and maintenance access issues we plan for.
Can I build over my driveway?
Yes, if the foundations work and you keep any parking the council requires. Drains and services under drives are common, so we check before design.
Book a free site visit in Borehamwood
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.