Hillingdon, Greater London
Single-storey rear extension in Hillingdon
We plan and build single-storey rear extensions for homeowners in Hillingdon. Ground-floor space across the back of the house, usually for a kitchen, dining or family room. Start with a free site visit, then a written price once the design is agreed.
Hillingdon sits in Greater London, with postcode districts including UB3, UB4, UB7 and UB8. A single-storey rear extension in Hillingdon is mostly built from the garden side, so the house stays usable for most of the job.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a single-storey rear extension cost in Hillingdon?
A single-storey rear extension in Hillingdon is priced at £2,470–£4,030 per square metre including VAT as a guide, before kitchen fit-out and fees. London prices sit at the top of our range because of labour rates, access through the house, parking suspensions and skip licences.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £29,500–£48,500 |
| 4 m wide × 5 m deep (20 m²) | £49,500–£80,500 |
| 4 m wide × 6 m deep (24 m²) | £59,500–£96,500 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a single-storey rear extension in Hillingdon?
Whether your single-storey rear extension in Hillingdon needs a planning application depends on its size, your house and any local restrictions.
Under England's householder permitted development rules you can usually add 3 metres at the back of an attached house, or 4 metres on a detached house, without a planning application, as long as the extension stays under 4 metres high and its eaves stay under 3 metres where it is within 2 metres of a boundary.
If 3 or 4 metres is not enough, England's prior approval route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for a single-storey rear extension. Neighbours are consulted, the council decides within 42 days, and the fee is £249, rising to £310 from 8 December 2026.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Hillingdon like to extend?
Hillingdon is mostly 1930s semis, short terraces and post-war houses, so full-width single-storey and two-storey rear extensions are realistic on many plots. Some later estates had permitted development rights removed by condition, so we check the planning history first.
How a single-storey rear extension in Hillingdon comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Drawings and budget
Floor plans and elevations for the options, each with a guide price.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Single-storey rear extensions near Hillingdon
We also build single-storey rear extensions in nearby Uxbridge (1.7 miles) and Hayes (1.7 miles).
- Single-storey rear extension in Uxbridge
- Single-storey rear extension in Hayes
- Single-storey rear extension in Ickenham
- Single-storey rear extension in West Drayton
- Single-storey rear extension in South Ruislip
Other work in Hillingdon:
FAQ
Single-storey rear extension questions in Hillingdon
Do you handle building control in Hillingdon?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
How long does a rear extension take to build in Hillingdon?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Do I need a structural engineer?
Yes for the beam over the new opening and usually for the foundations. Their calculations go to building control with the drawings.
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
What postcode areas do you cover around Hillingdon?
Including UB3, UB4, UB7, UB8, UB10 and UB11, and the surrounding Greater London area.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.