Harrow, Greater London
Kitchen-diner rear extension in Harrow
We plan and build kitchen-diner rear extensions for homeowners in Harrow. An open-plan kitchen, dining and family room that opens straight onto the garden. Start with a free site visit, then a written price once the design is agreed.
Harrow sits in Greater London, with postcode districts including HA1, HA2, HA3 and HA5. We usually keep the working kitchen where the old one was and put the dining table in the new space by the doors, which suits most Harrow homes.
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 kitchen-diner rear extension cost in Harrow?
In Harrow, our guide for a kitchen-diner rear extension is £2,470–£4,030 per square metre including VAT for a standard specification. 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 kitchen-diner rear extension in Harrow?
Whether your kitchen-diner rear extension in Harrow needs a planning application depends on its size, your house and any local restrictions.
English permitted development (Class A) allows a single-storey rear extension of 3 metres on a terraced or semi-detached house and 4 metres on a detached one, measured from the original house, with a maximum height of 4 metres and eaves of no more than 3 metres within 2 metres of a boundary.
England also has the larger home extension route: a single-storey rear extension of up to 6 metres on an attached house or 8 metres on a detached house, after prior approval from the council. The council notifies your neighbours and has 42 days to decide; the fee is £249 (£310 for applications made from 8 December 2026). The route is not available on designated land such as conservation areas.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. At the first visit we measure what is there now and tell you which route fits: permitted development, prior approval or a planning application.
What are homes in Harrow like to extend?
Much of Harrow is 1920s and 1930s semis and short terraces with longer gardens than inner London, which suit full-width single-storey rear extensions. Parking suspensions, skip licences and controlled hours on residential streets shape the programme more than the build itself.
How a kitchen-diner rear extension in Harrow 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.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
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.
Kitchen-diner rear extensions near Harrow
Close by, we work in Harrow on the Hill, about 0.5 miles away, and Headstone, about 1.1 miles away.
- Kitchen-diner rear extension in Harrow on the Hill
- Kitchen-diner rear extension in Headstone
- Kitchen-diner rear extension in Wealdstone
- Kitchen-diner rear extension in Sudbury
- Kitchen-diner rear extension in Harrow Weald
Other work in Harrow:
FAQ
Kitchen-diner rear extension questions in Harrow
Is the site visit in Harrow free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
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.
How big should a kitchen-diner be?
Around 25 to 35 m² for the combined kitchen, dining and seating areas suits most family homes. Your survey shows what fits the house.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
Do you handle building control in Harrow?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
What postcode areas do you cover around Harrow?
Including HA1, HA2, HA3, HA5 and HA7, and the surrounding Greater London area.