Mortlake, Greater London
Side return extension in Mortlake
We plan and build side return extensions for homeowners in Mortlake. Infilling the narrow passage beside a Victorian or Edwardian back addition. Start with a free site visit, then a written price once the design is agreed.
Mortlake sits in Greater London, with postcode districts including SW13, SW14 and TW9. Side returns suit the Victorian and Edwardian terraces found across parts of Greater London, where the kitchen sits in a narrow back addition.
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 side return extension cost in Mortlake?
Guide prices for a side return extension in Mortlake start from our London rate of £2,990–£4,940 per square metre, including VAT. 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 |
|---|---|
| 2 m wide × 6 m deep (12 m²) | £36,000–£59,500 |
| 2.5 m wide × 7 m deep (17.5 m²) | £52,500–£86,500 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a side return extension in Mortlake?
Planning for a side return extension in Mortlake follows the English householder rules.
Side return infills and the side leg of a wraparound are treated as side extensions in England: single-storey, no more than 4 metres high and no wider than half the original house. They are not permitted development in conservation areas, National Parks or National Landscapes, and a joined wraparound often needs a planning application because the side and rear rules apply together.
The Party Wall etc. Act 1996 applies in England: you serve notice two months before work to a shared wall, and one month before digging foundations within 3 metres (or 6 metres for deeper foundations) of a neighbour's building. Neighbours can agree in writing; if they dissent, surveyors agree an award.
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 Mortlake like to extend?
Much of Mortlake is Victorian and Edwardian terraced housing with narrow back additions, which suits side returns, wraparounds and 3 metre rear extensions. Many streets are in conservation areas, gardens are short, and almost everything comes through the house or along a rear alley.
How a side return extension in Mortlake comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Approvals
Permitted development check, prior approval or planning application, then Building Regulations drawings and structural calculations, plus party wall notices where they apply.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Side return extensions near Mortlake
Neighbouring places we cover include East Sheen (0.5 miles) and Barnes (0.9 miles).
- Side return extension in East Sheen
- Side return extension in Barnes
- Side return extension in Kew
- Side return extension in Roehampton
- Side return extension in Chiswick
Other work in Mortlake:
FAQ
Side return extension questions in Mortlake
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.
Is the site visit in Mortlake free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
How much space does a side return add?
Typically 8 to 18 square metres, enough to turn a galley kitchen into a kitchen-diner with an island.
What postcode areas do you cover around Mortlake?
Including SW13, SW14 and TW9, and the surrounding Greater London area.
Can I live at home while the extension is built?
Usually yes. Most of the work is outside until the back wall is opened near the end, and that stage is screened off.
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.