Isleworth, Greater London
Side return extension in Isleworth
We plan and build side return extensions for homeowners in Isleworth. 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.
Isleworth sits in Greater London, with postcode districts including TW3, TW5 and TW7. 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 Isleworth?
For Isleworth we work from the London rate: £2,990–£4,940 per square metre of new floor, including VAT, 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 |
|---|---|
| 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 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission for a side return extension in Isleworth?
Planning for a side return extension in Isleworth 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 Isleworth like to extend?
Much of Isleworth 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 side return extension in Isleworth comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
Paperwork handled
Planning, prior approval or permitted development, Building Regulations approval, structural design and party wall notices are all handled by us.
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 Isleworth
Neighbouring places we cover include Osterley (0.6 miles) and Hounslow (0.9 miles).
- Side return extension in Osterley
- Side return extension in Hounslow
- Side return extension in Heston
- Side return extension in Brentford
- Side return extension in Richmond
Other work in Isleworth:
FAQ
Side return extension questions in Isleworth
Do I need planning permission for a rear extension in Isleworth?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Is the site visit in Isleworth free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.
Where does the drainage go?
Side passages often carry the soil and rainwater pipes. We survey them first and reroute them under the new floor where needed.
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.
Do you handle building control in Isleworth?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.