Side Return Extensions
Side Return Extensions
Transform that unused alleyway into valuable living space. Side return extensions are one of the most cost effective ways to add space to Victorian and Edwardian homes.
- Typically adds 5 to 8 m² of valuable floor space
- Often combined with rear extension for larger kitchen diners
- Most qualify for Permitted Development
- Can accommodate new kitchen, utility room, or WC
- Minimal garden space lost
Industry average
£36,000 – £48,000
Our starting price
£30,000
Typical side return around 12 to 15 m². Strong supplier relationships and efficient sequencing keep costs below market rates.
Why we're more affordable
- Internal supply chains — we source materials at trade prices
- Optimised systems — efficient planning reduces wasted time and materials
- Strong project management — we complete on time, keeping costs under control
Fixed price quote within 5 working days
Verified client reviews and 350+ completed projects
About this service
About side return extensions
A side return extension fills in the narrow alleyway running alongside your property (the "side return") to create additional ground floor space. This is extremely common on Victorian and Edwardian terraced houses in London, where the original layout often includes this unused strip. Side returns typically add 5 to 8 m² of valuable floor space and start from £30,000 for a straightforward build.
Who it's for
Owners of Victorian or Edwardian terraced properties with an unused side return alleyway. This is one of the most popular extension types in London because it creates significant space without sacrificing garden area.
GOV.UK: Party Wall Act GuideScope
What's Included
- Site survey and measured drawings
- Construction from your approved plans
- Building Regulations submission and inspections
- Complete construction including drainage alterations
- Optional: Structural design and RSJ calculations (quoted separately)
- Optional: Party Wall Agreement assistance (quoted separately)
Process
How it Works
Survey & Plan Review
We review your property and architectural plans to design the extension build approach.
Optional Services
We can arrange Party Wall notices and submit Building Regulations applications if required.
Build & Completion
Excavation, foundations, drainage, brickwork, steel installation, roofing, and full interior fit out.
Our work
Related completed work
Reviews
What homeowners say
What homeowners say about working with us on house extensions.
“Shahbaz and his labour team did my side and rear extension in addition to refurbishment of my rental property and overall I was pleased with the results of both properties. I can't say the same for his two partners but he was very considerate, true to his words and always available to address our concerns even if he was pressured by his partners to otherwise. In addition, Shabhaz always recommended best quality material and product for construction and suppliers. Overall, I would highly recommend Shahbaz and his labour team from Brits Construction to lead to deliver a good quality project.”
arana198
6m kitchen and side extension · Harrow ·
Review on MyBuilder
“Brits took on a full house gut and extension. The project overan by 2 months but during the time of Covid etc it wasnt entirely their fault. I will 100% recommend these guys who were always honest, kept to the job at hand and was managed excellently. The PM was on site 2-3 times daily and was always at hand to discuss. With all jobs of this nature there are problems but I hoenstly can confirm that they were very professional with debates and discussions, and never got emotional or upset. Fahim the PM really does have a good heart and best intentions. My job was completed 99% to my satisfaction and at the beginning, i didnt think i would be this happy. Even 6 months of moving in there have been a few issues (odd leak, paintwork or heating issues) they have come back to rectify and redo the work. There is still few V. minor items and they have said to let settlement cracks settle for a year and they will come to redo this. (its not been done yet but i do trust and believe that they will based on all other things post completion). There has not been a single person whos been to the house who has not been wowed by the work and most importantly finishing. I will recommend and use again in future based on this experience.”
mayurmohanlal
Double side and rear extension. Plus renovation · Ruislip ·
Review on MyBuilder
“Brits Construction has completed a great job. Syed and his team were dedicated and very professional in meeting our expectations for a rather complex project located in a conservation area. Syed, the manager, was extremely and constantly available from the beginning to the end of the works (extension and ground floor improvement). We could rely on him and his team with full confidence. I highly recommend Brits Construction to anyone seeking peace of mind and an efficient, professional builder always ready to find solutions.”
Emmanuel Serghini-barre
Review on Google
FAQ
Common Questions
A side return extension fills in the narrow alleyway (typically 1 to 1.5m wide) that runs alongside Victorian and Edwardian houses. This "side return" was originally left to provide light to downstairs rooms. Filling it in creates valuable extra space for kitchens, dining areas, or utility rooms.
If your extension touches or affects the party wall (the shared wall between properties), you will need to serve a Party Wall Notice. We handle this process for you, including appointing surveyors if your neighbour dissents.
Yes, and this is very common. A combined side return and rear extension creates a large L shaped kitchen diner, one of the most sought after layouts in London. The combined project often costs less per m² than doing them separately.
Most side returns have existing drainage runs that need to be diverted. We include all necessary drainage alterations in our quotes and coordinate with Thames Water or the relevant authority for build-over agreements.
Where we build side return extensions
Our team is based in Harrow and works across London and the Home Counties, including:
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Ready to start your project?
Fixed price quote within 5 working days. No obligation.