Side Return Extension Specialists in London
That narrow alley down the side of your terrace? We turn it into usable kitchen space.
All Well Property Services provides professional side return extensions across South East London. Prices range from £35,000to £55,000. Typical build time: 8–10 weeks. All projects include a fixed-price contract, single project manager, and full Building Control sign-off. Call 020 3920 9617 for a free consultation.
What We Offer
That narrow alley down the side of your terrace? We turn it into usable kitchen space. Side return extensions add width to your ground floor without touching the garden. Ideal for Victorian and Edwardian terraces across South London.
- ✓Victorian and Edwardian terrace specialists
- ✓Side passage to kitchen-diner conversion
- ✓Structural steelwork and RSJs
- ✓Bifold and sliding door installation
- ✓Underfloor heating
- ✓Full electrical and plumbing fit-out
- ✓Building Control sign-off included
- ✓FENSA registered glazing
Typical Investment
8–10 weeks | Fixed-price contracts
Standard side return infill
Glazed roof, opening up to kitchen
£35,000 – £45,000
Side return with rear extension
Combined side + rear for maximum space
£45,000 – £65,000
Most clients with Victorian terraces typically invest between £38,000 and £50,000 to open up their side return into a bright kitchen-diner.
Fixed-price contracts | No hidden costs | 8–10 week typical build
What Affects the Cost?
- •Length of the side return passage
- •Glazing specification (Crittall-style vs standard)
- •Structural steelwork to open up the wall
- •Kitchen fit-out specification
- •Access and scaffolding requirements
Our side return extension experience
Side return extensions are one of our most-requested projects across London's terraced housing stock. Since 2020 we have built side returns across SW and SE London. Median project value falls between £38,000 and £48,000. The boroughs we build side returns most often: Clapham, Battersea, Balham, Tooting, Wandsworth, Putney in SW London; Crystal Palace, Lewisham, Forest Hill, Dulwich in SE London. Each borough has different typical side return widths (Crystal Palace is wider at 1.2-1.5m; tighter at 0.9-1.1m in some Clapham terraces) and different council requirements. Crittall-style or Slimline aluminium glazing is the standard glazing on the new external wall, with structural steel installed at the level of the existing kitchen ceiling to remove the load-bearing wall between the kitchen and the new side return space.
Accreditations and standards for side return work
Side return extensions trigger Party Wall Act 1996 requirements on virtually every project because the new structure shares a boundary wall with the neighbouring property. We serve Party Wall Notices on the adjoining owner at least two months before work starts and coordinate the appointment of an Agreed Surveyor where the neighbour dissents. Surveyor fees are typically £750-£1,500 and are paid by the homeowner doing the work. Structural steelwork is designed by our chartered structural engineer with calculations submitted to Building Control. Steel beams are typically 152x152 UC sections for standard side return openings, larger for wider openings. Padstones (concrete or brick) are designed to spread the load across the existing brickwork. Glazing is FENSA-registered with thermal performance to U-value 1.2-1.4 W/m²K. NICEIC electrical certification covers all new circuits to BS 7671. Building Control sign-off includes inspections at foundation, drainage, steelwork, insulation, and completion stages. We're CHAS-certified for site safety and carry £5 million Public Liability insurance.
How we deliver side return extensions
Survey through handover by one project manager. The project manager serves party wall notices early, coordinates the structural engineer's calculations, manages the steelwork delivery and crane lift, and runs the trade schedule. Fixed-price contracts. The quote includes structural engineer fees, party wall surveyor coordination, FENSA registration, Building Control fees, and any conservation area applications. The price doesn't change unless the specification does. Neighbour management. Side return extensions affect the neighbour more than most extensions — shared wall structural work, new glazing visible from their garden, scaffolding access. We manage the relationship proactively: notice served early, drawings shared, work hours respected, site cleaned daily. We operate from Unit 1 Limes Avenue, Anerley, London SE20 8QR. Companies House number 12721034. 57 verified Google reviews averaging 4.5 out of 5 stars.
Free tools for planning your project
No email required. Get instant estimates and planning answers before you book a consultation.
Side Return Cost Calculator
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Listed Check
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Planning Risk
Traffic-light check of every planning restriction at your postcode: listed buildings, conservation areas, Article 4 directions, Tree Preservation Orders, flood zones. Live data from Planning.data.gov.uk.
Recent Side Return Extensions Projects
Side Return Extensions across South East London
What Our Customers Say
“All Well managed our project from start to finish. The fixed-price contract meant no surprises, and the result is stunning.”
Verified Customer
“Professional team, clean site, and they handled all the paperwork. Would recommend to anyone.”
Verified Customer
“Great communication throughout. They kept to the timeline and budget exactly as quoted.”
Verified Customer
Accredited & Certified
Frequently Asked Questions
- What is a side return extension?
- A side return extension fills in the narrow alleyway — typically 0.9 to 1.5 metres wide — that runs along the side of most Victorian and Edwardian terraced houses in London. By building over this passage and opening up the dividing wall with a structural steel beam (typically a 203x203 UC or similar RSJ sized by a structural engineer), you can add 30-50% more width to your ground floor kitchen without losing any garden space. The result is usually a bright, open-plan kitchen-diner that feels dramatically larger than before, often gaining 8-15 square metres of usable floor area. Side returns are one of the most popular home improvements in boroughs like Lewisham, Dulwich, Peckham, and Greenwich because they work within the existing footprint and typically fall under permitted development, meaning no planning application is needed. We have run side return extensions across South London since 2020.
- Do side return extensions need planning permission?
- Most side return extensions fall within permitted development rights under the Town and Country Planning (General Permitted Development) Order 2015, meaning no formal planning application is required. The extension must not exceed 3 metres beyond the original rear wall for terraced houses, must stay below 4 metres in height at the eaves, and must not cover more than half the total garden area. If your property is in a conservation area — such as those in Dulwich, Blackheath, or parts of Greenwich — you may face additional restrictions on visible glazing, materials, and roof design. Listed buildings always require Listed Building Consent, which typically adds 8-12 weeks to the approval timeline. We assess all of this during the free site visit and apply for a Lawful Development Certificate (approximately £103 application fee) if you want formal written confirmation from the council that your extension is permitted. Around most of our side return projects proceed under permitted development.
- How much does a side return extension cost?
- A standard side return infill in South East London typically costs between £35,000 and £45,000. This includes structural steelwork to open up the kitchen wall, new foundations (typically strip foundations to 1 metre depth), roofing with glazing such as a flat glass roof or roof lantern for natural light, full insulation to current Building Regulations Part L standards, electrics, plumbing, plastering, and decoration. If you combine the side return with a rear extension to create a wraparound layout, expect £45,000-£65,000 depending on the total floor area. Crittall-style glazing from manufacturers like Steel Window Association members adds a premium of around £3,000-£5,000 over standard powder-coated aluminium frames. Kitchen unit fitting is quoted separately unless you want us to supply and install. We provide a fixed-price quote after the site visit — these figures are based on side return projects completed across South London boroughs since 2020.
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