Side Return Extension London and Hertfordshire
Unlock the hidden space in your side return with a beautifully designed extension by LCCL Construction. We specialise in side return infills on Victorian and Edwardian terraced houses across London and Hertfordshire. Full design and build from £35,000. LABC Award Winners 2024. Over 200 reviews rated 4.7 out of 5.
LABC Awards
Winners 2024
200+ Reviews
4.7 / 5 Rating
NFB Members
LABC Partners
What Is a Side Return Extension?
A side return extension infills the narrow alleyway — known as the side return — that runs along the side of many London houses. This underused strip of land, typically 1 to 2 metres wide, is converted into additional internal floor space that dramatically widens the ground floor layout.
Side return extensions are particularly popular on Victorian and Edwardian terraced houses across London, where the original kitchen is often narrow and separate from the dining room. By infilling the side return and removing the internal wall, homeowners create a single wide open-plan kitchen-diner that transforms how the ground floor works.
LCCL Construction specialises in side return extensions across London and Hertfordshire. Based in Finchley, London N3, we have designed and built side return extensions on period properties throughout North London, South London, East London, West London and Hertfordshire. With over 20 years of experience, 200+ reviews rated 4.7/5 and LABC Awards Regional Winners 2024, we deliver side return extensions to the highest standard.
How Much Does a Side Return Extension Cost?
Side return extension costs in London typically range from £35,000 to £55,000 for a standard side return infill with design and build. Costs increase for larger side returns combined with rear extensions (wraparound schemes), which typically cost £60,000 to £100,000. Estimated cost. depending location, final drawings, structure drawings, alterations, costs subject to change.
Factors that affect cost include the length of the side return, the amount of structural steelwork required to open up the interior, the specification of glazing (roof lights, glass roof sections), and the level of finishing.
Prices include architectural design, structural calculations, building regulations, construction, electrics, plumbing, plastering and decoration. Get an instant quote at lcclconstruction.co.uk or call 020 8037 7332.
Planning Permission for Side Return Extensions
Many side return extensions fall under permitted development rights, but this depends on the size of the side return, its proximity to boundaries and the local planning authority. Some London boroughs have Article 4 directions that remove permitted development rights in certain streets or conservation areas.
Key considerations include: the extension must not exceed 4 metres in height, must not extend beyond the rear wall of the original house (unless combined with a rear extension), and must not result in more than half the garden being covered by extensions.
LCCL Construction handles all planning applications and building regulations as part of our service. We check permitted development eligibility for your specific property and advise on the best approach.
Side Return Extension Design Ideas
The most effective side return extensions use the full width of the new space to create a light-filled open-plan kitchen-diner. Popular design features include:
Glass roof over the side return section to create a light-filled transition between old and new.
Structural glazing to maintain visual connection with the side passage.
Slim-profile steel frames that maximise the opening between the original house and the new space.
Continuous rooflight running the length of the side return.
Matching internal finishes — flooring, ceiling height, lighting — to make old and new feel like one space.
Side return extensions work particularly well on Victorian terraced houses in areas such as Finchley, Muswell Hill, Crouch End, Highgate, Stoke Newington, Hackney, Clapham, Putney and across London.
What Is Included?
Our design and build service covers everything: free consultation, measured building survey, architectural design, planning and building regulations, structural calculations, party wall agreements, all construction work, electrics, plumbing, plastering, decoration, building control sign-off and optional 10-year LABC warranty. One company, one point of contact, from start to finish.
How Long Does a Side Return Extension Take?
A side return extension typically takes 12 to 24 weeks to build. The full timeline from consultation to completion is usually 5 to 7 months:
Timelines may be longer for larger or more complex projects involving significant structural alterations.
Areas We Cover
LCCL Construction designs and builds side return extensions across London and Hertfordshire including Barnet, Finchley, Hendon, Muswell Hill, Highgate, Hampstead, Crouch End, Stoke Newington, Hackney, Islington, Camden, Clapham, Putney, Wandsworth, Ealing, Southgate, Enfield, Edgware, Borehamwood and surrounding areas. Call 020 8037 7332 to book a free consultation.
What Our Customers Say
"Reliable, fast, trustworthy and very organised. Our house extension looks great and we would recommend LCCL Construction to anyone looking for a quality builder in London." — Alex Gray, Google Reviews, 5/5
"In just over 6 months LCCL managed to transform my 1900s mid-terrace house into a clean and modern living space with a full rear extension, loft conversion and complete renovation." — Matt EL, Houzz, 5/5
Frequently Asked Questions
How much does a side return extension cost in London?
Side return extension costs in London typically range from £35,000 to £55,000 for a standard side return infill with full design and build. Costs increase for larger schemes that combine a side return with a rear extension (wraparound), which typically cost £60,000 to £100,000. Estimated costs, highly dependable on location, final drawings, structural drawings, alterations, finishing types. Costs subject to change.
Do I need planning permission for a side return extension?
Many side return extensions fall under permitted development rights, but this depends on the size, proximity to boundaries and your local planning authority. Some London boroughs have Article 4 directions that remove permitted development in certain areas. LCCL Construction checks eligibility for your specific property.
Is a side return extension worth it?
Yes. A side return extension is one of the most cost-effective ways to transform a narrow London terraced house kitchen into a spacious open-plan kitchen-diner. The additional width created by infilling the side return makes a significant difference to how the ground floor feels and functions.
Can you combine a side return extension with a rear extension?
Yes, this is called a wraparound extension. It combines a side return infill with a rear extension to create an L-shaped addition that maximises the ground floor footprint. LCCL Construction designs and builds wraparound extensions across London and Hertfordshire.
How long does a side return extension take?
A side return extension typically takes 8 to 14 weeks to build. The full project timeline including design, planning and construction is usually 4 to 6 months from initial consultation to completion. Can take longer to build it is dependable on type, location, structure, finishing and alterations.
How do I get started?
Call us on 020 8037 7332, book a free consultation at lcclconstruction.co.uk, or get an instant quote online.