House extensions in Clapham.
Clapham · SW4 · Clapham bespoke joineryCompleted work, photograph
Side returns and rear kitchen extensions for Clapham houses. Lambeth’s rules designed in, then built by one team.
Extending a Clapham house to the garden.
- Side returns
- Glazed and lightweight, Lambeth asks
- £160k to £250k
- A rear kitchen extension, cost guide total
- 7 days
- A budget estimate, typically
NU Projects is a design and build company in Fulham SW6, founded in 2010. We handle house and kitchen extensions in Clapham SW4, under one contract. A rear extension runs £235 to £460 a sq ft, construction only. A side return runs £215 to £425 a sq ft. Call 020 7731 6841, and a budget estimate typically follows within seven days.
Most Clapham houses are Victorian terraces, with a return at the back.
The usual move is a side return, or a full-width rear extension.
Lambeth wants infills glazed and lightweight, so the old return still reads.
Much of Clapham is conservation area, where the rules tighten.
We draw it, price it and build it under one contract.
What the council allows in Clapham.
- Council
- London Borough of Lambeth, under its Local Plan adopted in September 2021.
- Policy Q11
- Extensions are supported in principle, if they stay subordinate to the house.
- Side returns
- Infills should look glazed and lightweight. In a conservation area, stop one brick short of the corner.
- Full width
- Full-width rear extensions are normally supported. Wraparounds are resisted in conservation areas.
- Permitted development
- A single-storey rear extension can reach 3 metres on a terrace without planning. Prior approval can allow 6.
- Wandsworth side
- Near Clapham Junction, Wandsworth’s Policy LP5 applies instead. We confirm the borough first.
Source: Lambeth Local Plan 2021, Policy Q11, and the Lambeth Design Guide, Part 4 (2023). Read on 5 October 2026. Policies change, so we read them again for your address.
Kitchens we have built nearby.
Clapham·Joinery
Clapham bespoke joinery
A Clapham house, its kitchen and joinery made by Cochrane Bespoke.
See the project
Chelsea·Townhouse
Chelsea basement and extension
A rear kitchen extension and a new basement, in Chelsea.
See the projectCompleted work, photographs
What house extensions costs in Clapham.
£235 to £460a sq ft, construction only. Our rear extension band.
£215 to £425a sq ft, construction only. Our side return band.
£140k to £220kA side return extension. A project total, from our 2026 cost guide.
Most Clapham extensions sit in the luxury or high-end tier.
The bands are rates per square foot, construction only. The guide figures are project totals.
Fees, party wall costs, contingency and VAT sit outside both.
What Clapham owners ask about extensions.
In Clapham
Extensions nearby
- House extensions across London
- House extensions in Fulham
- House extensions in Chelsea
- House extensions in Kensington
- Wandsworth, Putney and Barnes
- Fulham
- Chelsea
Further reading, from the journal
Do I need planning permission for a Clapham side return?
Usually, yes. Side extensions are not permitted development in a conservation area.
Outside one, it depends on the house and the design.
We check the address before anything is drawn.
How far can I extend at the back without planning in Clapham?
Three metres on a terraced or semi-detached house, single storey.
Prior approval can stretch that to six metres.
Neither route applies the same way in a conservation area.
What does Lambeth want a side return to look like?
Glazed and lightweight, so the original return stays dominant.
In a conservation area, it stops one brick short of the corner.
Making the return itself full width is generally resisted.
Is a wraparound extension allowed in Clapham?
Lambeth resists them on heritage buildings and in conservation areas.
Elsewhere, a well designed one can be supported.
A side return plus a rear extension often achieves the same room.
What does a Clapham kitchen extension cost?
A rear kitchen extension is typically £160k to £250k as a whole project.
A side return is typically £140k to £220k.
Send the address and we price it properly.
Tell us about your home in Clapham.
Your name and one way to reply are enough. It goes straight to the studio.
- Already have an architect or designer? We build to their design. Working with your designer
- An NDA on request, and your home is never published without your consent. How we work in confidence