Design and build · Surrey
House extensions in Leatherhead, designed and built by one team from our base in New Haw, about 8 miles away.
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10 to 14 weeks
to build a single-storey rear extension
District Council decides planning
Conservation areas
Leatherhead and Fetcham
8 miles
from our base in New Haw
Building in Leatherhead
Extensions in Leatherhead work with a wide range of houses: early-1900s houses on Fairfield, Highlands and Kingston Roads, inter-war houses at Givons Grove, post-war homes along Cleeve and Copthorne Roads and, across the Mole, Fetcham's detached and semi-detached houses. Construction time depends mostly on scale: 10 to 14 weeks is usual for a single-storey rear extension, 16 to 24 weeks for a double-storey or wrap-around one.
Mole Valley's Design Guidance for House Extensions SPD (2025) covers overlooking and single- and two-storey extensions, and the Leatherhead and Bookham & Fetcham Design Codes add detail for householder applications. In the Leatherhead and Fetcham conservation areas, side and two-storey rear extensions need planning permission, and Article 4 controls cover parts of the Leatherhead conservation area. Near the River Mole, which reached a record 3.74 metres at the Leatherhead gauge in December 2013, an extension's floor level is set with the flood information in mind, and the high water table can affect foundations. Most of the district's countryside is Metropolitan Green Belt, and for a house in it an extension is expected to stay proportionate to the original building. Where an application is needed, a standard decision takes 8 to 13 weeks; the route itself is settled for each house before design.
What we build
Push out into the garden to create a bright kitchen-diner or family room, often achievable under Permitted Development.
Add space across two floors at once, gaining extra living space below and a bedroom or bathroom above.
Combine a rear and side-return extension into one L-shaped footprint for a dramatic increase in ground-floor space.
Reclaim the narrow, underused alley beside Victorian and Edwardian homes to widen and flood the rear with light.
Open the back of the house into a single sociable hub built around cooking, dining and family life.
Roof lanterns, rooflights, bi-fold and sliding doors that pour daylight deep into the new space.
Our nearest finished extension
Greenwich, London · about 19 miles from Leatherhead
Opening the rear of a 1930s semi into one room meant removing a load-bearing wall between the existing kitchen and the new extension, on a site where a narrow side passage was the only route for materials in and spoil out. The new ground-floor shower room also had to be formed within the existing rear lobby, well away from the original layout's plumbing.
The structural opening was formed with a steel beam cased into a shallow flush bulkhead that follows the line of the removed wall, keeping the ceiling clean and the sightline from kitchen to garden completely open. Deliveries were sequenced in small daily loads through the side passage to keep the neighbouring boundary clear, and services for the new shower room were routed within the extension's floor build-up so no boxing-in was needed in the finished rooms.
View this projectExtension FAQs
Straight answers on house extensions in Leatherhead.
In the Leatherhead and Fetcham conservation areas, side and two-storey rear extensions always do. Elsewhere, a modest single-storey rear extension can often proceed under Permitted Development, and prior approval, which takes around 6 to 8 weeks, can allow a deeper one. Anything beyond those limits needs a full application, with a standard decision taking 8 to 13 weeks.
Free Cost Proposal
Tell us about the project. We'll arrange a free site visit, then send a clear, itemised Cost Proposal.
“The attention to detail and absolute financial transparency provided by Grand Innovations completely redefined our expectations of what a home renovation could be. High standard of work, the extension is beautiful and has added so much value onto our home. Really appreciated the weekly billing, rather than a big amount upfront.”
