Single and double storey extensions in Borough. Trusted, professional, 30+ years' hands-on experience.
GS Renovation designs and builds house extensions throughout Borough and SE1, adding space to the Victorian and Edwardian terraces that define this corner of Southwark. Drawing on more than 30 years of building experience, we handle rear, side-return and wrap-around extensions, from homes near the South Bank to the terraces stretching towards Bermondsey and Peckham.

The classic Borough extension fills the side return, the narrow strip of yard beside the rear closet wing that so many of these terraces carry. Infilling it widens a cramped kitchen into a bright open-plan space, often combined with a rear extension to push further into the garden. We handle the foundations and groundworks, the steel beams that carry the old outside wall, the roof works and the full fit-out as one continuous project.
Because these are solid-wall period houses on tight urban plots, we plan every extension around the existing closet wing, the drainage runs and the party walls with neighbours either side. We match brickwork and detailing where it matters, and we keep the works tidy and contained on the restricted SE1 sites that are typical here. One team stays responsible from the first dig to the final coat of paint.
Whether your extension needs a full planning application to Southwark Council or falls under permitted development depends entirely on the property, its size and whether it sits in a conservation area. Many single-storey rear extensions on Borough terraces proceed under permitted development, while larger, double-storey or wrap-around schemes usually require permission. We assess your home honestly and tell you which route applies before you commit.
Alongside planning, the structural side is covered by building regulations, with building control inspecting foundations, steelwork and drainage as the extension goes up. And because you are digging and building close to the boundary in these terraces, the Party Wall Act almost always applies, so we help you serve notices on adjoining owners. We manage planning, building control and party wall matters together so nothing is missed.
Borough homeowners choose GS Renovation because one team takes an extension from design and groundworks through steelwork, roof and fit-out, with the planning, building control and party wall matters handled alongside. Over 30 years on SE1 terraces means we understand side returns, closet wings and tight plots, delivering extensions that feel part of the original house.
George was brilliant. Lovely bloke, very reasonably priced and a perfectionist to boot. He completed our small kitchen renovation with care and great attention to detail. I've already recommended him to others.
Splendid job on our new kitchen refurb, including new flooring, moving the services, installing RSJ and preparing space for new back doors… George was always friendly, communicative and has an excellent attention to detail, ensuring everything is finished to a high standard.
Giorgio is an excellent and intelligent workman, and with very reasonable prices!… He paid a lot of attention to detail that is not common at all, and the final result was immaculate. Highly recommended!
FAQ
The cost of house extensions in Borough depends on the size of the property, the specification and the scope of work. GS Renovation provides free, detailed and itemised quotations for every Borough project. Call 07472 424 226 or email info@gsrenovationltd.co.uk for a no-obligation estimate. As a rough guide, house extensions in London typically starts from roughly £40,000 for a single-storey rear extension and rises with size and specification (indicative London ranges, MyBuilder and Checkatrade, 2026). Your figure depends on the size, specification and condition of the property, which is why we survey before quoting.
We will give you an honest timescale for house extensions in Borough after surveying your home. Most projects run on a clear weekly programme, and we tell you up front about any lead times on materials or approvals.
With more than three decades of hands-on trade experience behind us, GS Renovation is a trusted choice for house extensions in Borough. You get one accountable team, transparent pricing, fully insured tradespeople and genuine aftercare on every project.
Many single-storey rear extensions in Borough fall under permitted development, but side returns, double-storey extensions and work in conservation areas usually need full planning permission. We assess your property and manage both the planning application and building control.
Yes. A large share of Borough's homes are Victorian and Edwardian terraced properties, and we renovate them regularly. We plan each house extensions around their particular characteristics, such as solid brick walls, rear closet wings, side returns and original period features, so the result suits the building and meets building control.
It depends on the property. Many single-storey rear or side-return extensions on Borough terraces are permitted development, but larger double-storey or wrap-around schemes, or homes in a conservation area, usually need a planning application to Southwark Council. We review your specific house first and advise honestly, then handle the application and the building regulations approval alongside it.
Yes, Borough is one of our core areas. We work on every street and the SE1 area and across the wider South London, so wherever your home is, call 07472 424 226 and we will confirm we can help.
Every Service, One Team
The same trusted team, 30+ years' hands-on experience and free, no-obligation quotes apply to every GS Renovation service in Borough. Explore what else we do locally:
Steel beam installation, RSJ and structural alterations.
Safe load-bearing wall removal with steel beam support.
Structural alterations, new openings and steel support.
Chimney breast removal with gallows bracket or beam support.
Open-plan kitchen, diner and living conversions.
Full refurbishments and whole-house renovations.
Bespoke kitchen design and installation.
Luxury bathroom and wet-room refurbishment.
Same Service, Nearby Areas
We carry out house extensions across Borough and the surrounding areas. Explore a nearby location:
Contact GS Renovation today for a free, no-obligation quote for house extensions in Borough.
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