Single and double storey extensions in Islington. Trusted, professional, 30+ years' hands-on experience.
GS Renovation designs and builds extensions across Islington, from Highbury's Victorian terraces to converted warehouses near Old Street and Clerkenwell. With more than 30 years working in N1, N5, N7, N19 and EC1, we handle foundations, steelwork, roofing and fit-out, and we tell you straight whether your project is permitted development or needs planning permission from Islington Council.

The side return on an Islington Victorian terrace is often dead space, a narrow strip beside the rear closet wing that lets little light in. Filling it, and extending across the back, turns a cramped kitchen into a wide, open living space. We dig and pour foundations to suit the ground, install the steel beams that carry the existing rear wall, and tie the new roof and glazing into the original house neatly.
Because these terraces sit shoulder to shoulder, a rear extension almost always involves the party wall, so notices go to the neighbours before groundworks begin. Many single-storey rear extensions fall under permitted development, but conservation-area status across much of Islington, or a listed building, can remove those rights and require a planning application. We assess your specific address early, so you know which route applies before any design is finalised.
On the larger plots around Highbury Fields and Holloway, a double-storey or wrap-around extension can add a proper kitchen-diner below and a bedroom or bathroom above. These schemes carry more load, so the steel design and foundations matter even more, and they almost always need a full planning application to Islington Council rather than falling under permitted development. We handle the drawings, the structural calculations and the build under one roof.
Warehouse and Clerkenwell conversions play by different rules. Many are leasehold flats where structural change needs the freeholder's licence to alter and coordination with the managing agent, and building-management rules on sound insulation between flats still apply. We work within those constraints, keeping neighbours informed and the block's conditions met. Whether your extension is a house at the back or a reconfiguration inside a converted building, we build to Building Regulations and get it inspected.
Islington homeowners choose GS Renovation because we deliver the whole extension, design, groundworks, steel, roof and finish, with one team accountable throughout. After 30-plus years across N1, N5, N7 and N19, we know the borough's terraces, conservation areas and party wall demands. We guide you honestly on permitted development versus planning, and we build to last.
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
We price each Islington project individually, because the cost of house extensions depends on far more than floor area. After a free survey you receive a clear written breakdown with no hidden extras. Call 07472 424 226 or email info@gsrenovationltd.co.uk. 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.
How long house extensions takes in Islington depends on the size of the job, but we always agree a programme before starting and stick to it, keeping you informed from the first day to the last.
Islington homeowners choose GS Renovation for reliability and quality. We are fully insured, building control compliant where needed, and bring over 30 years of hands-on experience to every house extensions project, with a single point of contact throughout.
Many single-storey rear extensions in Islington 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 Islington's homes are period, Georgian and listed properties, and we renovate them regularly. We plan each house extensions around their particular characteristics, such as conservation and listed-building rules, solid walls and original period features, so the result suits the building and meets building control.
It depends on your property. Many single-storey rear extensions are permitted development, but large parts of Islington are conservation areas, and if your home is listed or in one, those rights are often restricted or removed, meaning a planning application to Islington Council. Double-storey and wrap-around schemes usually need permission too. We check your exact address before designing so there are no surprises.
We do. GS Renovation covers all of Islington and the N1 area and the wider North London. Call 07472 424 226 and we will confirm we work on your road.
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 Islington. 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 Islington and the surrounding areas. Explore a nearby location:
Contact GS Renovation today for a free, no-obligation quote for house extensions in Islington.
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