House Extensions Kentish Town
Single storey rear and double storey extensions in Kentish Town, planning, structure and build under one contract.
- Rated 4.9 from 31 reviews on MyBuilder
- Single-storey rear extension from £40,000
- Free site survey, itemised quote
GS Renovation builds extensions throughout Kentish Town, adding space to the Victorian and Edwardian terraces of NW5 between Tufnell Park and Camden Town. We build rear, side-return and wrap-around extensions, handling foundations, steel, roof and full fit-out as a single managed project.
In Kentish Town, a single-storey rear extension typically starts from £40,000, or £2,000 to £2,800 per m² (indicative London ranges, Architecture for London, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Kentish Town: the structural engineer we appoint designs the structure, we build it, and building control signs it off.
Price guide
| Work | Indicative London range |
|---|---|
| Single-storey rear extension | from £40,000 |
| Rear extension, per m² | £2,000 to £2,800 |
| Side return, per m² | £2,400 to £3,200 |
| Wraparound, per m² | £2,400 to £3,200 |
| Double storey, per m² | £1,800 to £2,600 |
| Basement extension | see the basement page |
Indicative London ranges (Architecture for London, Resi, MyBuilder and Checkatrade, 2026), not a quotation. Prices checked September 2026. Full breakdown: Extension Costs & Planning.
Quick estimate for Kentish Town
Kentish Town range: choose above
Side-return extensions on Kentish Town terraces
The side return is the classic Kentish Town extension. Most bay-fronted terraces here have a narrow alley of wasted ground beside the rear closet wing, and filling it turns a dark galley kitchen into a wide open-plan kitchen-diner. We dig and pour new foundations next to the existing wall, install the steel to carry the old external wall, tie the new roof into the closet wing and rebuild so the finished space feels original rather than bolted on.
Working in tight NW5 back gardens with limited rear access takes planning. We often barrow materials through the house or over neighbouring boundaries, protect the existing brickwork and manage spoil removal carefully on residential streets. Because a side return usually meets a shared boundary, party wall agreements with the neighbours are part of the job, and you serve the notices and appoint surveyors where they are needed.
Housing in Kentish Town
Of the 8,940 homes the valuation list records in Kentish Town, 44% were built before 1919, 4% between the wars and 52% since 1945; 87% are flats and 13% are houses. Where most homes are flats, a flat in Kentish Town has no householder permitted development rights, so extending one needs planning permission and the freeholder's consent.
Trees and pre-planning advice before a Kentish Town extension
If your house is in the Kentish Town Conservation Area, check the trees before the footprint is drawn. Camden requires six weeks' notice before tree work in a conservation area, for any tree with a trunk diameter of more than 75mm at a height of 1.5 metres. On a narrow terrace plot the tree that matters may be in the neighbour's garden, overhanging the line of the new wall. Cutting back its branches for scaffold still needs the notice, so it goes in before the dig is booked.
Houses are 13% of Kentish Town homes, so a two storey extension here is a project open to relatively few owners. In a conservation area a two storey rear extension needs planning permission in any case. It is also the kind of scheme Camden's Level 2 homeowner pre-planning application advice is set up for, since that level covers multiple or more complex works such as two storey rear extensions. Take drawings that already show the neighbours' windows and the tree positions. A two storey addition on a terrace is judged on its effect next door, and that is where the meeting's time will go.
Planning and permitted development in Camden
Whether your Kentish Town extension is permitted development or needs a full planning application depends on the property. Many single-storey rear extensions fall under permitted development rights, but those rights do not apply to flats. In a Camden conservation area a single-storey rear extension can still be permitted development within its limits unless an Article 4 direction removes it, while side and two-storey extensions need permission, and any listed building, of which NW5 has plenty, needs listed building consent. We assess your specific house early so you know which route applies before any design work is committed.
Where a planning application to Camden Council is required, we work alongside your architect on the drawings and guide the build to match exactly what is approved. Separately, every extension needs Building Regulations sign-off covering foundations, structure, insulation, drainage and fire safety. We keep planning and building control clearly apart, arrange the inspections at each stage and hand over the certificates at completion.
Kitchen extensions in Kentish Town
87% of homes in Kentish Town are flats, and a flat has no householder permitted development, so a ground-floor flat's kitchen extension needs planning permission from Camden Council and the freeholder's consent. With so few houses here, the realistic kitchen gain in most Kentish Town homes is a better layout inside the flat rather than an extension. The fit-out is priced on its own page, kitchen renovation in Kentish Town; the build figures are in the table above. Double storey extensions belong to the few houses here.
- Wrap-around extensions and infills
- Levels, drainage and landscaping made good around the new build
- Side-return and rear extensions
VOA Council Tax stock of properties, March 2025, for Kentish Town West and Kentish Town East. Counts rounded by the VOA.
Trusted House Extensions in Kentish Town
Kentish Town owners choose GS Renovation because one team takes the extension from foundations to final coat, including the steel, the roof, the party wall matters and the fit-out. We understand Camden's conservation constraints and NW5 access challenges, we price transparently, and our founder's 30+ years on the tools means fewer surprises and a build that lasts.
- Weathertight shell reached before the fit-out begins
- Programme planned around party wall notice periods before excavation near a neighbour
- Our own trades on site rather than a chain of subcontractors
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
George always kept to commitments and arrived on time. He offered helpful suggestions during his initial visit and promptly provided a reasonably…
It's the second time I have hired George and he has been absolutely professional and the work he did resembles perfectly what I had in mind. Being an…
FAQ
Frequently Asked Questions about House Extensions Kentish Town
What should I budget for house extensions in Kentish Town?
A Kentish Town budget for house extensions should sit within £2,000 to £2,800 per m² for a rear extension (indicative) and add a contingency for what the NW5 survey cannot see. In purpose-built post-war housing the unknowns sit behind plaster and under floors, so GS Renovation prices what is visible and names the rest. The Camden Council building control fee belongs in the same budget.
Will my Kentish Town rear extension need planning permission?
Many single-storey rear extensions are permitted development, but those rights do not apply to flats. In a Camden conservation area side and two-storey extensions need permission, while a single-storey rear extension can still qualify unless an Article 4 direction removes it, and a listed building needs listed building consent; all of these are common in NW5. We check your specific house first so you know whether a planning application to Camden Council is needed or whether permitted development applies before design begins.
Does a Kentish Town extension on the boundary need a party wall notice?
Often. Digging foundations deeper than the neighbour's own, within 3 metres of their building, calls for one month's notice. Cutting into the party wall to bear a beam is a separate party structure notice with a two-month lead. The adjoining owner may agree or object in writing; an objection means surveyors prepare an award, and that has to be settled before the first trench is dug.
How do I get more daylight into a Kentish Town rear extension?
Through the roof. Rooflights or a lantern bring light deep into the plan, which matters behind a terrace where the rear of the house faces another building. Part L sets insulation standards for the extension, so large areas of glazing have to be balanced by better performance elsewhere. The roof design is agreed with building control before it is built.
Can we stay in our Kentish Town house while the extension is built?
Usually, for most of the build. Foundations, walls and roof go up outside while the existing back wall stays closed. The disruptive point is breaking through: the opening is formed with steel once the new structure is weathertight, and for those days the kitchen or rear room may be out of use. We plan that stage around your household.
How is a new Kentish Town extension joined to the existing house?
By forming an opening in the rear wall on engineer-sized steel, and only after the extension shell is up and weathertight. The structure above is propped, the wall comes out in stages and the beam sits on padstones. Building control inspects the steel before it is cased. Floors, insulation and finishes are then brought through so old and new meet cleanly.
Will a Kentish Town extension be liable for the Community Infrastructure Levy?
Only if it crosses a threshold. Camden's levy applies to all proposals which add 100 square metres of new floorspace or an extra dwelling. A single rear extension to a terrace is normally well below the floorspace figure. A scheme that combines a rear extension, a side infill and a new lower floor should be totalled early, and one that creates a separate flat is caught whatever its size. Where the levy does apply, ask about reliefs before work starts.
Which building control band covers a Kentish Town side-return extension?
Camden's Schedule 2 residential charges set one line for any extension of a dwelling, including basements, with a total floor area over 10m2 and up to 60m2. A single-storey rear or side-return extension on a terrace usually falls inside it. Knowing the band early lets the building control charge sit in the budget from the start, rather than arriving as a surprise with the application.
What should the heritage statement for a Kentish Town extension cover?
Camden requires one with any planning application for alterations in a conservation area, describing the significance of the heritage assets affected. For a rear extension in the Kentish Town Conservation Area that means the house, the terrace it belongs to and how the rear elevations read from neighbouring gardens. The architect writes it, but photographs of the existing rear, taken before the scaffold goes up, make it easier to write and to check.
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