House Extensions Crouch End
Single storey rear and double storey extensions in Crouch End, 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 on Crouch End's Victorian and Edwardian terraces, from rear and side-return additions to full wrap-arounds. We handle the foundations, the steelwork, the roof and the fit-out, and guide you through permitted development or a planning application to Haringey Council.
In Crouch End, 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 Crouch End: 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 Crouch End
Crouch End range: choose above
Side return extensions on Crouch End terraces
The side return, that narrow strip of land beside the rear closet wing, is the classic Crouch End extension. Filling it in widens a cramped galley kitchen into a bright open-plan space running the full width of the house. We dig new foundations beside the existing wall, allowing for any nearby trees, then support the flank and the floor above on steel beams sized by a structural engineer.
A single-storey rear extension often falls under permitted development, including in a conservation area, but this is not guaranteed. In a conservation area a side-return infill counts as a side extension and needs planning permission, an Article 4 direction can remove the rear allowance too, and a previous addition or a larger scheme can mean a full application is required. Flats have no householder permitted development at all. We check the position for your specific address, coordinate the drawings, and apply to Haringey Council where planning permission is needed.
Housing in Crouch End
Take the 10,270 or so homes the valuation list gives Crouch End: 76% flats, 24% houses, 66% from before 1919, 4% interwar and 30% post-war. Where most homes are flats, a flat in Crouch End has no householder permitted development rights, so extending one needs planning permission and the freeholder's consent.
Rear extensions seen across Crouch End gardens from the street
The Crouch End appraisal says careful consideration should be given to the effect of rear dormers and extensions where there are views across rear elevations from nearby streets. On a Crouch End corner plot, or where a road rises behind a terrace, the back of the house is on show, and an extension there is judged partly as a street view. Haringey designated the Crouch End conservation area on 25 October 1974, and within it single-storey extensions more than 3 metres beyond the back wall of a house, or 4 metres for a detached house, need planning permission. A shorter single-storey rear extension on a house can still be permitted development unless an Article 4 direction removes it.
Before an architect draws the rear, walk the nearby streets and photograph the back of the terrace from wherever it can be seen. Those photographs tell the designer how much of the roofline, the brick and the glazing is public, and they answer the appraisal's question before it is put. The drains need the same early look. Where development is within 3 metres of a public sewer, Haringey building control says build over permission from Thames Water is needed before starting work, and a CCTV survey of the rear run settles that during design.
Double storey extensions in Crouch End homes
Where a family needs more than a wider kitchen, a double-storey rear extension adds a bedroom or bathroom above the new ground-floor space. On a Crouch End terrace this usually means deeper foundations, careful matching of the original brick, and a roof that ties neatly into the existing closet wing. A two-storey addition beyond the modest permitted development limits will generally need planning permission from Haringey Council.
Because these terraces are joined on both sides, party wall matters nearly always arise, whether from excavating close to the boundary or building off a shared wall. You serve the notices as building owner (or your surveyor does), using the drawings we supply; we install the steelwork and manage the trades from groundworks through to the final decoration. Building regulations approval and inspections run alongside any planning consent, so your extension is both permitted and properly constructed before you move back in.
Kitchen extensions in Crouch End
76% of homes in Crouch End are flats, and a flat has no householder permitted development, so a ground-floor flat's kitchen extension needs planning permission from Haringey Council and the freeholder's consent. Most kitchen extensions here are on the 24% of homes that are houses. The fit-out is priced on its own page, kitchen renovation in Crouch End; the build figures are in the table above.
- Party wall process explained, and the extension built to the award
- Roof works and structural alterations at roof level
- Drawings and the structural engineer's design coordinated for you
VOA Council Tax stock of properties, March 2025, for Crouch End West, Crouch End East and Hornsey Vale. Counts rounded by the VOA.
Why Crouch End Homeowners Choose GS Renovation
Homeowners across Crouch End trust GS Renovation to take an extension from first sketch to finished room. We know how N8 terraces are built, we manage the Haringey planning and building control routes, and we coordinate the work around the party wall award, steelwork and fit-out with one team. Our founder's 30+ years of experience keeps the project on track and tidy.
- Programme planned around party wall notice periods before excavation near a neighbour
- Free follow-up visit after completion if anything needs attention
- Weathertight shell reached before the fit-out begins
Reviewed jobs near Crouch End
1 MyBuilder review from Hornsey, with each customer's own job title:
- New Kitchen Assembly & Others for Interior Designer, Hornsey, 5 Jan 2022 (5 out of 5)
Read all 31 on our reviews page.
Built a new extension at rear of property. Laid foundations, drainage, raised floor, new roof and completed all fixtures and interior decoration…
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…
We loved working with George and Ibrahim and would highly recommend them. They have done splendid job on our new kitchen refurb which including new…
FAQ
Frequently Asked Questions about House Extensions Crouch End
How do you price house extensions in Crouch End?
GS Renovation prices house extensions in Crouch End project by project, never by the day, against £2,000 to £2,800 per m² for a rear extension (indicative). After the N8 survey the figure is built up from labour, materials, the engineer's design, and the Haringey Council building control fee, each priced in the order the work runs: the planning route is confirmed before drawings, and footings inspected before concrete.
Will my Crouch End extension need planning permission or is it permitted development?
Many single-storey rear extensions in Crouch End are permitted development, including in a conservation area, but a side-return infill in a conservation area, a two-storey addition, a scheme beyond the size limits or an Article 4 direction can require a planning application to Haringey Council. We assess your specific N8 address, tell you which route applies, and coordinate the drawings and submission if permission is needed.
Can I extend the ground floor flat I own in Crouch End?
Only with planning permission. Permitted development rights apply to houses, not flats, so an extension to a ground floor flat needs a full application to Haringey Council. The freeholder's written consent is also needed, as the extension changes the building, and building regulations apply as for any extension. That is settled before any design work.
Does my Crouch End house extension affect the neighbour's wall?
If you build on or near the boundary, usually yes. New trenches close to their house, within 3 metres and lower than its footings, carry a one month notice under the Party Wall Act, while work on the shared wall itself needs two months. Should the neighbour refuse consent, surveyors produce an award, and no digging starts until it is agreed.
What happens to the gully in my Crouch End house side return when we extend?
It is usually relocated. Where a Victorian house has an open gully in the side return taking the kitchen waste, it sits right where the new floor goes. The drain is rerouted to meet Part H, and if the run serves more than one property it becomes a public sewer, needing the water company's consent to build over.
How deep are extension foundations near trees in Crouch End?
Deeper than standard, where clay and trees combine. Clay shrinks and swells with moisture, and nearby trees make that worse, so the engineer or building control may require deeper trenches or a different foundation type. The trench is inspected before concrete goes in, and the depth is confirmed when the ground is open.
Does a side return infill in the Crouch End conservation area need planning permission?
Yes. In a Haringey conservation area any extension at the side of a house needs planning permission, and the Crouch End conservation area has been designated since 25 October 1974. A side return infill is that kind of extension. Make a householder planning application, and design the roof and glazing with the appraisal's point about views across rear elevations from nearby streets in mind.
How is the building control charge for a Crouch End extension worked out?
By floor area bands. For an extension of 10 to 40 square metres, Haringey's charges table gives one building notice charge, or a plan charge plus an inspection charge on the full plans route. Measure the internal area once the planning drawings settle. A Crouch End extension that grows during planning, for example to wrap round the closet wing, may move to a different line of the table.
Can a Crouch End rear extension be built over a shared drain?
Only with the right permission where a public sewer is close. Haringey building control says development within 3 metres of a public sewer needs build over permission from Thames Water before work starts. A drain serving more than one house can be a public sewer, so have the run traced and surveyed during design. Shifting the footprint slightly is sometimes simpler than building over.
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