House Extensions & Loft Conversions in Crouch End

LCCL Construction is a design and build company based in Finchley N3, working in Crouch End for over 20 years. One team, one contract: architects, structural engineers, project managers and builders coordinated by LCCL take your project from first sketch to handover.

Crouch End's Victorian and Edwardian terraces around the Broadway and Weston Park are classic side-return and rear-extension houses, with steep roofs that take rear dormers and L-shaped dormers. It was named among the best places to live in London in 2026 — demand for space here is high.

What it costs in Crouch End

The final figure depends on postcode, access and site conditions — the instant estimate applies your area. Guide ranges for 2026, design and build inclusive (architecture, structural engineering, planning or LDC, construction, project management and building control). Every project is surveyed and priced individually.

• Velux loft: £32,400 – £50,400 inc. VAT (£27,000 – £42,000 + VAT)
• Rear dormer loft: £56,400 – £80,400 inc. VAT (£47,000 – £67,000 + VAT)
• L-shaped dormer: £58,800 – £98,400 inc. VAT (£49,000 – £82,000 + VAT)
• Hip to gable: £60,000 – £114,000 inc. VAT (£50,000 – £95,000 + VAT)
• Mansard: £76,800 – £148,800 inc. VAT (£64,000 – £124,000 + VAT)
• Rear extension: £42,000 – £90,000 inc. VAT (£35,000 – £75,000 + VAT)
• Side return: £42,000 – £93,600 inc. VAT (£35,000 – £78,000 + VAT)
• Wraparound: £72,000 – £153,600 inc. VAT (£60,000 – £128,000 + VAT)
• Double storey: £90,000 – £198,000 inc. VAT (£75,000 – £165,000 + VAT)

Kitchen on top of the structure, supplied and fitted: +£9,000 – £87,360 inc. VAT (£7,500 – £72,800 + VAT) depending on size and specification. Basements: cellar refit £54,000 – £114,000 inc. VAT (£45,000 – £95,000 + VAT), lowering £114,000 – £216,000 inc. VAT (£95,000 – £180,000 + VAT), new dig £216,000 – £360,000 inc. VAT (£180,000 – £300,000 + VAT)+. New build: £2,200 – £4,500 per sqm (zero-rated for VAT).

Recent LCCL projects near Crouch End

Uplands Road, Crouch End N8 — double-storey extension

A two-storey extension on a 1930s semi in Crouch End: open-plan kitchen below, a new bathroom and study above, finished with Lusso Stone, Buster + Punch and column radiators.

See the project

Also nearby: Cumberland Road, Wood Green N22 (l-shaped loft, 2022) · Manor Park Road, East Finchley N2 (side return extension, renovation, 2024).

Planning in Crouch End

Haringey; the Crouch End conservation area covers the centre, so rear dormers and extensions there need planning permission; streets outside it usually proceed under permitted development. Party wall awards on both sides are the norm on terraces.

Permitted development in Crouch End: what goes ahead without a planning application

Usually permitted development outside the conservation area. Haringey has no Article 4 direction in Crouch End (only the Rookfield Estate, Noel Park, Peabody Cottages and Tower Gardens carry one), but inside the Crouch End conservation area any roof addition and any rear extension over 3 m needs a planning application. On the streets outside it, lofts and single-storey rear extensions go ahead without one. Flats and maisonettes have no permitted development rights, whatever the street, and inside any conservation area a dormer or roof enlargement needs a planning application even where a single-storey rear extension within the limits does not.

On a house outside those streets, a rear dormer loft (40 m³ on a terrace, 50 m³ on a semi or detached house), a hip-to-gable, a single-storey rear extension of 3 m (4 m on a detached house) and a side-return infill are permitted development, and we apply for a Lawful Development Certificate on every one so the position is confirmed in writing. See our fixed-price permitted development projects — from £32,400 inc. VAT (£27,000 + VAT) for a Velux loft and £42,000 inc. VAT (£35,000 + VAT) for a 3 m rear extension, design and build inclusive, postcode dependent. Not sure whether your project needs a planning application? Planning check

Conservation areas and Article 4 directions in Crouch End

The Crouch End conservation area (designated 25 October 1974) covers the Clock Tower centre and the late-Victorian and Edwardian terraces and semi-detached villas around it, most built in the 1880s and 1890s. There is no Article 4 direction in Crouch End, so replacement windows and other front-facing works remain permitted development, but inside the boundary any roof extension, side extension or single-storey rear extension deeper than 3 m needs planning permission. The streets outside the conservation area — much of N8 towards Hornsey, Harringay and Stroud Green — normally take lofts and rear extensions under permitted development with a Lawful Development Certificate. Haringey’s only residential Article 4 directions are on the Rookfield Estate, Noel Park, Peabody Cottages and Tower Gardens.

The rules Haringey applies

Haringey decides householder applications against its Development Management DPD (adopted 24 July 2017) rather than a borough-wide extensions guide — there is no borough-wide extensions SPD. Policies DM9 and DM12 require extensions in a conservation area to complement the style, scale and materials of the host house. The council’s own guidance expects extensions to be subordinate, accepts the larger-home-extension prior-approval route (up to 6 m on a semi or terrace, 8 m on a detached house) outside conservation areas, prefers rear dormers set in at least 1 m from gable edges and 0.5 m from hips, and refuses roof-shape changes that harm the streetscape. Inside any Haringey conservation area planning permission is needed for a single-storey rear extension deeper than 3 m, any two-storey rear or side extension, any roof addition or alteration, cladding, and rooflights or solar panels projecting more than 150 mm.

Basements fall under policy DM18 (Residential Basement Development and Light Wells), which requires structural stability to be demonstrated; the council charges a higher pre-application fee for properties with a basement. Haringey has no numerical 45-degree rule — daylight and outlook are judged under DM1 and the BRE guide — so we design to clear a 45-degree line from the nearest neighbouring habitable-room window as a matter of course, which keeps most schemes out of a daylight report.

Fees and timescales

A householder application costs £548 (from April 2026, plus the Planning Portal service charge) and Haringey has eight weeks from validation to decide it. Written pre-application advice for a householder scheme is currently listed at £312 (express) or £498 with a meeting; a general enquiry is £103. Party wall notices run alongside planning: two months’ notice for works to a shared wall, one month for excavations within 3 m or 6 m of a neighbour’s foundations.

Building control

Haringey runs its own building control service and is an LABC member. We use the council inspector on every project. Typical inspection points are commencement, foundation trenches, oversite and damp-proof course, drainage before backfill, structural steels and joists before they are covered, insulation and fire-stopping before plastering, then completion. We book each one and hand you the completion certificate at the end of the job.

Anderson's advice: budget for the steelwork, not just the kitchen

Clients budget for kitchen units but forget the structural steelwork when opening up ground-floor walls. On a Victorian terrace that is typically £4,800 – £19,200 inc. VAT (£4,000 – £16,000 + VAT) for the load-bearing opening, depending on its width — we price it on every proposal so there is no surprise.

What our clients say

“Alex is super professional and on the ball at all times. He always thinks ahead and won't let you down. All his teams, from bricklayers, carpentry to electrics, roofing, tiling, painting, flooring and plumbing are excellent and hard working. They are all friendly yet professional. They are conscientious and want the job to be well done.”

— Ludovic, Reviews.io

As LABC Building Excellence Award winners in 2024 (Best Residential Extension in London) and 2026 (Best Conversion or Alteration to an Existing Home, Weech Road NW6), every project is delivered by one team of architects, structural engineers, project managers and builders. Workmanship is guaranteed for 12 months from practical completion, with a 10-year LABC structural warranty.

Nearby areas

Crouch End is part of our North London guide. Nearby areas: Barnet, Finchley, Enfield, Edgware, Hendon, Muswell Hill, Highgate, Stoke Newington.

To book a free consultation call LCCL Construction on 020 8037 7332 or get an instant estimate online. Get an instant estimate or book a free consultation.

One team, one contract, one point of contact — from first sketch to handover.