House Extensions & Loft Conversions in Queen's Park

LCCL Construction is a design and build company based in Finchley N3, working in Queen's Park 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.

Queen's Park and Kensal Rise are Victorian terraces with long gardens — side-return kitchen extensions with rooflights and rear dormers are the core projects, and the streets are close to our Weech Road NW6 award winner.

What it costs in Queen's Park

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).

A recent LCCL project near Queen's Park

Weech Road, Hampstead NW6 — penthouse duplex loft conversion

A top-floor flat turned into a penthouse duplex: the kitchen and living space moved up into the new loft, two new bathrooms, an extra bedroom and views across to the Shard, the London Eye and Parliament. LABC Building Excellence Awards 2026 London Regional Winner — Best Conversion or Alteration to an Existing Home.

See the project

Planning in Queen's Park

Brent and Westminster split the area; the Queen's Park Estate is a conservation area with Article 4 restrictions, elsewhere permitted development usually applies for lofts and single-storey rear extensions.

Conservation areas and Article 4 directions in Queen’s Park

Queen’s Park is two conservation areas under two councils. On the Brent side, the Queen’s Park conservation area (NW6, around Salusbury Road) was designated in 1986, extended in 1995 and again in 2024, when the council adopted a new character appraisal as an SPD (28 May 2024): rows of two- and three-storey Victorian and Edwardian terraces punctuated by small groups of semi-detached villas. An Article 4 direction in the original area removes permitted development for front windows and doors, front painting, front-garden paving, front walls, roof-tile replacement, chimney removal and rear outbuildings; inside the area, alterations to roofs including dormers and hip-to-gable need planning permission, as does a single-storey rear extension beyond 3 m (attached) or 4 m (detached). On the Westminster side, the Queen’s Park Estate (W10) was designated in 1978, extended in 1991 and has had an Article 4 direction since 1992, with 53 Grade II listed houses on Fifth Avenue. The Kilburn and Kensal Rise streets outside both areas usually take lofts and rear extensions on a Lawful Development Certificate.

Extension size rules Brent applies (SPD adopted 16 January 2025)

Brent’s Residential Extensions and Alterations SPD, adopted on 16 January 2025 under the Local Plan 2019–2041, is generous outside conservation areas: single-storey rear extensions can run the full width of the house up to 6 m deep on an attached house and 8 m on a detached one (paras 3.1.2–3.1.3), mirroring the prior-approval route, with the first 3 m or 4 m up to 4 m high and eaves no higher than 3 m, and the total depth no more than half the garden (3.1.4). Two-storey rear extensions are limited to 3 m on an attached house and 4 m on a detached one (3.2.3–3.2.4). A single-storey side extension can go to the boundary (3.3.10) while a two-storey side extension is set back at least 0.5 m at first floor (3.4.2). Rear dormers can take the full width of the original roof, set up at least 0.2 m from the eaves and below the ridge (3.6.2, 3.6.5).

Light to neighbours

The SPD writes the daylight test in for two-storey work: a two-storey rear extension “must not extend beyond the 45 degree line(s) as measured from the middle of the nearest habitable room window(s)” (3.2.5). We apply the same line to single-storey designs so the scheme needs no daylight report.

Fees and timescales

A householder application costs £548 (from April 2026, plus the Planning Portal charge) with an eight-week decision period. Brent’s written householder pre-application advice is £195.60, with a meeting another £195.60, answered within 20 working days. On the Westminster side the written service is £456 including VAT. 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

Brent runs its own building control service. 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: put the rooflights over the island

Rooflights over kitchen islands transform natural light more than any other single design decision. We position them on the plan before the kitchen layout is fixed, not after.

What our clients say

“We have used Lccl in the past for our rear house extension and have come back to instruct Lccl for our loft conversion too to our house in North London. As before we are very happy with the services from Lccl and we highly recommend their design and construction services for both home extension or loft conversion including both design and build services.”

— Mia M, Google Reviews

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

Queen's Park is part of our North West London guide. Nearby areas: Mill Hill, Hampstead, St John's Wood.

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.