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LCCL Construction – design and build company, London N3
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Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.

Services

Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.

Services

Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.

Services

Loft conversions, house extensions, renovations, basements and new builds across London and Hertfordshire.

Services

Call 020 8037 7332 or get an instant estimate online.

New Cavendish Street, Marylebone W1W — LCCL Construction project

New Cavendish Street, Marylebone W1W

Mansard loft · Renovation — Georgian terrace (c.1775) — Completed 2018

A mansard roof extension and reconfiguration of a Georgian terrace in Marylebone: open-plan kitchen, two bedrooms and a roof terrace, taken through Westminster planning.

Project facts

  • HouseGeorgian terrace (c.1775)
  • Added+2,000 sq ft
  • On site35 weeks
  • Completed2018
  • PlanningFull planning + listed building consent (Westminster)
  • Contract value£250,000 – £350,000 inc. VAT

Project type: Mansard loft · Renovation · Area: Marylebone W1W

What we did

  • Mansard roof extension
  • Open-plan kitchen
  • Two bedrooms
  • Roof terrace
  • Westminster planning and conservation consent

Specification

New Kitchen · Lusso Stone · Italian Marble Floors

Design and build inclusive: architecture, structural engineering, planning, party wall, construction, project management and LABC sign-off under one contract.

How design and build works

Anderson's note

A mansard in Westminster is a planning project first and a build second — the roof form, the slate and the dormer proportions all have to match the terrace. Thirty-five weeks on site reflects working inside a Georgian structure.

Anderson, founder — LCCL Construction, Finchley N3

The client's view

“Professional reliable and organised loft conversion company would highly recommend”

Verified client · EmbedSocial reviews

As LABC Building Excellence Award Winners 2024 for Best Residential Extension in London, and 2026 London Regional Winners for Best Conversion or Alteration, every project runs under one contract with a 12-month workmanship guarantee and a 10-year LABC structural warranty.

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

More projects like this

Great Portland Street, Fitzrovia W1 — LCCL Construction project

Great Portland Street, Fitzrovia W1

Renovation · 2025 · £150,000 – £200,000 inc. VAT

Bohun Grove, East Barnet EN4

Bohun Grove, East Barnet EN4

Rear extension + Hip-to-gable loft · 2023 · £395,000 – £475,000 inc. VAT

Weech Road, Hampstead NW6

Weech Road, Hampstead NW6

Loft conversion + Renovation · 2025 · £250,000 – £300,000 inc. VAT

Holmwood Gardens, Finchley N3

Holmwood Gardens, Finchley N3

Rear extension + Kitchen extension · 2022 · £130,000 – £180,000 inc. VAT

Planning something similar?

Get an instant estimate for your postcode, or book a free 30-minute call with our team. Call 020 8037 7332, Monday to Saturday 08:00–18:00.

What clients say

Verified reviews, quoted exactly

average rating is 5 out of 5
“LCCL Construction was the right company to help with my loft conversion. I heard of other people's challenging experiences with building works so I was very careful which company I chose. LCCL Constructions was professional, trustworthy and worked to the…”

KashImaging · Trustpilot

average rating is 5 out of 5
“Contracted lccl construction to design and build hip to gable loft conversion, after much research I found Lccl construction to be the most efficient and reliable company to deal with, the initial design phases started immediately their architects attended…”

Behar · Trustpilot

average rating is 5 out of 5
“2ND project with LCCL construction wraparound house extension. Completed full design and build process to our home in Finchley north London. Previously they have design and build our loft conversion 4 years on and still it is in excellent condition.…”

Anthony · Trustpilot

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