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

“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
“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
“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








