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Unit 3, Palace Court, 250 Finchley Road, London NW3 6DN
⭐ BASEMENT EXCAVATION EXPERTS ⭐

Basement Conversions & Cellar Excavations Across Hampstead, Camden & North London

From shallow cellar conversions to full basement excavations, our structural engineers, waterproofing specialists and fit-out teams deliver luxurious subterranean living spaces including cinema rooms, gyms, wine cellars and self-contained annexes.

Established 2009
Structural Warranty Provider
NHBC Registered

Basement Specialists Trusted Across North London

Every basement project is engineered, waterproofed and finished by our specialist in-house team, ensuring structural integrity and luxurious results.

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Structural Engineering Excellence

Chartered structural engineers design underpinning, contiguous piling, secant walls and reinforced concrete structures tailored to London clay and local geology.

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Comprehensive Waterproofing

Type A, B and C waterproofing systems including cavity drainage, tanking membranes and sump pumps with 10-year insurance-backed guarantees for complete peace of mind.

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Party Wall Expertise

In-house party wall surveyors manage notices, schedules of condition and neighbour agreements, streamlining approvals and maintaining positive relationships.

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Luxury Fit-Out & Finishing

Cinema rooms, home gyms, wine cellars, spas and self-contained annexes finished to the highest standards with premium materials and smart-home integration.

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Building Control & Planning

Full planning applications, building regulations submissions and liaison with local authorities. We handle lawful development certificates and conservation area requirements.

Complete M&E Services

Mechanical and electrical installations including MVHR ventilation, underfloor heating, lighting design, fire detection and full electrical certification.

Recent Basement Transformations

Explore some of our recent basement conversions delivered for discerning homeowners across Hampstead, Hampstead Heath, Belsize Park and North London.

Full Basement Excavation with Cinema
Hampstead, NW3
Wine Cellar & Tasting Room
St John's Wood, NW8
Home Gym & Wellness Suite
Belsize Park, NW3
Self-Contained Guest Annexe
Primrose Hill, NW1
Games Room & Home Office
Hampstead Garden Suburb, NW11
Swimming Pool & Spa Basement
Highgate, N6

The Basement Conversion Journey

A structured approach ensuring your basement project is delivered safely, on time and to the highest standards.

1

Survey & Feasibility

Detailed site investigation including trial pits, soil analysis and structural assessment to determine excavation depth, underpinning requirements and waterproofing strategy.

2

Design & Approvals

Architectural drawings, structural calculations, planning applications, building control submissions and party wall agreements managed seamlessly by our expert team.

3

Excavation & Structure

Careful underpinning, excavation in controlled sequences, reinforced concrete construction and installation of comprehensive waterproofing systems throughout.

4

Fit-Out & Completion

M&E installations, premium finishes, bespoke joinery, smart controls and final inspections, delivering a luxurious living space ready to enjoy.

North London Homeowners Trust Us

Hear from clients who've transformed their homes with our basement conversions.

★★★★★

"They excavated a full basement under our Victorian house creating a stunning cinema room and gym. The engineering was flawless and neighbours were kept fully informed throughout."

Marcus & Emily Chen
Hampstead, NW3
★★★★★

"Converting our damp cellar into a beautiful wine room and guest suite exceeded all expectations. The waterproofing is exceptional and the finish is truly luxurious."

Jonathan Webb
St John's Wood, NW8
★★★★★

"Professional from start to finish. Party wall matters were handled diplomatically and the project was delivered on schedule. We now have an incredible self-contained annexe."

Sarah & David Mitchell
Primrose Hill, NW1

Serving North London's Finest Neighbourhoods

Based in Hampstead, we deliver premium basement conversions across North and North West London.

NW3

Hampstead & Belsize Park

Hampstead Village, Frognal, Belsize Village, Swiss Cottage, Redington Road.

NW1

Camden & Primrose Hill

Primrose Hill, Regent's Park, Camden Square, Chalk Farm, Mornington Crescent.

NW6

West Hampstead & Queens Park

West Hampstead, Queen's Park, South Hampstead, Kilburn, Brondesbury.

NW8

St John's Wood & Maida Vale

Abbey Road, Hamilton Terrace, Maida Vale, Lisson Grove, Little Venice.

NW11

Golders Green & Hampstead Garden Suburb

Temple Fortune, Hampstead Way, North End, Childs Hill, Bigwood Road.

N1

Islington & Angel

Canonbury, Barnsbury, De Beauvoir, Upper Street, Pentonville.

N6

Highgate & Crouch End

Highgate Village, Shepherd's Hill, Crouch End, Archway, Holly Lodge Estate.

N10

Muswell Hill & Alexandra Park

Muswell Hill Broadway, Colney Hatch Lane, Alexandra Palace, Fortis Green.

Basement Conversion FAQs

Clear answers to common questions about basement excavations and conversions.

How much does a basement conversion cost?
Costs vary depending on scope. A cellar conversion (lowering existing floor) typically starts from £1,500-£2,500 per sqm. Full excavations under existing properties range from £3,000-£5,000 per sqm including structure, waterproofing and basic fit-out. We provide detailed fixed quotations after survey.
Do I need planning permission?
Most basement conversions under existing footprints fall under permitted development. However, light wells, external access, listed buildings and conservation areas often require planning approval. We assess your specific situation and manage all applications.
How long does a basement conversion take?
Cellar conversions typically take 8-12 weeks. Full basement excavations range from 4-8 months depending on size, depth and complexity. We provide a detailed programme before works commence.
Will my neighbours be affected?
Basement works are notifiable under the Party Wall Act. We manage all party wall matters professionally, maintaining positive neighbour relations. Modern techniques minimise noise and disruption throughout the project.
How do you keep basements dry?
We install comprehensive waterproofing systems tailored to site conditions, typically combining Type C cavity drainage with sump pumps, backed by insurance-backed warranties. This ensures a permanently dry, habitable space.
What can I use the space for?
Basements are incredibly versatile – popular uses include home cinemas, gyms, wine cellars, home offices, playrooms, guest suites, self-contained annexes, wellness spas and even swimming pools. We design around your lifestyle needs.

Request Your Free Basement Survey

Share a few details and our basement specialists will respond within 24 hours.

Free Feasibility Assessment
Detailed Cost Estimate
No Obligation Quote
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