We design and build high-performance basements across London and the South East—from retro-fit conversions to new-build basements, swimming pools, gyms, cinema rooms and wine cellars. Our work combines BS 8102 waterproofing led by a CSSW specialist, BS 5975 temporary works, and borough-ready BIA/CTMP/CMP submissions to deliver beautiful, dry spaces that stand the test of time view our basement projects

Building Down to Unlock Space in London

In London, where space is scarce, more homeowners and self-builders expand underground. A well-designed basement maximises footprint without changing the street facade, but success demands specialists—BS 8102 waterproofing, BS 5975 temporary works, party wall expertise, BIAs and borough approvals.

Basement Structures partners with developers, architects and homeowners to make the toughest phase predictable—delivering safe excavation, engineered structures and watertight results on time and on budget. We handle feasibility, BIA/CTMP submissions, waterproofing design and premium fit-out, so your London basement is beautiful, dry and built to last.

Our Professional Services
London basement construction and excavation by specialist contractors – engineered waterproof structures built to BS 8102 standards, maximising space safely and beautifully underground.
Darren Wilks, Director of Basement Structures, leading a London basement design and build team with over 30 years of experience in structural engineering and waterproofing

Who We Are — A Reputation Built on Experience

Led by Director Darren Wilks, Basement Structures is a dedicated basement design-and-build contractor with 30+ years delivering complex projects across London’s tight streets, conservation areas and listed buildings. After running two successful basement companies for over two decades and consulting on large-scale schemes for major contractors, Darren founded Basement Structures to solve two gaps he saw repeatedly: specialist new-build basement construction and a reliable, accountable service that creates robust underground structures ready for bespoke fit-out.

Today, our in-house team coordinates structural engineering, BS 8102 waterproofing, BS 5975 temporary works and premium finishes under one roof—streamlining risk, programme and cost for homeowners, architects and main contractors.

Find Darren on Linkedin

Why Hire Basement Structures — London Basement Specialists

Basements are all we do. Our London-first methods, heritage experience and live site controls minimise risk, disruption and cost for basement conversion and new-build basement projects.

  • 30+ years building basements in London
  • In-house delivery with named leads for design, waterproofing & temporary works
  • Seamless coordination with homeowners, architects & main contractors
  • You're in safe hands, we are fully insured with £1 million professional indemnity and £10 million public liability cover
  • Proven sequencing for mews plots & listed buildings
  • Neighbour management & considerate construction
  • Transparent programme and cost control
Basement Structures team delivering specialist London basement conversions and new-build basements with over 30 years of experience, in-house design, waterproofing, and temporary works expertise

BS 8102 waterproofing by CSSW designers

We design for a Grade 3 internal environment, typically combining Type B watertight concrete with a maintainable Type C cavity drain, dual pumps and alarms—signed off by a CSSW waterproofing specialist .

  • Penetration & joint detailing included
  • Serviceable drainage routes with aftercare plan
  • Clear warranty pathway and acceptance with major providers

Engineered excavation & temporary works (BS 5975)

Safety and structural performance are managed under BS 5975 with an appointed Temporary Works Coordinator, design briefs and check categories, permits-to-load and hold points, plus monitoring for movement, noise and vibration.

  • Underpinning, propping & façade retention
  • Trigger/action level monitoring
  • Methods aligned with best-practice guidance

Planning, BIAs & logistics handled

We prepare borough-ready Basement Impact Assessments and CTMP/CMP/CLP submissions, coordinate traffic routing and stakeholder communications, and support Section 61 where required across Camden, RBKC, Westminster and wider London.

  • Neighbour liaison & considerate sites
  • Faster, clearer approvals pathway
  • End-to-end compliance support

Assurance & compliance

  • BS 8102 waterproofing led by a CSSW specialist
  • BS 5975 temporary works with appointed TWC/TWS
  • Construction management aligned with borough CoCPs
  • Considerate Constructors approach to neighbours
  • BIA, CTMP/CMP/CLP and Section 61 support

Insurance & Guarantees

We maintain comprehensive construction insurance coverage for all our projects, including £1 million professional indemnity and £10 million public and employer’s liability insurance. This ensures full protection and peace of mind throughout every stage of your basement project.

  • Full PI, PL, and EL insurance coverage
  • Policy details available upon request

What we deliver

  • Basement design & planning support
  • Retro-fit conversions & under-garden basements
  • New-build basements for prime residential
  • Basement waterproofing & drainage (BS 8102)
  • Swimming pools, spas, gyms, cinemas & wine cellars
  • Underpinning, excavation & temporary works (BS 5975)
Start your project View basement case studies
Luxury London basement with pool, gym, cinema room and wine cellar built by Basement Structures with integrated waterproofing, structure and ventilation systems

What we build

From discreet under-house extensions to expansive under-garden spaces, we deliver luxury basements tailored to your lifestyle—including pools, spas, gyms, cinema rooms, wine cellars and staff/guest suites. Our integrated approach brings structure, MEP, ventilation and acoustics together for quiet, comfortable spaces that feel natural to live in.

Our process

Step 1

Feasibility & budget bands — space planning, head-height studies and realistic cost ranges.

Step 2

Design & approvals — waterproofing (BS 8102), structure & temporary works (BS 5975), BIA/CTMP, surveys & party wall.

Step 3

Excavation & structure — monitored sequencing with neighbour care and quality hold points.

Step 4

Waterproofing, fit-out & handover — combined systems, commissioning and aftercare.

View our videos
questions/answers

About Basement Structures — FAQs

Basements are our specialty. We combine BS 8102 waterproofing led by a CSSW designer, BS 5975 temporary works, borough-ready BIAs/CTMPs, considerate neighbour management and genuine long-term guarantees—managed by one accountable team.

Yes. We prepare Basement Impact Assessments (BIA) and CTMP/CMP/CLP submissions for London boroughs, coordinate logistics and traffic, support Section 61 where required, and operate considerate sites with clear, proactive communication to neighbours.

We design for a Grade 3 internal environment to BS 8102, typically combining Type B watertight concrete with a maintainable Type C cavity drain system, dual pumps and monitoring. All details—joints, penetrations and drainage—are signed off by a qualified CSSW waterproofing designer and supported by aftercare.

Yes. We plan sequencing, temporary works and monitoring for heritage and mews settings, liaise with conservation officers, and run neighbour-friendly sites with robust logistics, noise/dust management and clear reporting.

We carry the appropriate construction insurances (including £1m design professional indemnity) and £10m public liability cover.

Start Your Basement Construction in London

- 30+ years’ experience building basements

- We are fully insured: £1M PI + £10M liability

Ready to add valuable living space with a new-build or retro-fit basement? Our London team handles feasibility, planning, excavation, BS 8102 waterproofing and luxury fit-out — end to end.

Request a Consultation Call 0784 135 2195

Where we work

We deliver basements across London, including Camden, Kensington & Chelsea, Westminster, Hammersmith & Fulham, Wandsworth, Richmond, Islington, and surrounding boroughs.

Start your basement project