Basement Conversion Services in London
Looking to add more space without moving?
Our basement conversion services in London transform underused cellars and basements into stylish, fully habitable living areas — ideal for home offices, gyms, bedrooms, or rental units.
Whether you’re renovating an existing basement or excavating from scratch, we handle everything: design, structural work, waterproofing, and final fit-out — all tailored to your home and goals.
👉 Book a Consultation
or call 020-805-804-05
Our Basement Conversion Services in London
We offer a complete solution for basement conversion services including:
Why Convert a Basement in London?
Basement conversions are one of the smartest property upgrades in London. In fact, they’re often the only way to expand in areas with limited garden or loft space.
Key benefits include:
-
Add up to 30% more floor space
-
Increase your home’s value by £100,000+
-
Avoid planning restrictions common to lofts/extensions
-
Create a private space for guests, teenagers, or tenants
-
Build a home office, gym, cinema room or extra bathroom
Moreover, we handle all approvals and engineering — making the process smooth from start to finish.
What’s Included in a Basement Conversion
We provide a fully managed service for new and existing basement spaces.
Site Assessment & Planning
From £1,500+
We start with a detailed inspection, structural survey, and architectural planning — including floorplans, head height analysis, and soil investigation if needed.
Excavation & Underpinning
From £20,000+
If you need a deeper or new basement, we excavate and underpin the existing foundations using proven methods.
We ensure structural safety and legal compliance throughout.
Waterproofing & Tanking
From £7,000+
We install full waterproofing systems (membranes, drainage, sump pumps) to keep your basement dry and safe — guaranteed.
Structural Work & Construction
From £10,000+
We build walls, raise ceilings, install RSJs, reinforce floors, and ensure access via stairs, fire escape routes, and ventilation systems.
Fit-Out: Electrics, Plumbing & Finishes
From £15,000+
We fit bathrooms, lighting, insulation, flooring, and decoration — turning your basement into a clean, bright, and welcoming living space.
Basement Conversion Costs in London
Prices vary based on whether the basement already exists or requires excavation.
-
Existing basement conversion: from £45,000
-
Excavation + full conversion: £70,000–£120,000+
-
Luxury fit-outs or multiple rooms: from £100,000+
📍 Areas We Cover in London
We’ve completed basement conversions in:
-
North London – Camden, Islington, Hampstead
-
East London – Bow, Bethnal Green, Hackney
-
South London – Dulwich, Clapham, Wimbledon
-
West London – Ealing, Notting Hill, Kensington
Because we work locally, we understand borough-specific planning rules, listed building restrictions, and party wall agreements.
👉 Book a Consultation
or call 020-805-804-05
Basement Conversion Ideas
Here are some of the most popular uses for London basements:
-
💼 Home office with natural lighting
-
🛏️ Guest bedroom with en-suite
-
🎬 Media/cinema room
-
🏋️ Gym with rubber flooring and mirrors
-
🛁 Utility + shower room
-
🧒 Children’s playroom or teen retreat
-
💼 Self-contained rental unit (annex)
We’ll help design and build the perfect space to fit your vision.
Who We Work With
We support:
-
Homeowners needing more room but limited by loft/extension options
-
Landlords & investors creating rentable lower-ground flats
-
Developers adding value to multi-unit or period properties
-
Families designing custom lower levels for growing needs
Looking for above-ground options instead? Explore our Loft Conversion Services or House Extensions in London
FAQs – Basement Conversions in London
-
Do I need planning permission for a basement conversion?
Not always. Internal basement conversions often fall under permitted development. However, excavation, external access, or changes to the façade may require permission. We’ll handle all submissions.
-
How long does a basement conversion take?
-
Is waterproofing guaranteed?
-
Can I convert a cellar with low ceiling height?
Book a Free Basement Conversion Consultation
Let’s create the extra space you need — below your feet.
We offer free consultations, feasibility assessments, and fixed-price quotes for all basement conversions in London.
👉 View our Full Home Renovation Services