Basement Conversion in London
Home » Refurbishment »
Unlock the Potential of Your Basement
At Bigness Group, we specialise in basement conversions across London, turning unused or underutilised spaces into stylish, functional rooms. Whether you want a home office, gym, bedroom, entertainment space, or wine cellar, our expert team delivers safe, compliant, and high-quality basement transformations.
Why Consider a Basement Conversion?
-
Maximise space without moving house
-
Increase property value by adding usable square footage
-
Create bespoke rooms tailored to your lifestyle
-
Modern, safe, and compliant with London Building Regulations
Our Basement Conversion Services
Structural & Waterproofing Works
We carry out underpinning, tanking, and damp-proofing to ensure your basement is structurally sound and fully waterproof.
Full Design & Planning
Our architects and designers create layouts that maximise light, space, and practicality — with options for natural light wells and ventilation.
Fit-Out & Installation
From flooring and heating systems to lighting, plumbing, and bespoke joinery, we handle every aspect of the fit-out with precision.
Specialist Basements
Wine cellars, luxury gyms, cinemas, and bespoke spaces built to your specification with premium finishes.
Why Choose Bigness?
-
Experienced London specialists with borough-level planning knowledge
-
End-to-end service: Design, planning, permissions, and construction
-
Compliance first: Structural integrity, fire safety, waterproofing, and ventilation
-
Transparent pricing with no hidden costs
-
On-time delivery with minimal disruption to your home life
Frequently Asked Questions
Do I need planning permission for a basement conversion?
Many conversions fall under permitted development, but new builds or major alterations may require planning. We’ll advise and handle all approvals.
How long does a basement conversion take?
Typically 3–6 months, depending on size, structure, and finishes.
Is waterproofing included?
Yes — we use industry-approved tanking and damp-proofing systems to ensure your basement remains dry and safe.
Will a basement conversion add value to my home?
Yes, a well-executed basement conversion can significantly increase property value, especially in London where space is at a premium.
Our Latest Basement Conversion Projects in London
Take a look at some of our recent basement conversions across London. From transforming dark, unused cellars into bright family living spaces, to creating luxury gyms, wine cellars, and home cinemas, these projects highlight our ability to combine structural expertise with creative design. Every basement we deliver is safe, stylish, and built to last — adding both value and functionality to London homes.
Basement Conversion Company in London by Borough
At Bigness, we provide professional property refurbishment services across every London borough. Whether you’re renovating a flat, modernising a family home, or upgrading a commercial property, our expert team is here to deliver high-quality results. Explore the areas we cover below to find refurbishment services near you.
Barking and Dagenham / Barnet / Bexley / Brent / Bromley / Camden / Croydon / Ealing / Enfield / Greenwich / Hackney / Hammersmith and Fulham / Haringey / Harrow / Havering / Hillingdon / Hounslow / Islington / Kensington and Chelsea / Kingston upon Thames / Lambeth / Lewisham / Merton / Newham / Redbridge / Richmond upon Thames / Southwark / Sutton / Tower Hamlets / Waltham Forest / Wandsworth / Westminster