Lower-ground kitchen with a dark wood breakfast counter, internal stairs and doors to a garden-access patio
| 4.8 42+ Reviews
Considerate Construction Scheme

Basement Conversion in Kensington

A basement conversion in Kensington requires more than vision; it demands structural precision and expertise.

Proficiency Design & Build brings over a decade of construction experience and award-winning basement designs to this affluent Royal Borough of Kensington and Chelsea conservation area.

Convert With Us
Bright basement living room with wide steps at the front, a straight back-left staircase and right-hand lightwell glazing

Rated 4.9/5 on

Fantastic builders who really care about the quality of finish.

Portrait of Oliver Meek

Oliver Meek ( Director At Rio Cinema )

Why Choose Proficiency

Area
Specialists

With 14+ years of experience, our basement company understands Kensington's architectural heritage, local building regulations, and planning permission process, delivering compliant, high-quality builds across some of West London's most prestigious locations.

Expert Project Management

Every basement project is expertly led by a dedicated project manager who oversees timelines and tradesmen from start to finish. From initial design and basement excavation to final handover, we strive to deliver complete customer satisfaction.

Bespoke
Design

Using high-quality building materials and innovative design techniques, our interior design and structural engineering teams enhance your property's potential with grand basement conversions that stand the test of time.

The Proficiency Advantage

SW7 Basement Conversion Specialists

As trusted basement conversion contractors serving South West London and its surrounding areas, we help homeowners transform outdated basement spaces into functional areas that reflect their modern lifestyle and routines.

We discreetly handle all planning applications, party wall agreement matters, building regulations, and listed building submissions with the Kensington and Chelsea Council, ensuring discretion and compliance at every turn.

Whether you envision an elegant home cinema room, a stylish home office, a private swimming pool, or a games room for the children, our basement conversion builders design beautiful, usable spaces tailored to your lifestyle and vision.

Start Your Conversion

Basement Conversion Process

Free Consultation

Our experienced team assesses feasibility and handles planning applications to establish the potential of your new basement conversion on your behalf.

Structural Planning & Design

Expert structural engineers and architects provide detailed 3D-rendered drawings and submit them to the Kensington Council for all necessary approvals.

Excavation & Groundworks

All basement excavation and structural work is completed to the highest safety and engineering standards in UK construction.

Waterproofing & Drainage

We install industry-approved waterproofing systems to prevent dampness and water ingress for all Kensington basement conversions.

Fit-Out & Finishing

High-end materials, bespoke joinery, and refined detailing bring your new basement space to life.

Our Building Company

Proficiency Design & Build is a trusted home improvement company, specialising in expert basement conversions across Greater and Central London.

  • Federation of Master Builders - Membership assures quality work, financial stability, and compliance with basement-specific standards.
  • Fully Insured - Comprehensive coverage, including Public Liability, Professional Indemnity, and Contractors All Risk. We are also NICEIC and Gas Safe approved.
  • Considerate Contractor Scheme - Commitment to ensuring worker wellbeing, community relations, and reducing environmental impact on every home extension project.
    • Contact Proficiency

Our Building Projects

Kitchen interior in The Avenue completed build with veined marble worktops and black-and-brass pendants
The Avenue, Queen's Park Side Return House Extension View Project
Kitchen and dining space in the Conewood Street build with a pale pink island and brass-handled cabinetry
Conewood Street, Highbury Side Kitchen Extension View Project
Light-filled kitchen in the Twickenham completed build with a white-topped island and timber breakfast bar
Cambridge Road, Twickenham Open Plan Kitchen Extension View Project
Kitchen interior in the Westbere Road completed project with a pale island worktop and herringbone timber flooring
Wesbere Road, West Hampstead Kitchen Renovation View Project

Luxe Basement Conversion Services
Refitted basement room with a sofa, armchair and TV shelving, a kitchenette on the left and curved carpeted stairs to the right

Refurb

Upgrade old basements into brighter, modern spaces with improved layout, lighting, insulation, and premium finishes.

Refurb Your Basement
Basement lounge with a small hopper window, white open-riser stairs and dark seating on a patterned rug

Conversion

Complete conversions of Kensington basements, including excavation, groundworks, damp-proofing, and interior fit-out.

Basement foyer leading to two rooms and a wine cellar with timber shelving beside a curved staircase

Cellar

Bespoke basement conversions for wine cellars, tasting rooms, and entertainment areas.

Building a room

Contact Local Basement Conversion Experts

Contact Proficiency Design & Build for all your basement conversions in Kensington.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.