Basement gyms in Kensington.
Chelsea · SW3 · Chelsea townhouse, opened up and fitted outCompleted work, photograph
A gym under a Kensington house, built so the flat above hears nothing. One team designs, prices and builds it.
What a Kensington gym has to solve.
- W8
- Stucco terraces and brick villas
- One storey
- Policy CD11, under half the garden
- Sound first
- The floor is separated from the structure
NU Projects is a design and build company in Fulham SW6, founded in 2010. We handle basement gyms and spa rooms in Kensington W8, under one contract. A basement runs £450 to £780 a sq ft, construction only. Call 020 7731 6841, and a budget estimate typically follows within seven days.
Kensington runs from stucco terraces to brick villas on the hill. Many houses are split into flats, with a garden flat at the bottom. A gym here sits close to other people’s ceilings. Sound is the first thing we plan.
The borough sets one storey under half the garden. Houses that back onto communal gardens often own very little of their own. So the gym may take most of the storey that is allowed. Planning is needed, and the gym is drawn into the application.
Dropped weights carry through concrete. We lay the gym floor on isolating pads, apart from the structure. The ceiling is a second layer, hung on springs. Cooling comes from quiet ducts, never a loud wall unit.
We dug two new houses in Kensington, three floors down. Their lower floor holds a steam room in walnut joinery. The same team that dug the site fitted that floor.
What the council allows in Kensington.
- Council
- Royal Borough of Kensington and Chelsea. It rules on every gym below a Kensington house.
- Floor area
- CD11 limits the dig, so racks, cardio and stretching share one storey.
- No second floor
- The storey cannot be split in two later. A mezzanine for a studio is not an option.
- Consent
- Planning is needed for any gym. Dust, noise and lorries are covered in a traffic plan.
- Sound
- The gym floor sits on isolating pads, apart from the structure.
Source: Kensington and Chelsea’s Local Plan 2024, Policies CD4, CD5, CD11 and CD13. Read on 3 October 2026. Policies change, so we read them again for your address.
Lower floors in the borough.
Chelsea·Townhouse
Chelsea townhouse, opened up and fitted out
A basement gym in a Chelsea townhouse, in the same borough.
See the project
Kensington·New build
Kensington new-build houses
A steam room below two new houses we built in Kensington.
See the projectCompleted work, photographs
What a basement gym costs in Kensington.
£450 to £780a sq ft, construction only. Our basement band.
£180k to £300kConverting an existing basement. A project total, from our 2026 cost guide.
£500k to £900k+Digging a new basement. A project total, from our 2026 cost guide.
These are two kinds of figure. The band is a rate per square foot, construction only.
The cost guide figures are whole project totals.
Fees, party wall costs, contingency and VAT sit outside them.
What Kensington owners ask about gyms.
In Kensington
- Every service in Kensington
- Basement construction in Kensington
- House extensions in Kensington
- Luxury refurbishment in Kensington
- Interior design in Kensington
- Party wall surveying in Kensington
- Architects in Kensington
- Basement swimming pools in Kensington
- Basement cinema rooms in Kensington
- Basement golf simulator rooms in Kensington
Gyms nearby
- Basement gyms across London
- Basement gyms in Chelsea
- Basement gyms in South Kensington
- Basement gyms in Holland Park
- Basement gyms in Notting Hill
- Basement gyms in Knightsbridge
- Basement gyms in Belgravia
- Basement gyms in Mayfair
- Basement gyms in St John’s Wood
- Basement gyms in Hampstead
- Basement gyms in Fulham
- Notting Hill and Holland Park
- South Kensington
- Chelsea
Further reading, from the journal
Who would hear a basement gym in Kensington, the flat above or next door?
Neither, if the floor is separated properly.
Pads under the slab stop sound entering the structure.
A sprung ceiling handles what remains.
Can a Kensington basement gym sit under a garden flat?
It can, with the freeholder’s consent.
The room is acoustically separate from the flat above.
We agree the method with the owners first.
Is a basement gym allowed in Kensington?
Yes, as one storey under half the garden.
Every basement here needs planning.
We prepare the application, the structure and the traffic plan together.
How long does a Kensington basement gym take to build?
The dig and structure take the longest.
The fit-out follows once the room is dry.
We give you a programme when we price the house.
Can we add a steam room to a Kensington basement gym?
Yes.
The steam room needs a tiled, sealed shell and its own extract.
It sits beside the gym, never inside it.
Tell us about your home in Kensington.
Your name and one way to reply are enough. It goes straight to the studio.
- Already have an architect or designer? We build to their design. Working with your designer
- An NDA on request, and your home is never published without your consent. How we work in confidence