Basement gyms in Westminster.
Kensington · W8 · Kensington new-build housesCompleted work, photograph
In a Westminster mansion block, a gym is a quiet room within the flat. A whole house can go lower.
A Westminster gym that the block never hears.
- Mansion blocks
- Neighbours above and below
- Policy 50
- One storey for a whole house
- About 76%
- Of Westminster in conservation areas
NU Projects is a design and build company in Fulham SW6, founded in 2010. We handle basement gyms and spa rooms in Westminster SW1P, under one contract. A new basement dig typically runs £500k to £900k. Converting an existing basement runs £180k to £300k. Call 020 7731 6841, and a budget estimate typically follows within seven days.
Most SW1P homes are leasehold flats in mansion blocks. A gym there shares floors with neighbours below. Many leases set rules for hard floors, so we read yours first.
Weights, treadmills and bikes all send vibration into structure. Rubber mounts, a floated slab and lined walls keep it in. Fresh air and cooling run through quiet ducts.
A whole house gives more room to work. Policy 50 allows one storey under the lowest original floor. Under a listed house, the original hierarchy of spaces must stay balanced. Westminster’s Code of Construction Practice governs the build.
Our Kensington houses have a steam room on a lower leisure floor. Nearby in Belgravia, we refurbished an apartment in full. One team designs, prices and builds the gym.
What the council allows in Westminster.
- Council
- City of Westminster. About 76% of the city is conservation area.
- Depth
- Policy 50 allows a single storey under the lowest original floor.
- Listed houses
- A listed building’s original hierarchy of spaces must stay in balance.
- Engineering
- A structural methodology statement from a qualified engineer goes in with it.
- On site
- Westminster’s Code of Construction Practice applies to every basement scheme.
Source: Westminster’s City Plan, January 2026 edition, Policy 50. Read on 16 October 2026. Policies change, so we read them again for your address.
A leisure floor we built, and work nearby.
Kensington·New build
Kensington new-build houses
In Kensington W8: a steam room on a lower leisure floor we built.
See the project
Belgravia·Apartment
Belgravia apartment, full refurbishment
Nearby in Belgravia SW1: an apartment refurbished in full by NU.
See the projectCompleted work, photographs
What a basement gym costs in Westminster.
£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.
A gym inside an existing flat is priced from the survey.
The guide figures are basement project totals. Fees and VAT are extra.
What Westminster owners ask about gyms.
In Westminster
- Every service in Pimlico and Westminster
- Basement construction in Westminster
- Basement swimming pools in Westminster
- Basement golf simulator rooms in Westminster
- Design and build in Westminster
Gyms nearby
- Basement gyms across London
- Basement gyms in Chelsea
- Basement gyms in Kensington
- 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
- Basement gyms in Weybridge
- Basement gyms in Cobham
- Basement gyms in Oxshott
- Basement gyms in Marylebone
- Basement gyms in Highgate
- Basement gyms in Primrose Hill
- Basement gyms in Earl’s Court
- Basement gyms in Pimlico
- Belgravia
- Mayfair
- Fitzrovia and Bloomsbury
Further reading, from the blog
Can I put a gym in a Westminster mansion block flat?
Often, as a quiet room within the flat.
Many leases set rules for hard floors, so we read yours first.
How is gym noise kept from Westminster neighbours below?
A floated floor, rubber mounts and lined walls.
The vibration stays in the room.
Can a whole Westminster house add a basement gym?
Often, within Policy 50’s single storey.
A listed house must keep its hierarchy of spaces.
What rules govern building a Westminster basement gym?
Westminster’s Code of Construction Practice, on every basement scheme.
It covers hours, noise and how the site runs.
Tell us about your home in Westminster.
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