Basement conversion and construction in South Kensington.
Kensington · W8 · Kensington new-build housesCompleted work, photograph
Our two houses next door, in Kensington W8, went three floors down. Today CD11 allows one storey, and we design it to count.
Three floors down, then the rules changed.
- Three floors
- Down, under our two new houses in W8
- CD11, 2024
- One storey for new basements now
- SW7
- Stucco terraces, squares and mews
NU Projects is a design and build company in Fulham SW6, founded in 2010. We handle basement conversion and construction in South Kensington SW7, 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.
Nick found the site, an old block of flats. He worked out it could hold two family houses of 6,500 sq ft each.
Both went three floors down, with a pool two floors below the street. Planning came through, then the borough paused new basements for a year.
Every drawing and finish was settled in that year, before the dig began. Then one team dug, built and fitted both houses.
That depth is no longer allowed. Policy CD11 now limits a new basement to one storey. So we design that storey to work hard.
What the council allows in South Kensington.
- Council
- Royal Borough of Kensington and Chelsea.
- Policy CD11
- Adopted as CL7 in January 2015, kept in the 2024 Local Plan. One storey, under half the garden.
- Pools
- The 2016 Basements SPD allows a little extra depth for a swimming pool.
- Neighbours
- Considerate Constructors Scheme membership is set by planning condition.
- On site
- A Construction Traffic Management Plan goes in with the application. The Code of Construction Practice governs the site.
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.
Dug and built in Kensington W8.
Kensington·New build
Kensington new-build houses
The finished lower leisure floor next door in Kensington W8, with a steam room.
See the project
Kensington·New build
Kensington new-build houses
The same two houses, with a pool two floors below the street.
See the projectCompleted work, photographs
What a basement costs in South Kensington.
£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.
The cost guide figures are project totals. Fees, party wall costs, contingency and VAT sit outside.
A pool adds depth, plant and waterproofing, so it adds cost.
Open the calculatorThe 2026 cost guideBasement costs in full
What South Kensington owners ask about basements.
In South Kensington
- Every service in South Kensington
- Interior design in South Kensington
- Luxury refurbishment in South Kensington
- Basement swimming pools in South Kensington
- Basement gyms in South Kensington
- Basement cinema rooms in South Kensington
- Basement golf simulator rooms in South Kensington
- Luxury painting and decorating in South Kensington
Basements nearby
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- Kensington
- Chelsea
- Knightsbridge
Further reading, from the journal
Could I build a triple basement in South Kensington today?
No. The borough has limited new basements to one storey since 2015.
Our two houses were consented before the borough paused new basements.
Can a South Kensington basement include a pool?
Sometimes. The borough’s 2016 guidance allows a little extra depth for one.
It still has to sit within one storey and half the garden.
How long did the Kensington houses take?
Planning came through, then the borough paused new basements for a year.
We used that year to settle every drawing and finish before the dig.
What does a South Kensington basement cost?
A new dig runs £500k to £900k and more, as a project total.
Tell us about your home in South 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