BasementsSouth Kensington SW7
Basement construction in South Kensington.
Our two South Kensington houses went three floors down. Today CL7 allows one storey, and we design it to count.
Three floors down, then the rules changed.
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 basement runs £450 to £500 a sq ft, construction only. 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. CL7 now limits a new basement to one storey. So we design that storey to work hard.
What the council allows.
- Council
- Royal Borough of Kensington and Chelsea.
- Policy CL7
- Adopted January 2015. One storey only, under no more than half the garden.
- Pools
- The 2016 Basements SPD allows a little extra depth for a swimming pool.
- Planning
- Since April 2016, every basement here needs planning permission.
- On site
- A Construction Traffic Management Plan goes in with the application. The Code of Construction Practice governs the site.
Source: Policy CL7, the 2016 Basements SPD and the Article 4 direction. Read on 6 September 2026. Policies change, so we read them again for your address.
Dug and built in South Kensington.
South Kensington·New build
South Kensington new-build houses
The lower floors under construction, with concrete piles and steel props.
See the project
South Kensington·New build
South Kensington new-build houses
The finished lower leisure floor, with a steam room and walnut joinery.
See the projectCompleted work, photographs
What it costs.
£450 to £500a 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.
The band is a rate per square foot, construction only.
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
Basements in South Kensington, answered.
Could I build a triple basement in South Kensington today?
No. CL7 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 South 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?
Our basement band is £450 to £500 a sq ft, construction only.
A new dig runs £500k to £900k and more, as a project total.
Related pages.
In South Kensington
From the journal358 notes, free to read
South Kensington, written up.
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Basement waterproofing and pumps in London
What keeps a London basement dry. Waterproofing as one coordinated design, when pumps are needed, alarms, servicing and costs.
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The real cost of a London basement: what homeowners need to know before starting
What a London basement actually costs in 2026. Shell against fit out, what sits outside the build rate, fees, contingency and the hidden risks.
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Basement extensions in London: what homeowners need to know before they dig
Everything London homeowners need to know about basement extensions. Planning, costs, party walls, and construction advice from NU Projects.
Basements, South Kensington
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