BasementsHolland Park W11 · W14
Basement construction in Holland Park.
Basements under Holland Park villas, within one storey. Trees, drainage and listed fabric are designed in from the start.
Under a Holland Park villa, one storey.
NU Projects is a design and build company in Fulham SW6, founded in 2010. We handle basement conversion and construction in Holland Park W11, 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.
Holland Park is villas on wide plots, many semi-detached, with mature gardens and trees.
A wide garden leaves room for a generous single storey. Half of it must stay unexcavated, in one piece.
The borough resists any dig under a listed building. Some villas here are listed.
The trees matter too. A basement that threatens a valued tree is resisted.
So we plan the structure, the drainage and the tree protection as one design.
What the council allows.
- Council
- Royal Borough of Kensington and Chelsea, under its Local Plan adopted in July 2024.
- Extent
- Policy CD11. One storey, under no more than half the garden, left in one area.
- Trees
- No loss or long term threat to valued trees. A full tree survey goes in.
- Listed villas
- No excavation under a listed building, including its vaults.
- Soil and drainage
- One metre of soil over any basement under a garden. Sustainable drainage is required.
- Flood risk
- Every basement in the borough needs a flood risk assessment. The borough names a Holland Park critical drainage area.
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.
Built below ground in the borough.
Kensington·New build
Kensington new-build houses
A lower leisure floor in the same borough, with steam room and walnut joinery.
See the project
Chelsea·Townhouse
Chelsea basement and extension
A new Chelsea basement, fitted out by the team that dug it.
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.
A villa basement is often wider than a terrace’s, so the total rises.
The band is per square foot, construction only. The guide figures are project totals.
Fees, party wall costs, contingency and VAT sit outside both.
Open the calculatorThe 2026 cost guideBasement costs in full
Basements in Holland Park, answered.
How big can a basement be under a Holland Park villa?
One storey, under no more than half the garden.
The half you keep must stay in one piece, usually at the far end.
On a wide plot that still leaves room for a large single floor.
Can I dig a basement under a listed Holland Park house?
Not under the house itself. The borough resists digging under any listed building.
A basement in the garden may be possible, built structurally independent of the house.
The link to the house must be discreet.
Will the trees in my Holland Park garden stop a basement?
They shape it more than stop it.
The borough resists any loss or long term threat to valued trees.
A full tree survey and a protection plan go in with the application.
Does a Holland Park basement need a flood risk assessment?
Yes. Kensington and Chelsea asks for one with every basement.
It also needs sustainable drainage, and a pumped device against sewer flooding.
What does a Holland Park basement cost?
Per square foot, our basement band runs £450 to £500, construction only.
Digging new runs from £500k to £900k and more, as a project total.
A wide villa tends toward the top of that range.
Related pages.
Basements nearby
- Basement conversion across London
- Basement conversion in Fulham
- Basement conversion in Chelsea
- Basement conversion in Kensington
- Basement conversion in St John’s Wood
- Basement conversion in South Kensington
- Basement conversion in Knightsbridge
- Basement conversion in Belgravia
- Kensington
- South Kensington
- Chelsea
- Chiswick
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