Tall basement sitting room with a crystal chandelier under a rooflight.

Basement construction in South West London.

Fulham · SW6 · Fulham basementsCase study

New basements dug beneath SW1 to SW10 houses, and old cellars turned into rooms. One NU team designs, engineers and builds them.

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Going down under the SW postcodes.

SW6
Our studio, minutes from most SW digs
One storey
The most Kensington and Chelsea allows
Two routes
A new dig, or converting a cellar

NU Projects is a design and build company in Fulham SW6, founded in 2010. We handle basement conversion and construction in South West London SW, 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.

Many South West London houses already sit on a vaulted cellar. Others have nothing below the ground floor at all. The first job is finding out which you have.

A conversion lowers and waterproofs the space already there. A new dig underpins the party walls and builds a new box below. Both need an engineer from day one.

Three councils share the SW postcodes. Kensington and Chelsea covers Chelsea, South Kensington and Earl’s Court. Fulham answers to Hammersmith and Fulham, and Belgravia to Westminster.

We have dug and built basements under Fulham and Chelsea houses. Spoil, deliveries and neighbours are planned before the first bay is opened.

What Kensington and Chelsea asks below SW houses.

Council
Royal Borough of Kensington and Chelsea for Chelsea and South Kensington. Hammersmith and Fulham for Fulham.
Policy CD11
Adopted as CL7 in January 2015, kept in the 2024 Local Plan. One storey, under half the garden.
Basements SPD
Adopted April 2016. The storey cannot be split in two later. A pool may earn a little extra depth.
The garden
The garden left over must stay as one area. It is usually the end furthest from the house.
On site
A Construction Traffic Management Plan goes in with the application. The Code of Construction Practice, revised 2019, 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.

Basements we built in South West London.

Basement family room under a light well, with painted joinery and patterned walls.

Fulham·Basements

Fulham basements

A tall basement sitting room under a rooflight in Fulham, SW6.

See the project
The new lower floor during the build: the steel frame up and reinforcement laid for the slab, two builders carrying a board.

Chelsea·Townhouse

Chelsea townhouse, opened up and fitted out

A new lower floor taking shape under a Chelsea townhouse, SW3.

See the project
A small digger at the bottom of the excavation, seen from above. Piles and steel surround it.

Kensington·New build

Kensington new-build houses

The excavation for new houses in Kensington, seen from above.

See the project

Case study

What a basement costs in South West London.

£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.

Both figures are whole project totals for an SW house.

Fees, party wall costs, contingency and VAT sit outside them.

Open the calculatorThe 2026 cost guideBasement costs in fullCan I build it here?

Which SW postcodes does NU dig basements in?

SW1, SW3, SW5, SW6, SW7 and SW10.

That takes in Belgravia, Chelsea, Earl’s Court, Fulham and South Kensington.

Is a Fulham basement judged by the same rules as a Chelsea one?

No. Fulham sits in Hammersmith and Fulham, under its Policy DC11.

Chelsea sits under Kensington and Chelsea’s Policy CD11.

We draw each scheme to its own council.

Can I convert an existing cellar instead of digging new?

Often, yes. Many SW houses have vaults at the front.

Converting them usually costs less than a new dig.

Do my neighbours need to agree to a basement?

They receive party wall notices before work starts.

Each may appoint a surveyor, and an award sets how the work proceeds.

Will we need to move out during the dig?

Usually, for a new basement under the whole house.

A cellar conversion can sometimes run with the family at home.

See it builtNear South West London

See it built.

Finished homes, designed, priced and built by NU.

Living room with tall steel windows and herringbone parquet.

Chelsea · SW3 Townhouse

Chelsea basement and extension

A new basement, a kitchen extension and a full interior renovation.

Case study
Brick and timber houses around a paved courtyard, blue sky.

Fulham · SW6 New build

Fulham, four new-build houses with basements

Four architect designed houses, each with a basement, built as a joint venture.

Case study
Kitchen with a marble waterfall island, steel-framed glazing and a long rooflight.

Fulham · SW6 House

Fulham house, refurbished throughout

A Fulham family house, renewed from the basement to the roof.

Case study

Get a cost estimateRead the case studySee all projects

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