Basement contractors in London. We design, engineer and build basements under one contract. Basement cost in London, the 2026 figures.
Basement conversions in Fulham, Chelsea and Kensington.
Most collectors start with the cars. We start with the ground under them.
A basement car gallery is a basement first. It needs the same care as any London dig. Then it needs a way in for the cars, and a room worth visiting.
This is how we plan one, from the first visit to the handover. Our sister studio, BELOW, works only on car galleries, and runs the same steps.
The first visit is about the plot, not the plan
We walk the house, the garden and the street. We look at the drive, the trees and the neighbours.
A car needs a route down. That route is a lift, a ramp or both. In a terrace, a lift is often the only choice. On a wider plot, a ramp may fit.
We also ask about the collection. How many cars, which eras, and how often they move. A car used each weekend needs a quicker route than one stored for winter.
Feasibility comes before any drawing
Feasibility tells you if the gallery can be built, and roughly what it involves. It starts with surveys.
A ground investigation shows the soil and the water table. A tree survey shows which roots must be protected. A utilities search finds the pipes and cables under the garden.
From those facts our engineers choose a way to hold the ground back. Our quantity surveyor then prices the work, line by line, before you commit.
Each borough sets its own basement rules
London councils write their own basement policies. Kensington and Chelsea limits how far a basement may extend under a garden. Westminster asks for soil over a basement roof, so planting can survive. Camden asks for evidence on groundwater and stability.
Our planning consultants read the policy for your street before the design is drawn.
Conservation areas and listed houses add another layer. A pavilion or lift head must sit quietly in its setting. The less it shows above ground, the easier the case.
Neighbours are part of the programme
A dig near a neighbour usually needs notice under the Party Wall Act. We serve the notices early, so awards are agreed before work starts. Our party wall page explains what that involves.
Councils also ask for a construction management plan. It covers lorries, working hours, noise and dust. On a narrow street, it decides the size of every rig.
Design starts with the lift and the second way out
The lift sets the shape of the gallery. Its size, travel and pit come from the maker. They decide the room around it.
A gallery also needs a second way out for people. Fire safety rules expect it. We plan it with the first sketch, not the last.
Waterproofing is designed in layers, so one failure does not reach the cars. Our basement waterproofing page explains the standard we build to.
Air, fire and security are engineered, not added
A sealed room below ground needs mechanical ventilation. Cars give off fumes, and stored cars need steady humidity.
Detection, fire separation and a clear escape are part of building control. Insurers often ask for more, such as a monitored alarm.
Security is layered. Access, alarms and cameras connect to one system on your phone.
The build follows the same order every time
First come the enabling works and the protection of trees and neighbours. Then the walls that hold the ground, the dig and the base.
Next the structure is sealed and the lift pit formed. Services follow, then the lift, then the finishes.
One team runs it all, from first drawing to handover. That is how design and build keeps a complex dig on programme.
The room inside is drawn around the cars
Each car needs a bay wide enough to open both doors. The aisle must let a car turn in and out without a shuffle.
Lengths vary by era. A pre-war tourer and a modern grand tourer need very different bays. We draw the bays to your cars, not to a standard.
Many clients add a wash bay, a small workshop or a lounge. Each one adds area, so we agree the list at feasibility.
A turntable can save space where a car cannot reverse out. It sits flush with the floor, and turns the car in its own length.
The programme depends on ground and planning
No two galleries take the same time. Planning, party wall awards and the ground set most of the programme.
Some surveys can only run in certain seasons. A bat or tree survey can decide when work starts.
We give you a programme with the feasibility, alongside the budget. It is reviewed at each stage, so there are no surprises late on.
Five questions to ask before you start
Who will design the structure, the waterproofing and the lift pit? Will one firm answer for all three?
How will the cars get out if the lift is serviced? Where is the second way out for people?
Who serves the party wall notices, and when? And who prices the work, line by line, before you sign?
Handover is a lesson, not a key
We commission every system before handover. The lift maker tests the lift, and a service contract starts on day one.
You learn how the lift, the air and the alarms work. Then the gallery is yours. To see more, visit our basement car galleries page or BELOW.
For more information, head over to nuprojects.co. Fill out the contact form, or call 020 7731 6841.
This is the work we do. Basement contractors in London, or ask for a cost estimate.
Published 23 October 2026. Written by the NU Projects studio, edited since for house style and accuracy.