Planning permission for an underground garage in the UK
An underground garage almost always needs planning permission in the UK. In prime London the borough policies limit a basement to one storey and 50% of the garden. Country houses face green belt, landscape and listed building tests instead.
This guide sets out the rules that matter, with policy numbers and sources. Policies are reviewed and renumbered, so check every rule below against the council's current adopted local plan before you rely on it.
Updated
Why permission is almost always needed
Planning guides make three general points. Excavation that changes how a house looks, such as new light wells, is likely to need permission. Underground development in a front garden needs permission. Permitted development freedoms are taken away for listed buildings and in National Parks and National Landscapes.
These points come from secondary guides, so confirm them with the Planning Portal and your planning consultant. In practice, a car gallery with a lift, a ramp and a pavilion is a full planning application.
London: the borough basement policies
The three prime central boroughs have similar caps. Each limits a basement to one storey and half the garden, with different detail.
| Borough | Policy | Depth | Garden | Other points |
|---|---|---|---|---|
| Kensington and Chelsea | Local Plan Policy CL7 | One storey, with exceptions possible on large sites | Up to 50% of each garden, with the rest left in one area | Adopted January 2015, replacing an 85% limit. Basements under listed buildings are restricted. |
| Westminster | City Plan Policy 45 | One storey below the lowest original floor, with an exception for large sites with good construction access | Up to 50% of garden land, or up to 4m from the building where the garden is 8m deep or less | At least 1m of soil plus a 200mm drainage layer on top. No more than 1.8m under the highway. Structural stability, flooding and heritage must be addressed. |
| Camden | Local Plan Policy A5 | One storey | No more than 50% of each garden, and no more than 50% of its depth | Garden includes driveways and paved areas. Exceptions for large, comprehensively planned sites. Under review at the current Local Plan examination. |
Kensington and Chelsea brought in its policy after basement applications rose from 180 in 2010 to 393 in 2014. In one Hampstead pre-application case, an existing garage footprint was counted as garden, which pushed a proposed basement garage over Camden's 50% limit.
Our page on underground garages in London explains what these limits mean for a gallery.
A London precedent for a car lift
Kensington and Chelsea granted planning permission and listed building consent for a two-car pop-up car lift beneath the road at Thurloe Place, South Kensington. A turntable sits at ground level. Neighbours asked the High Court to quash the permission, and the court refused.
The case shows that a car lift can win consent in a sensitive, listed setting when the design is right.
Country houses: green belt, landscape and listed buildings
Outside London the borough one-storey caps do not apply, but other tests do. In the green belt, national policy treats new buildings as inappropriate, subject to exceptions. Inspectors ask whether a proposal is inappropriate development, and whether any harm is clearly outweighed.
Whether the work can be seen from outside the site is one of the factors they weigh. A garage that sits wholly below ground, with the lawn restored over it, has a strong case on openness.
The case is not automatic. In a Nottinghamshire appeal, a basement in a replacement house was judged an inappropriate increase in size. Some inspectors count basement floorspace when they test whether an addition is disproportionate.
In a National Landscape the question is landscape impact. For a listed house, listed building consent is a separate layer on top of planning permission.
A Surrey precedent: the 70m garage
In 2019, a Surrey homeowner won permission on appeal for a subterranean garage of about 70m, or 230ft, under the house. It included a car lift, a turntable, a workshop and an art gallery.
The owner had been refused about seven years earlier. The appeal succeeded on the argument that the garage was an engineering operation. A neighbour had objected on noise and disturbance. Our page on underground garages in Surrey covers the country house route in more depth.
What an application usually needs
- Drawings of the basement, the lift and any pavilion or lid, shown with the house and garden.
- A structural report and construction method, covering the neighbours' foundations.
- Drainage and flood evidence.
- A Basement Impact Assessment, where the council asks for one.
- A Construction Management Plan covering lorries, noise and working hours.
- Heritage evidence in a conservation area, and listed building consent for a listed house.
- Landscape and visual evidence in the green belt or a National Landscape.
- Tree and soil evidence where the garden is affected.
Party wall matters with neighbours run on their own track, alongside planning.
How BELOW handles planning
We design the gallery with the house and garden, and prepare the application with our architects and engineers. We check the current adopted plan for your council at the start, because basement policies change.
The planning route also shapes the budget and the programme. Our underground garage cost guide and residential car lift guide explain how.
Questions
- Do I need planning permission for an underground garage?
- Almost always. Excavation that changes how a house looks needs consent, and so does underground work in a front garden. A car gallery with a lift or ramp is normally a full planning application.
- How deep can a basement garage be in London?
- In Kensington and Chelsea, Westminster and Camden, the main basement policies allow one storey. All three allow exceptions on some large sites.
- Can I build under my whole garden in London?
- Not in those three boroughs. Each limits a basement to 50% of the garden, and Camden also limits it to 50% of the garden's depth. Camden counts driveways and paved areas as garden.
- Can I build an underground garage in the green belt?
- It is possible, but each case is tested on its merits. A 2019 Surrey appeal allowed a 70m underground garage as an engineering operation. Other inspectors have counted basement floorspace against a proposal.
- Does a listed house rule out a car lift?
- No. It adds listed building consent to the application. The Thurloe Place car lift in South Kensington won both planning permission and listed building consent.
Sources
- Self-Build, Do I need planning permission to build a basement?
- Mondaq, Garage dilemma
- Royal Borough of Kensington and Chelsea, basements planning policy
- Rodic Davidson, End of mega-basements in Kensington and Chelsea
- Edwin Coe, Limiting the size and scope of basement excavations
- OLBC, New basement planning laws
- Ladbroke Association, Current RBKC policies on basements
- Westminster City Plan Policy 45, policy summary
- Local Government Lawyer, Westminster consultation on basement policy
- London Borough of Camden, planning document on Policy A5 basements
- Camden Local Plan examination, Matter 7 basement representation (5 March 2026)
- Planning Resource, High Court rejects neighbours' bid to overturn pop-up car lift permission
- The Negotiator, Surrey subterranean garage wins planning on appeal (2019)
- Mineral and Waste Planning, basement floorspace judged inappropriate in the green belt
- Appeal decision, The Coach House, Withnell (June 2014)