Basement drawings for a London house, £1,729 in total
A basement is the most closely watched residential project in London: boroughs limit its size and ask for method statements, and neighbours worry about their foundations. We measure the house and draw the application: £1,579 plus the £150 survey.
- £1,579 drawings + £150 survey (£1,729 total)
- Neighbour impact drawn early
- Free redraws until approval
What do basement drawings cost in London?
The planning set is £1,579 and the survey £150, £1,729 in total with no VAT to add. It is our dearest drawing set because it combines a design, the section through the ground and the supporting information a borough demands. Engineer’s reports and the council fee are separate, and we say which you need.
In the £1,729
- A measured survey of the house, the existing cellar and the garden levels
- Existing and proposed plans for the basement and ground floors
- Sections through the new floor, the lightwell and the foundations of the neighbours as far as can be seen
- A site plan showing the basement footprint against the garden and the percentage of garden it takes
- Drainage, lightwell and stair layout
- Forms and submission, with free redraws until approval
Is a basement planning permission or not?
Digging out a new level counts as development, so you need planning permission: the Act carves out interior works but not additional space underground (section 55). Simply fitting out an existing cellar is different and may not need it. We establish which you have on the survey day.
What the borough asks for
Each borough has its own limits. Kensington and Chelsea caps a basement at half the garden and one storey, and wants a metre of soil above it for drainage (Local Plan 2024, policy CD11). Camden, Westminster and others add a basement impact assessment, a construction method statement and a traffic plan.
- Footprint against garden area
- Depth and number of floors
- Lightwell size and position
- Flood risk and groundwater: ask for the borough’s requirements
Neighbours, engineers and building control
Digging near a neighbour’s foundations triggers the Party Wall etc. Act, with at least one month’s notice. We prepare those notices at £39 per owner. A structural engineer is essential: see structural calculations. Technical drawings follow as building regulations drawings.
What boroughs and the Act ask of a basement
- 50%
- Kensington and Chelsea’s basement policy limits a basement to 50% of each garden or open part of the site, and the unaffected garden must be in one area. RBKC Local Plan 2024, Policy CD11 (criterion A)
- 1 m
- The same policy needs at least one metre of soil above any part of a basement beneath a garden. RBKC Local Plan 2024, Policy CD11 (criterion J)
- 3 m
- Excavation within 3 m of a neighbour’s building that goes below the bottom of its foundations needs notice under the Party Wall etc. Act. Party Wall etc. Act 1996, s.6(1)
- 6 m
- Excavation within 6 m that meets a 45 degree line from the neighbour’s foundations also needs notice. Party Wall etc. Act 1996, s.6(2)
- 1 month
- The notice under section 6 must be served at least one month before excavation starts. Party Wall etc. Act 1996, s.6(5)
- £548
- The council fee for a householder application from 1 April 2026. National fee schedule from 1 April 2026, published by Bradford Council
- Interior works
- Works affecting only the interior of a building are not development, but adding space underground begun after 5 December 1968 is. Town and Country Planning Act 1990, s.55(2)(a)
Basement questions
Do I need planning permission to convert an existing cellar?
Not always. Interior work is not development, but a new level, a lightwell or external change usually is.
Can I build a basement under the whole garden?
In many boroughs no. Kensington and Chelsea, for one, limits it to 50% of the garden.
Do I need an engineer?
Yes. A basement affects the foundations of your house and next door, so a chartered structural engineer designs it and signs the calculations.
Does the £1,729 include the engineer?
No. We coordinate with the engineer, but their fees and any impact assessment are separate and quoted by them.
What notices do I serve?
Party wall notices for each adjoining owner, at least one month before digging starts.
Source: Party Wall etc. Act 1996, s.6
Other services people book with this one
Can your house take a basement?
Send the postcode and say whether a cellar already exists. We check the borough’s limits and reply with a fixed fee.