In 2001, the London Borough of Kensington and Chelsea received 46 planning applications for basement excavations; but in 2013 it received 450. This spike in applications might well have been what has prompted that council to review their planning policy.

It is evident from the rise of basement excavation applications in the capital that property owners see a basement excavation as an ideal way to improve their home and add value. Space remains scarce; and adding to one’s square footage is popular for many reasons.

Kensington and Chelsea have reacted to the rise in applications and on the 21 January 2015 the Council adopted a new policy for dealing with planning permission for basement development, Policy CL7: Basements, which forms part of the Local Plan.  A six-week consultation began in February and finishes on Wednesday 1 April 2015.  The draft policy has already been deemed “sound” by a government-appointed inspector. The policy is designed to help applicants make successful planning applications and for residents to understand the various issues that the Council will consider in assessing planning applications. It will replace the existing Supplementary Planning Documents on Subterranean Development (2009).

Kensington and Chelsea have decided to take action and it is likely that other planning authorities will follow suit in due course. In Kensington & Chelsea’s case, for example, the new policy is significantly more restrictive than existing. The following should be carefully considered if you are thinking about a basement excavation:

Neighbours

We would strongly recommend discussing any proposed building works with your neighbours at an early stage as you would not want to pay for an expensive scheme only to see it blocked. You may need to know if any restrictive covenants could come into play.

Planning Permission

Planning permission may (and very often will) be required and you will need to check with your local planning authority in order to ascertain their requirements.  There are many factors to consider such as is the property listed, in a conservation area, a building of townscape merit.

Party Wall etc. Act 1996

If other properties adjoin yours and share walls the Act requires that you send a party wall notice to notify the adjoining property owner well in advance of the works taking place.  You will need to instruct a party wall surveyor and your choice of surveyor should be carefully considered.

Building Regulation Approval

Not only do you need to employ the right builders you also need to ensure that you comply with building regulations which cover matters such as fire escape routes, ventilation, ceiling height, damp proofing, drainage, electrical wiring and water supplies.

Other Interests in the property

If you have a mortgage, a landlord, a tenant, and (presumably) a buildings insurance company, then you must involve the lender, your landlord, your tenant, and the insurers at an early stage.

In the light of the above we strongly advise that you seek advice before you break ground. This is not a comprehensive checklist of course; it should be considered a list of the bare minimum items to consider.

If you would like advice on any aspect of property law, please contact the partner at Hunters having responsibility for your legal matters, or (for new enquiries) please contact a member of our Property team.