City council consults on planning policy aimed at reining in 'mega-basements'

Westminster City Council is to consult on a planning policy aimed at arresting the growth in ‘mega-basements’, which have been likened to "the decks of a nuclear submarine".

Under the policy, contained in the local authority’s new local plan, basement extensions of more than one story and over 50% of a property’s garden size would be recommended for planning refusal.

The council will also seek to enforce a 1.2m minimum depth of soil between a garden and the roof of a basement extension.

Westminster reported an increase of more than 125% in applications for basement extensions between 2008/09, when there were 79, and 2011/12, with 181.

“Some basements have as many as three stories and their construction can cause huge problems and discomfort for neighbours,” it claimed.

Westminster said that new basements needed to provide naturally lit, well ventilated accommodation with no negative visual impacts on surrounding areas.

The council hopes to implement the new rules by 2015, adding that it would be “the first in the UK to tackle the issue of mega-basements in a pragmatic way”.

Cllr Robert Davis, deputy leader of Westminster City Council, said: “This is about restricting developments akin to the decks of a nuclear submarine that are too large and cause real disruption for our residents. 

“Currently the national planning guidance allows developers and homeowners to just down periscope and build whatever size they like – our residents have asked us to tackle this issue, and this is what we are doing.”