Homeowners planning basement dig-downs may require planning permission following a significant judicial ruling. The judge concluded that any basement extension requiring excavation and engineering works could not be built under ‘permitted development’ rules.

Architects and surveyors designing dig-downs should advise their clients about the ruling or risk complaints if their client incurs significant design costs but fail to secure planning permission.

Basement dig-downs are popular in London, due to limited space and high property prices.  But they have proved controversial with neighbours, concerned about construction disruption and the risk of damage to their homes.  Smaller single story dig-downs have often been approved under permitted development rules, with larger multi story basements, or those extending beyond the property’s boundary requiring planning permission.

Kentish Town resident, Michael Eatherley, brought a judicial review against his neighbour who planned a single story basement in his North London Victorian cottage.  Mr Eatherley challenged Camden Council’s decision to allow the extension under the permitted development rules, rather than requiring full planning permission.

The High Court ruled in favour of Mr Eatherley.  The judge accepted Mr Eatherley’s claim that the proposed work included major engineering works which were not allowed under permitted development rights.

It seems to me that the development of a new basement, when there is nothing underneath at present, could well amount, as a question of fact and degree, to two activities, each of substance.  There is the enlargement, improvement and alteration aspect, but there is potentially also an engineering aspect of excavating a space and supporting the house and its neighbours,” said Justice Cranson.

Architects and surveyors must take this ruling into account when they are advising clients about dig-downs, if they are to avoid the risk of complaints,” said James Burgoyne, Director – Claims & Technical, Brunel Professions.  “It would be prudent for them to advise their clients to seek planning permission early in the process.  It is likely that permission will be needed for the vast majority of projects, especially if engineering works are required as well as excavations.”

Reports on the case have been published by Architects Journal, the Financial Times, Telegraph and the BBC.

Brunel provides a wide range of PII broking services to construction professionals.  Click here to find out more, or call Jonathan Filer on +44 (0)117 325 0752.