Case Study : Extension to Grade I Listed Building


Plainview Planning was instructed to rectify a serious breach of planning control at a Grade I listed property.


Change of Use; Appraisal and Strategy; Planning Application; Specialist Reports; Listed Building; Enforcement; London.


City of Westminster


A modern extension had been constructed without the discharge of pre-commencement conditions. This left our client in a very vulnerable position – unauthorised works to a listed building is a crime.

The situation was further complicated by the Grade I status of the building; designed by John Nash, this particular terrace has been identified as one of Nash's most scholarly designs due his treatment of Doric porticoed pavilions, rusticated loggia and the continuous entablature.


We argued that the extension did not negatively impact on the built fabric which held the principal interest of the heritage asset. The extension was appropriately subservient to the architecture of the rear façade and furthermore, could not be viewed from the public realm.

The City of Westminster agreed with our conclusion that the glazed extension had little effect on the setting of the heritage asset and retrospective planning permission was granted.