20 Lionel Mansions, Haarlem Road, London, W14 0JH

Demolition of the single storey back addition and rear outbuildings attached to the rear of the main building; erection of side and rear extensions at lower ground, upper ground and first floor level, erection of a rear roof extension to replace the existing dormer window, excavation beneath the main building in connection with the creation of a new basement and the formation of a roof terrace at upper ground floor level to the main building; change of use of the main building from office (Class E) into 2 x two bedroom self-contained flats; erection of a part one storey plus-basement single family dwellinghouse in the rear garden; erection of a new boundary wall with three new entrances to the side elevation; associated landscaping and external alterations.

Submission of details of a noise assessment of external noise levels, including reflected and re-radiated noise and details of the sound insulation of the building envelope, orientation of habitable rooms away from major noise sources and of acoustically attenuated mechanical ventilation as necessary to achieve internal room and external amenity noise standards in accordance with the criteria of BS8233:2014 pursuant to condition 6 of planning permission ref: 2024/03159/FUL granted 12th December 2025.

NMAT