Conversion of roof space to form 1no 3 bedroom flat and 1no 2 bedroom flat and associated roof alterations including raising ridge height, removal of central chimney, new dormers to East, North and West elevations and roof lights to South elevation. External alterations including two storey rear and side infill extension and creation of basement accommodation and courtyard, in order to allow the reconfiguration existing flats on ground and first floors. (retrospective to address non-compliance with condition 6 in relation to permission ref. BH2017/01899). (Amended description).