Extension and external alterations to rear portions of building to facilitate change of use from offices/training/storage to three self-contained flats, with retention of ground floor retail/commercial unit. External alterations including demolition of existing flat roof building to north and flat roof extension to south, erection of a single storey extension to north elevation including first floor terrace and external stair, erection of four dormers to south, alteration to roof of building to east and installation of new/replacement windows and doors.