Installation of 1no. roof mounted vertical discharge centrifugal fan enclosed in 1250mm high timber fence, on top of the flat roof of the single storey rear extension at first floor level; raising the height of parapet walls of the single storey ground floor rear extension by 150mm in brickwork with 35mm deep coping stone on top.

Installation of 1no. roof mounted vertical discharge centrifugal fans and 1no. condenser units on the flat roof of the single storey rear extension at first floor level.