(1) The maximum height of the existing commercial premises as altered or added to must not be more than--(a) if there is a dwelling on an adjoining lot--8.5m, or(b) in any other case--(i) the maximum height applicable to the land on which the building is erected under another environmental planning instrument applying to the land, or(ii) if there is no such applicable maximum height--12m.
(2) Despite subclause (1), the maximum height of any ancillary development must not be more than 5m.