25   Conservation incentive relating to heritage items

(1)  Nothing in this plan prevents the council from granting consent to:

(a)  the use for any purpose of a building within a conservation area or of the land on which that building is erected, or

(b)  the use for any purpose of a building that is an item of the environmental heritage or of the land on which that building is erected,

      where the council is satisfied that:

(c)  the use would have little or no adverse effect on the amenity of the area, and

(d)  conservation of the building depends on the council granting consent in pursuance of this subclause.

(2)  The council, when considering an application for consent to erect a building on land upon which there is a building which is an item of the environmental heritage, may at its discretion exclude from its calculation of the floor space of the buildings erected on the land the floor space of the item of the environmental heritage:

(a)  for the purposes of determining the floor space ratio, and

(b)  for the purposes of determining the number of parking spaces to be provided on the site,

      but only if the council is satisfied that the conservation of the item depends upon the council granting consent in pursuance of this clause.