An interim heritage order made in respect of an item may be expressed to apply (and if so expressed does apply) to--
(a) if the item is a building--the curtilage of that building or the site of that building, being the curtilage or site specified or described in the order, or
(b) if the item is a work or a relic that is attached to or forms part of land--the site specified or described in the order for that work or relic.