15.—In this Chapter—

“user” has the meaning assigned by section 19(1)(a)(ii);

“works” includes any activity which destroys or which significantly alters, damages or interferes with the integrity of—

(a) a site, or

(b) any of its species, communities or habitats,

either intentionally or unintentionally, or any activity which has a significant impact on the site or on any of its species, communities or habitats, or on its landforms or geological or geomorphological features, or on its diversity of natural attributes, other than development by a local authority or development which is not exempted development for the purposes of the Planning and Development Act 2000.