Section 26H of the Planning (Listed Buildings and Conservation Areas) Act 1990 (“the 1990 Act”) provides that anyone who wishes to ascertain whether proposed works for the alteration or extension of a listed building would be lawful (i.e. that the works would not affect the character of the listed building as a building of special architectural or historic interest) may make an application to the local planning authority, describing the works, in order to receive a formal response – a certificate of lawfulness of proposed works. Section 26H broadly mirrors the provisions of section 192 of the Town and Country Planning Act 1990 (“the 1990 Act”) in respect of certificates of lawfulness of proposed use or development in the planning system.