5.—(1) Where the Minister considers that compliance with any requirement of building regulations would be unreasonable in relation to any specified class of building operation, works or material, the Minister may, as regards such compliance, by order dispense with or relax that requirement subject to such conditions as he sees fit and specifies in the order.

(2) The Minister may by order amend or revoke an order made under this section including an order made under this subsection.