5. No provision of the 1991 Act brought into force by article 4 above shall have effect in relation to—
(a)any determination made before 25th September 1992 under section 51 of the 1972 Act as to whether planning permission is required, or any application made before that day for such a determination and any determination following on such an application, including a determination made on appeal;
(b)any established use certificate granted before 25th September 1992 under section 90 or section 91 of the 1972 Act, or any application for such a certificate made before that day and any certificate following on such an application.