12. If an initial notice ceases to be in force as described in section 47(4)(b) of the 1984 Act (cancellation etc. of initial notice) and the conditions in section 53(2) of the 1984 Act (plans certificate given, accepted and not rescinded) are satisfied, the local authority may not—
(a)give a notice under section 36(1) of the 1984 Act (removal or alteration of work which contravenes building regulations), or
(b)institute proceedings under section 35 of the 1984 Act for a contravention of building regulations,
in relation to any work described in the certificate which has been carried out in accordance with the plans to which the certificate relates.