(b) where a relevant notification provision on an individual building has been given before 23 November 2022 provided the work for each building is started before 23 November 2023
(b) os rhoddwyd darpariaeth hysbysu berthnasol ar adeilad unigol cyn 23 Tachwedd 2022, cyhyd ag y bo’r gwaith ar gyfer pob adeilad yn dechrau cyn 23 Tachwedd 2023