Any application to vary the implementation time limit condition on a DNS planning permission would have to be made to the Welsh Ministers via the DNS process - see Regulation 51 of the DNS Regulations
Byddai’n rhaid i unrhyw gais i amrywio’r amod ynghylch terfyn amser gweithredu ar ganiatâd cynllunio DNS gael ei wneud i Weinidogion Cymru trwy’r broses DNS – gweler Rheoliad 51 y Rheoliadau DNS