Heres RECI's contact details, you'll find they're very helpful to contractors coming over from the UK
Register of Electrical Contractors of Ireland,
Unit 9, KCR Industrial Estate,
Ravensdale Park,
Kimmage, Dublin 12.
Tel: 353(0)1 492 9966; Fax: 353(0)1 492 9983
Wiring regs very similar to UK, TNC-S earthing (PME), etc etc,,
Theres a few Irish lads on this forum, we'll give you any advice you'll need...
Is it commercial or domestic?? Why not sub it out ??