Housing minister has confirmed that landlords are not allowed to use AirBnB without planning permission:
Landlords are not allowed to use Airbnb for the short-term letting of their properties unless they get planning permission for bed and breakfast or hotel status, Minister for Housing Simon Coveney has confirmed.
http://www.irishtimes.com/news/politics/oireachtas/landlords-need-permission-for-airbnb-lets-minister-confirms-1.2914873
So this means all landlords currently using AirBnB without planning permission, will need to stop using AirBnB, and either seek planning permission or make other use of their property - otherwise they will be illegally renting out their property.
Seems to warrant its own thread, but if mods disagree please feel free to move or merge elsewhere.