An Bord Pleanála is the national independent appeals board. Where a Planning Authority issues a decision in respect of a planning application, any participant in the application can appeal the decision to An Bord Pleanála.
Guidance and documentation in order to make an appeal is available from an Bord Pleanála - link to the An Bord Pleanala website here
Information regarding making an appeal can also be found here (See Leaflet No. 5)