An Bord Pleanala has given permission for a huge development on the grounds of Dún Laoghaire golf club.
The development will consist of 856 apartments and houses, offices, shops, parks, roads and a crèche.
Local residents had objected to the scheme, but the planning body rejected their appeal this morning.
A number of conditions have been attached to the development which is expected to take ten years to complete. They include provisions to protect amenities and wildlife in the area.