endao,
Like Hal said, one option is to talk to the planning department. However, I recommend you have your homework done before you do...
Local needs is something of a grey area - Loosely speaking, it's dependant on your ties to the area, where you work, clubs/associations in the area you are incolved in etc...
If you live (and work) in Meath, your best bet is to buy and build in Meath. It would be possible to find a site in Kildare without a Local Needs clause but you'll pay a hefty premium for the privilidge (I can dig up a few samples if you want).