Matthew Sammon writes about using John Handelaar’s service for converting Irish street names to coordinates. He has very good points, but a few provisos:
It is only half true to say that Geodirectory covers every postal address in Ireland and links it to a coordinate. In fact, it links every inhabited building in Ireland, which is not quite the same thing. 40 percent of these buildings have non-unique addresses, i.e., they don’t even have an address of their own.
The biggest issue with Handelaar’s address-mangler is that such a large proportion of houses in Ireland are not on a named street. They are addressed relative to townlands. This isn’t purely a content issue, it’s an issue about the structure of geographical information in Ireland.
One other thing: there is no guarantee of uniqueness of streetnames within Dublin postcodes. For example, there are two Pembroke Cottages within Dublin 4 (Ringsend and Donnybrook). There are two James’s Places in Dublin 2 (one is off Baggot St., the other is a new building on the quays.)