If you know the Eircode because the person who lives there told you, you can add that to the building which will fix some of the issues.  However as https://wiki.openstreetmap.org/wiki/Ireland says, "Do not use the official online tools to find and map Eircodes, as this represents a copyright infringement!".
https://nominatim.osm.org/ui/reverse.html?lat=54.251661258189046&lon=-7.141424417495728 shows more detail.
