The motion - carried by a vote margin of 227 to 97 - allows the GAA's Central Council the power to open up the 82,3000-capacity Croke Park to other sports, while Lansdowne Road is redeveloped.
In a statement, the IRFU said: "The Irish Rugby Football Union has always stated that during the proposed re-development of Lansdowne Road that it would investigate its options of temporary accommodation, both inside and outside the country, taking account of the logistical and commercial perspectives.
"The Union respects that the availability of Croke Park was entirely at the discretion of the GAA and its members and appreciates and welcomes the change in policy that Croke Park may now become available for the staging of other sporting events."
