Surveying started in 1991 and focused first on towns. The first survey was performed in
County Clare. Each building covered by one of the surveys is rated on a scale that includes the values "record only", "local", "regional", "national", and "international" where usually objects of at least regional significance are considered for protection. In 2001, then minister
Síle de Valera used the result of these surveys to recommend the inclusion of 2,155 buildings in the record of protected structures by the respective planning authorities. As a full survey of the entire country using the same approach as for the town surveys was assumed to take more than 100 years, it was decided to begin with interim county surveys that focused on buildings with at least of regional significance. The surveys were published on
CD-ROMs and online. The dataset has been published under the
Creative Commons Attribution 4.0 license. In addition, a series of books was published, each presenting the highlights of one of the surveys. As of 2017, 33 volumes were published. Another surveying project of the NIAH focuses on historic gardens and designed landscapes. These surveys started by comparing the 19th-century maps of the
Ordnance Survey against aerial photography and were followed by on-site evaluations. In June 2009, the NIAH won the
Europa Nostra Award for this project. == See also ==