March 2016 - IRIS v4.0 Released (current version)
Immaterial change. Minor revision to definition language in order to align consistency of metric with catalog's structure and style.
March 2014 - IRIS v3.0 Released
Immaterial change. Minor revision to definition language for clarity.
November 2011 - IRIS v2.2 Released
February 2011 - IRIS v2.1 Released
September 2010 - IRIS v2.0 Released
Immaterial change. Housing Type (PD2532) replaced Housing Units: Type (CD4.2). IRIS ID / metric name changed due to framework upgrade. Minor revision to definition language for clarity.
September 2009 - IRIS v1.0 Released
New metric. Housing Units: Type (CD4.2) developed via Original IRIS Working Group.