New to the 2009 edition is the inclusion of "live/ work" residences, and a requirement for carbon monoxide detectors in dwellings with attached garages or fuel -fired appliances. ICC code committees spent a lot of effort on clarification and uniform wording across the code format.

The 2009 MRC due out soon, will not follow the IRC lead for sprinkler coverage in new single-family homes. New to code reference, habitable attic provisions will allow residential structures with 5 habitable levels: A basement (below grade), three stories of living space and a habitable attic.