The U.S. Department of Energy (DOE) issued a notice confirming the adoption of regional efficiency standards for residential furnaces, central air conditioners, and heat pumps. The rule sets different standards for the North, South, and Southwest regions of the United States. Under this rule the Seattle / Tacoma area is in the North region will have a gas furnace standard of 90 percent AFUE. Compliance with the standards will be required beginning May 1, 2013 for residential furnaces.
Beginning Jan. 1, 2015 minimum efficiency standards will be mandated for new central air conditioner and heat pump installations. See http://eetdnews.lbl.gov/nl19/eetd-nl19-5-furnaces.html for additional detail.