Although the DOE mandated at least SEER 13 as of January 2006, Ryland installed a SEER 12 in our home, which we purchased in May 2006. Also, our independent inspector stated the 4 ton A/C unit was too small for our 3,000+ sq foot, two level home. Industry standards dictate 1 ton per 500 sq feet. When we addressed this with Ryland, they gave us some circular logic and basically blew us off. After one year in the home, we are starting to have constant issues with regard to the inability to maintain an indoor temperature of 75 with outside temperatures as low as 78. Buyers beware.