This property you are looking at is probably an IRC Home. They are a offsite built home. However International Residential Code was used as the guidelines for these homes. Most are 2x6 construction and have all the structural integrity if not more than a site built home. Don't be afraid to look at this if it fits your needs. If you would like to talk with me further about these construction methods. You can reach me at 970-640-4772 15 years as a builder and now a broker.