For group housing situations with fewer than 10 units, the building should be treated similar to a large single-family home. In this case, all space within the building should be counted toward the HSA. For group housing situations with more than 10 units, the building should be treated as a multi-family building. In this case, only the living space within the individual dwelling units should be counted in the home size adjuster.
Updated 10/1/13 for rating system applicability.