How many units? For the purpose of 2010 CBC Chapter 11A requirements, covered multi-family dwellings are defined to include apartment buildings with 3 or more units and/or condominiums with 4 or more dwelling units (Section 1102A.1). So, if the apartment building has 3 dwelling units, Chapter 11A requirements will apply. However, if only 3 condominium units are proposed, the requirements will not apply. Hope this helps.