More on Rental Housing Association (RHA)… RHA’s membership consists of over 500 multi-family industry professionals who own or manage over 100,000 rental units in Massachusetts. RHA is one of five divisions of the Greater Boston Real Estate Board, which has a combined membership of over 6,000 real estate professionals. Other divisions of GBREB include Building Owners and Managers Association (BOMA), the Commercial Brokers Association (CBA), Greater Boston Association of REALTORS®, and the Real Estate Finance Association (REFA).