CHAPTER 40B HANDBOOK FOR ZONING BOARDS OF APPEAL Chapter 1. Intrroduction home values and rents appreciate during robust market conditions. The units retain their affordability under a deed restriction that lasts for many years, if not in perpetuity. Both types of modestly priced housing meet a variety of needs. However, the market determines the price of unrestricted affordable units while a recorded legal instrument regulates the price of Chapter 40B deed restricted units. Any household (regardless of income) may purchase or rent an unrestricted unit, but only a low- or moderate-income household may purchase or rent a Chapter 40B deed restricted unit. Housing units generally qualify for listing in the SHI if they are subsidized under an eligible subsidy program, subject to an affordable housing restriction that controls sale prices or rents and limits occupancy of the units to income-eligible households, and made available to income-eligible people on a fair, open basis in accordance with an affirmative fair housing marketing and resident selection plan (AFHMP). Although comprehensive permits and public housing authority developments account for most units on the SHI, there are other ways to produce SHI Eligible Housing. For example, some communities have created low- or moderate-income units with inclusionary zoning, by issuing special permits, or by using Community Preservation Act (CPA) funds to acquire older homes and resell them to low- or moderate-income homebuyers, subject to a deed restriction that keeps the units affordable over time.