31 Flavors of Inclusionary Zoning: Comparing Policies From San Francisco, Washington, DC, and Suburban Boston

As housing costs have risen in the U.S. and federal subsidies for affordable housing programs have declined, inclusionary zoning (IZ) has become an increasingly popular local policy for producing low-income housing without direct public subsidy. The structure of IZ policies can vary in a number of ways; consequently, there is not yet a consensus about what policies constitute “true” inclusionary zoning. In this paper we compare the ways in which IZ programs have been structured in three regions in which it is relatively widespread and long-standing. Our results demonstrate that IZ programs are highly complex and exhibit considerable variation in their structures and outcomes. In the San Francisco Bay Area, IZ programs tend to be mandatory and apply broadly across locations and structure types, but attempt to soften potential negative impacts with cost offsets and alternatives to on-site construction. In the Washington DC area, most IZ programs are also mandatory, but have broader exemptions for small developments and low-density housing types. IZ programs in the Suburban Boston area exhibit the most withinregion heterogeneity. In this area, IZ is more likely to be voluntary and to apply only to a narrow range of developments, such as multifamily or age-restricted housing, or within certain zoning districts. The amount of affordable housing produced under IZ varies considerably, both within and across the regions. The flexibility of IZ allows planners to create a program that accommodates local policy goals, housing market conditions and political circumstances.