Inclusionary zoning policies encourage the production of affordable housing by requiring or encouraging housing developers to build residential developments where a certain percentage of the housing units are affordable to low or moderate income residents. This affordable housing is offered in exchange for building incentives, such as density bonuses that allow developers to build a greater number of units than is otherwise allowed, or fast-track permitting that allow for a faster pace of development. To be effective at producing housing for those at risk for homelessness, inclusionary zoning plans should: 1) Be mandatory, 2) Make some of the units available to those making less than 30% of median income, 3) Keep units affordable long-term – at least 25 years.

• Over 40 years ago, the County Council of Montgomery County, Maryland passed a Moderately Priced Dwelling Unit Ordinance that is still in effect today. The law requires that all new housing developments of 20 or more units devote between 12.5% and 15% of their units to affordable housing as “moderately priced dwelling units” (MPDUs). While the set-aside is mandatory, the law does permit developers to instead contribute to a housing fund in special circumstances under Sec. 25A-5A. Homeownership MPDUs are required to remain affordable for 30 years, and rental MPDUs for 99 years (See Sec. 25A-3(g)). The program has resulted in more affordable units than any other program in the country (currently 14,029), and has not been challenged in court. According to a report produced by Business and Professional People for the Public Interest, in total the program has created “over 11,500 affordable units since 1973 and has generated $477.4 million of private sector investment in affordable housing.” For a more thorough analysis of this successful program, please see “Strengthening the Moderately Priced Dwelling Unit Program: A 30 Year Review” a 2004 report submitted to the Montgomery City Council.
• Boulder, CO passed an inclusionary zoning ordinance that requires 20% of the units in multi-unit housing projects be set aside as permanent affordable housing; however, developers can request an exemption from this requirement by contributing to a housing fund or pursuing a number of alternative methods of compliance that have been approved by regulation.
• The Napa County, California passed an inclusionary zoning ordinance requiring developers to either devote 10% of new units to affordable housing or contribute to an affordable housing fund.  In 2001, the ordinance survived takings clause and due process challenges in Homebuilders Association of Napa v. City of Napa.  
• As a result of the Supreme Court of New Jersey’s decision in Southern Burlington County N.A.A.C.P. v. Mount Laurel Township, all municipalities in New Jersey are required to devote a “fair share” of their housing to affordable units. To assist municipalities in fulfilling their “fair share” obligation, the New Jersey Department of Community Affairs has issued a Sample Affordable Housing Ordinance.

• "Opening the Door to Inclusionary Housing: A comprehensive guide for municipal governments and affordable housing advocates to explore the     feasibility of an Inclusionary Housing Program in their communities” produced by Business and Professional People for the Public Interest
• “Inclusionary Zoning: A Viable Solution to the Affordable Housing Crisis?” produced by the Center for Housing Policy
• “Expanding Affordable Housing through Inclusionary Zoning: Lessons from the Washington State Metropolitan Area” produced by the Brookings Institution Center on Urban and Metropolitan Policy
• “Voluntary or Mandatory Inclusionary Housing? Production, Predictability, and Enforcement” produced by the Business and Professional People for the Public Interest
• "The Inclusionary Housing Debate: The Effectiveness of Mandatory Programs Over Voluntary Programs" produced by the American Planning Association
• Inclusionary Housing Advocacy Toolkit produced by the Nonprofit Housing Association of Northern California
• Inclusionary Housing Initiative Toolkit produced by Business and Professional People for the Public Interest
• Inclusionary Zoning – Legal Issues produced by California Affordable Housing Law Project
• California Coalition for Rural Housing is currently developing an inclusionary zoning database.
• Inclusionary Housing Factsheet produced by Business People for the Public Interest
• Additional publications on inclusionary housing that have been produced by the Center for Housing Policy
• Additional publications on inclusionary housing produced by Business People for the Public Interest
• Additional publications on inclusionary housingproduced by California Department of Housing and Community Development

• “Framing Inclusionary Zoning: Exploring the Legality of Local Inclusionary Zoning and its Potential to Meet Affordable Housing Needs” 36 No. 4 Zoning and Planning Law Report 1, published in 2013o   “Exclusionary and Inclusionary Zoning” 3 Am. Law. Zoning § 22:42 (5th ed.) (discusses court challenges to several mandatory inclusionary zoning policies)
• “Mandatory Inclusionary Zoning – the Answer to the Affordable Housing Problem”  33 B.C. Envtl. Aff. L. Rev. 383 (discusses court treatment of inclusionary zoning and also includes an overview of mandatory and non-mandatory inclusionary zoning policies)