Inclusionary Housing Map Supports the Scale of Housing with Lasting Affordability

For urban planners in the US, inclusionary housing (also known as inclusionary zoning) is a familiar regulatory measure that many local governments employ as a proactive approach to provide below-market-rate residential units and foster mixed-income communities.

In its simplest form, this type of policy requires or incentivizes developers to provide a portion of newly constructed homes priced at a below-market rate that is affordable to lower-income home buyers or renters. These homes are important in the effort to address the severe affordable-housing crisis in the US. In 2019, 29 percent of all households in the country spent more than 30 percent of their income on housing—a threshold that is defined by the US federal government as housing cost burden. Housing cost burden has disproportionately impacted lower-income families and people of color, placing them at greater risk for displacement, eviction, and homelessness.

Inclusionary housing stands out from a large toolbox of affordable housing strategies because new construction tends to be in higher-income or evolving neighborhoods with growing amenities. The inclusionary units contribute to racial and economic inclusion and provide access to opportunity for residents in affordable housing. Studies find that over 90 percent of inclusionary housing policies require homes to be affordable for at least 30 years. Long-term housing affordability is key to maintaining residential and neighborhood stability, which has proved to be fundamental to people's well-being and success.

These policies vary widely in design and effectiveness across cities and states. The diagram below shows five policy features—a small subset of examples in a long list—that influence affordable units produced under inclusionary housing policies. As communities move to adopt these policies, they need information on what works and what doesn't. Historically, the absence of a nationwide database precluded policy makers from knowing what policies other cities were implementing and what the outcomes were. Consequently, many cities ended up reinventing the wheel—adopting policies that fell short of expectations—or hesitated to create a policy altogether. 

To address this knowledge gap, Grounded Solutions Network, a national nonprofit organization advancing racial equity through long-term affordable housing, has completed a national survey of inclusionary housing programs and compiled a comprehensive dataset for the field. With this amazing dataset in hand, the organization discussed how to share the data with a national audience in a way that was clear and concise. Also, there was the desire to make the dataset searchable by region and program characteristics, and to show what the underlying state policy context was like.

With these inquiries in mind, the lead Grounded Solutions researcher, Dr. Ruoniu "Vince" Wang, built the Inclusionary Housing Map using Esri's ArcGIS Online, a web-based mapping software as a service for creating and sharing interactive maps. This interactive map enables users to visualize where over 1,000 inclusionary housing policies are enacted as well as to easily view policies of interest for further information on their characteristics and outcomes. There is also a layer in the map containing data on state-level legislation and judicial decisions that are related to the adoption of inclusionary housing policies. Having both individual program information and state contextual information in one place—and being able to visualize it on an interactive map—helps users comprehend which places hold the potential for inclusionary housing adoption and how certain policies reach impressive affordable-housing results in states with less favorable legal landscapes.

Wang admits that the map may be incomplete. "It is possible that the surveys missed policies, particularly small policies or voluntary policies that go by another name such as 'density bonus policy,'" he said. Plus, new policies are being enacted all the time. To address this, the map serves as a mapping tool for viewers to report new and/or updated policies. Grounded Solutions staff then update the mapping tool periodically based on these inputs.

"This [tool] will advance the field and spark interest among more sites to connect and learn from one another," said Alexandra Curley, a scholar from National Initiative on Mixed-Income Communities at Case Western Reserve University. Indeed, the mapping tool has drawn wide reception. Shortly after its launch in 2018, the mapping tool was linked to over 30 different external websites with a total of 500 mentions. Multiple industry-leading outlets have featured the tool, including National Low Income Housing Coalition, Next City magazine, National Housing & Rehabilitation Association, and Affordable Housing Finance magazine. To date, the tool has attracted over 20,000 viewers including policy makers, planners, affordable-housing practitioners, reporters, and researchers.

The development of the Inclusionary Housing Map reflects the overarching movement toward data democratization in our society. Making datasets transparent and accessible is a welcome and increasingly frequent practice in many fields and has been witnessed in the affordable housing field in recent years. As part of the data democratization process, one noticeable trend is data visualization. Many affordable housing organizations in the US are using ArcGIS Online to visualize where affordable housing is located. Examples include the National Housing Presentation Database and, in Florida, the Assisted Housing Inventory Map. The Inclusionary Housing Map supplements these by providing detailed information on an important local-level affordable housing policy solution that was not previously available but could be used for the entire nation.

The Inclusionary Housing Map is an important monitoring mechanism to support the organization's vision for "Lasting Affordability Now: Our Path to Racial Equity," which  Grounded Solutions Network's vision calls for rapidly expanding the scale of housing with lasting affordability by achieving at least 1 million new homes over the next decade.

The Inclusionary Housing Map documents about 110,000 affordable units, and this number is growing as affordable housing units are created to comply with both new and existing inclusionary housing policies. As well as updating the datasets under the map periodically, Grounded Solutions Network has been evaluating and incorporating improvements to the map in alignment with ArcGIS Online.