Across the country, housing organizations are working to preserve existing affordable housing while expanding supply. For many, data plays a critical role in understanding where risks exist and how to respond.
For The Housing Collective, the National Housing Preservation Database (NHPD) has become a key tool in that effort, helping their team identify at-risk properties, inform policy discussions, and guide preservation strategies across Connecticut.
What is the National Housing Preservation Database?
Maintained in partnership with the Public and Affordable Housing Research Corporation (PAHRC), HAI Group's research division, and the National Low Income Housing Coalition (NLIHC), the NHPD provides access to de-duplicated information on federally assisted housing inventory across the United States. Their most recent jointly released report, the Picture of Preservation, explores the federally assisted housing stock, preservation risks these properties face, and federal policies that can support affordable housing preservation.
A systems approach to housing and preservation
The Housing Collective is a Connecticut-based nonprofit focused on strengthening housing systems and expanding access to safe, affordable homes. Their work brings together a wide range of partners to address housing challenges at multiple levels, convening and aligning with more than 225 partners—including municipalities, developers, service providers, resident leaders, and philanthropy—to strengthen housing systems across multiple regions of Connecticut, according to Caroline Wells, AICP, regional planner at the Center for Housing Opportunity, a Housing Collective program.
The Collective's work spans the full housing continuum, from coordinating homeless response systems to advancing policy and increasing housing supply. Rather than focusing only on new development, their approach recognizes that solving housing challenges requires protecting the homes that already exist.
“Thousands of existing affordable homes are at risk each year of converting to market rate as affordability restrictions expire," Wells explained. "Preserving these homes protects prior public investment, prevents displacement for vulnerable residents, and stabilizes communities.”
Using data to shift the conversation
The Housing Collective began using the NHPD in 2018 as part of a broader effort to engage partners and better understand housing challenges across the state. According to Wells, the database has since turned into a foundational resource for her team.
“The NHPD quickly became one of the most useful tools available to us," Wells said. "It allowed us to see the portion of Connecticut’s affordable housing stock that is supported by public subsidies and subject to affordability restrictions, along with when those restrictions might expire.”
Wells continued, "At the time, many housing discussions focused primarily on building new units. The NHPD made clear that we were also quietly losing existing affordable homes as subsidy agreements expired or properties converted to market rate.”
By grounding conversations in data, the database helped advance a more complete strategy, one that balances new development with preservation.
Turning insight into action
Today, the NHPD is central to The Housing Collective’s preservation work. Wells mentioned that the team uses the database to map subsidized housing across Connecticut and identify where affordability restrictions may expire in the coming years.
“This allows us to understand where preservation risk is concentrated and where early intervention could make the greatest impact,” Wells explained.
From there, the data becomes a starting point. The team layers in local knowledge from housing authorities, nonprofit developers, municipalities, and community organizations to better understand property conditions, ownership dynamics, and potential preservation opportunities. This approach helps move preservation efforts from reactive to proactive, identifying risks early and exploring strategies before affordability is lost.
Supporting policy and planning decisions
Beyond project-level insights, the NHPD also plays an important role in shaping broader housing conversations. Wells noted the database's value when discussing housing policy.
“The NHPD has been especially valuable in helping policymakers and stakeholders understand the scale of preservation risk in Connecticut and why preservation must be treated as a core housing policy strategy rather than an afterthought," she said.
The data has supported discussions with state leaders, funders, and housing advocates, and informed broader planning efforts, including work conducted with the Urban Institute to develop a roadmap for addressing housing affordability in Connecticut.
Advice for organizations getting started
For organizations new to the database, Wells recommends starting with the data as a way to build understanding and alignment.
“Start by using the database as a conversation tool," Well said. "The NHPD allows organizations to quickly understand the subsidized housing landscape in their region and identify where affordability restrictions may expire in the future. Production, preservation, and tenant protections all need to work together. The NHPD provides an essential foundation for understanding where existing affordable homes are located and how communities can act early enough to preserve them.”
Moving from reactive to proactive preservation
As housing challenges continue to grow, tools like the NHPD are helping organizations take a more strategic approach. By identifying risk early, informing decision-making, and strengthening collaboration, data can help communities move from reacting to housing loss to proactively protecting the homes they already have.
Explore preservation risk in your community using the National Housing Preservation Database and related tools to better understand your local housing landscape.
