The California Housing Partnership (“the Partnership”) maintains a number of databases that help us achieve our mission of protecting and building affordable housing for low-income Californians. These databases include:

  • Affordable Housing Preservation Database
  • Unsubsidized Affordable Housing (UAH) Database
  • Housing Needs Dashboard Database
  • Affordable Housing Benefits and Mapping Database

Data Access Policy
Consistent with our mission, the Partnership can provide data to nonprofit organizations committed to preserving and creating affordable housing, academic researchers conducting projects connected to our mission, government agencies, and verified consultants working with public agencies. The Partnership does not provide data to real estate agents/brokers or any entity not clearly committed to preserving affordable housing or respecting our prohibition against the resale or re-use of our data. Requests for any full statewide datasets will not be accepted in the vast majority of cases.

Data Use Agreement
A Data Use Agreement (DUA) must be executed prior to data being sent to the requestor. For all types of data requests that have a cost associated with them, the requesting party will receive an invoice from us that details the total number of hours and cost given the complexity of the request, the geographic extent of the data being requested (all counties, some of the counties, cities within a region, one city, etc.), and other factors that may impact total staff time dedicated to the request. If payment is required for a data request, the requested data will be emailed to the requesting party once a DUA has been executed and payment is received.

The following sections outline the policies for accessing data from each of our databases:

Preservation Database
The Partnership maintains data on properties with HUD subsidized mortgages and/or Section 8 contracts, USDA Section 514 and 515 rural properties, HCD, CalHFA, properties with Low Income Housing Tax Credits, and local restrictions or assistance. Please note that the Partnership does not represent that its data is complete or accurate beyond what we can obtain from our sources.

  • The Partnership receives quarterly updates from the Regional HUD office for the approximately 1,800 HUD-subsidized properties in California. These updates include the following data fields: property name and address; total number of units and total number of Section 8 units; owner and management contact information (when available); mortgage type, original amount, maturity date and unpaid balance; Section 8 contract start and end date and renewal information; and any prepayment or opt-out requests.
  • Data on active USDA Section 514 and 514 properties in California is updated by USDA and includes: property name and address; mortgage type and payoff date, and original amount; total number of units and total number of Section 521 units; borrower name, management company name, and restrictive clause expiration date; prepay eligibility and date; and USDA estimated property exit year.
  • Low Income Housing Tax Credit properties are updated annually based on data received from the California Tax Credit Allocation Committee and include: property name and address; total number of units and total number of low income units and size of units; population served, placed in service date, and income groups served (when available); owner and management company information, and application date; and year the regulatory agreement ends (when available).
  • Data on active CalHFA properties in California is provided by CalHFA and includes: property name and address; loan type, start and end date, and original amount; total number of units; placed in service date; regulatory end date; and sponsor name.
  • Data on active HCD properties in California is provided by HCD and includes: property name and address; loan/grant type; end date; total number of units; regulatory end date; income group served; and borrower/sponsor/general partner name.
      • Data on active locally restricted or assisted properties are gathered from publicly available reports that are provided directly by jurisdictions and includes: property name and address; regulatory end date; and number of units.1

Preservation Data Request Costs

  • Free of charge (assuming standard data requests):
    • Local Government Housing Agencies2
    • California Government Agencies
    • Nonprofits with a Substantial Contract3with the Partnership
  • Payment required ($200 per hour4):
    • For-Profit organizations working for a government agency5
    • Nonprofits without a substantial contract with the Partnership:
    • Academic researchers

Unsubsidized Affordable Housing Database
The Partnership maintains data on privately-owned and unsubsidized multifamily (5+ unit) rental properties, where due to some combination of the location and condition of the building, rents are affordable to low-income households. These properties are also referred to as Unsubsidized Affordable Housing (UAH) or “naturally occurring” affordable housing (NOAH). Using a proprietary methodology, the Partnership identifies UAH properties utilizing CoStar data on 5+ unit properties across the state, including UAH properties that have lost affordability and UAH properties that are at-risk of losing affordability. UAH properties are defined as: apartment buildings with five or more units (which is the state’s definition of multifamily housing) where at least half of the apartments have rents affordable to households earning 80% of the median income for that zipcode. Please review our report, the California Unsubsidized Affordable Homes At-Risk Report 2025, for a more thorough understanding of the UAH database.

UAH Data Request Costs

  • Aggregated Data
    • $150 per hour6
      • An estimate of the total number of hours and cost will be sent to the requestor once we have an idea of the what data is being requested from the preservation database, the complexity of the request, and geographic extent of the data being requested (all counties, some of the counties, cities within a region, one city, etc.). Aggregated data is available at the census tract-level and above.
      • All entities requesting aggregated UAH data must pay for access to this database7. This includes but is not limited to
        • Local Government Agencies
        • California Government Agencies
        • Nonprofits
        • Academic researchers
        • For-Profit consultants working for a government agency
  • Property-Level Data:
    • $200 per hour8
      • An estimate of the total number of hours and cost will be sent to the requestor once we have an idea of the what data is being requested from the preservation database, the complexity of the request, and geographic extent of the data being requested (all counties, some of the counties, cities within a region, one city, etc.)
    • Property-level data can only be requested by a mission-driven nonprofits with a current CoStar license for the staff person accessing the data. Costs vary based on request complexity due to additional staff time and resources needed to fulfill these types of data requests.
      • To avoid violating CoStar’s terms of service, we will not share property-level data from our UAH database with a public entity given the risk of FOIAs or with a non-profit organization that doesn’t have a staff member with a confirmed CoStar license.

Housing Needs Dashboard Database

The Partnership’s Housing Needs Dashboard (“Dashboard”) is an interactive tool showcasing data on the state of housing in communities across California, including housing need, market trends, funding, and production and preservation trends. If you would like to learn more about the data sources, data analysis, and charts in the Dashboard, please review the Methodology document found on our website.

Housing Needs Dashboard Data Request Costs

  • We encourage entities or individuals, where possible, to utilize the dashboard to extract the data they need for their project, but if the requestor would like the Partnership staff to compile and send them the underlying data of the data tool the following costs will apply:
    • $150 per hour9
      • An estimate of the total number of hour and cost will be sent to the requestor once we have an idea of the what data is being requested from the preservation database, the complexity of the request, and geographic extent of the data being requested (all counties, some of the counties, cities within a region, one city, etc.)
    • All entities10 requesting Housing Needs Dashboard Data must pay for access to this database. This includes but is not limited to
      • Local Government Agencies
      • California Government Agencies
      • Nonprofits
      • Academic researchers
      • For-Profit consultants working for a government agency

Affordable Housing Map and Benefits Calculator Database

The Partnership’s Affordable Housing Map and Benefits Calculator (“AH Benefits Map”) uses the California Housing Partnership’s Preservation Database—an inventory of federally and state-subsidized affordable rental properties, many of which also receive local subsidies—and leverages academic research on the social and economic benefits of affordable housing to provide an interactive web-based map. If you would like to learn more about the data sources, data analysis, and charts in the AH Benefits Map, please review the Methodology document found on our website.

Please note the underlying property-level data for AH Benefits Map is derived from the Partnership’s preservation database, so if you are wanting to request the property level data displayed in this data tool please refer to the Preservation Database section of this document.

Affordable Housing Map and Benefits Calculator Database Request Costs

  • We encourage entities or individuals, where possible, to utilize the dashboard to extract the data they need for their project, but if the requestor would like the Partnership staff to compile and send them the data the follow costs will apply:
    • $150 per hour11
      • An estimate of the total number of hour and cost will be sent to the requestor once we have an idea of the what data is being requested from the preservation database, the complexity of the request, and geographic extent of the data being requested (all counties, some of the counties, cities within a region, one city, etc.)
    • All entities requesting Housing Needs Dashboard Data must pay for access to this database. This includes but is not limited to
      • Local Government Agencies
      • California Government Agencies
      • Nonprofits
      • Academic researchers
      • For-Profit consultants working for a government agency

1 Locally restricted affordable housing covenant data is unavailable for the majority of properties in the Preservation data.

2 Local government housing agencies complying with their obligations under state law to track existing affordable housing and their verified consultants.

3 Nonprofit or local government organizations that currently have a substantial services contract with the Partnership (or have a clear commitment to enter into a substantial contract with the Partnership).

4 Please note the cost per hour range is reflective of staff time and resources needed to review data requests, communicate/meet with requestor to understand what data is being requested and why, create and send data file to requestor, and respond to potential questions from requestors once data has been sent. The final cost per hour for staff to fulfill a request will be discussed with the requestor once the Partnership learns more about the complexity and extent of the request.

5 The Partnership does not provide data to real estate agents/brokers or any entity not clearly committed to preserving affordable housing or respecting our prohibition against the resale or re-use of our data.

6 Please note the estimated cost per hour is reflective of staff time and resources needed to review data requests, communicate/meet with requestor to understand what data is being requested and why, create and send data file to requestor, and respond to potential questions from requestors once data has been sent. The final cost per hour for staff to fulfill a request will be discussed with the requestor once the Partnership learns more about the complexity and extent of the request.

7 If the project being conducted is deemed to be mission aligned, the fee for the aggregated UAH data could be waived.

8 Please note the estimated cost per hour is reflective of staff time and resources needed to review data requests, communicate/meet with requestor to understand what data is being requested and why, create and send data file to requestor, and respond to potential questions from requestors once data has been sent. The final cost per hour for staff to fulfill a request will be discussed with the requestor once the Partnership learns more about the complexity and extent of the request.

9 Please note the cost per hour range is reflective of staff time and resources needed to review data requests, communicate/meet with requestor to understand what data is being requested and why, create and send data file to requestor, and respond to potential questions from requestors once data has been sent. The final cost per hour for staff to fulfill a request will be discussed with the requestor once the Partnership learns more about the complexity and extent of the request.

10 News organizations requesting data from the Housing Needs Dashboard would not have to pay a fee.

11 Please note the cost per hour range is reflective of staff time and resources needed to review data requests, communicate/meet with requestor to understand what data is being requested and why, create and send data file to requestor, and respond to potential questions from requestors once data has been sent. The final cost per hour for staff to fulfill a request will be discussed with the requestor once the Partnership learns more about the complexity and extent of the request.