In November last year, Mayor Bill de Blasio revealed an ambitious update to his affordable housing agenda. As part of Housing New York 2.0, the mayor wanted to create and preserve 300,000 units of affordable housing by 2026, up from his previous goal of 200,000 units by 2024.

That’s just one aspect of his affordable housing agenda; another aspect is greater transparency, not just in showing how many affordable units exist across the city, but what neighborhoods they’re located in, and how many units exist in each building.

To that effect, the city’s Department of Housing Preservation and Development has been working for the past 18 months to create a map that shows off all the affordable housing that has been created or preserved since Mayor Bill de Blasio first took office in 2014.

HPD staff spoke with Curbed last week and highlighted some of the functions of the map, which distinguishes between new units created (dark blue), and affordable units preserved (light blue). HPD used the purple house icons on the map in cases where they needed to protect the identity of the homeowners; these purple houses usually concern repairs on single-family homes or in some cases they are used to protect the identify of victims of abuse such as domestic violence survivors.

Via HPD

These purple icons reveal what community board that particular project falls under, and though there appear to be many purple icons, HPD staff informed Curbed that these units account for less than one percent of the total affordable units preserved and created citywide.

A key factor missing from the map is the length of affordability on each building or housing unit, but HPD staff clarified that the minimum length for any property was 15 years, and that the city had guaranteed much longer periods in most cases. This is also something they are looking to add to the map in the future.

All of the data on the map is first hand-entered by HPD staff into their system, and then verified by other staff members before it is uploaded to the map; as a result, the map will be updated once every quarter.

For the HPD, this map isn’t just a tool for affordable housing advocates and activists, but a tool all New Yorkers can use to understand the scope of affordable housing in the city. Head on over to HPD’s site to test out the map.