Mamdani wants more housing on public land. A map shows where NYC is building now — and why 'it's not a silver bullet.'

Mostafa Bassim/Anadolu via Getty ImagesNYC Mayor Mamdani wants to build 200,000 new homes.Some of these new housing projects will be on land the city already owns.An economist told Business Insider that the plan may face funding hurdles, but would boost supply.

Zohran Mamdani is making a big bet on turning city-owned property into affordable housing.The New York City mayor plans to oversee the construction of 200,000 affordable homes across the five boroughs. It's a significant undertaking that will require new builds, hotel and office building conversions, and widespread rezoning.

To control costs and limit red tape, the Mamdani administration is encouraging new development on existing public land, like converting libraries into mixed-use buildings or building on unused parking lots. If successful, a supply boom could help lower-income New Yorkers access housing and put downward pressure on overall prices.The administration's goal is to identify public sites to support at least 25,000 new affordable housing units over 10 years.

Ten projects — which are likely to yield a few thousand apartments — are currently in planning and development stages.Building on city-owned property is "not a silver bullet," said Jake Krimmel, senior economist at Realtor.com.

But it's one lever City Hall can pull.City-owned land could be a piece of the affordable housing puzzleA majority of New Yorkers spend more than 30% of their income on housing, the threshold economists define as unaffordable. Business Insider has heard from single moms who moved in together to save on rent, parents who are making just above the threshold for benefits, and six-figure earners struggling to make ends meet.

The city owns and leases a staggering amount of land, but not all of it is suitable for housing. "A lot of the city-owned land is not necessarily the easiest thing to build on because of zoning rules or parcel sizes and shapes," Krimmel said.An analysis by the New York University Furman Center found that