• NYC 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 puzzle

A 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 about 10,000 of the 15,000 plots in NYC's portfolio are currently zoned for residential use. A third of city-owned lots are overseen by the Department of Parks and Recreation, suggesting they may already be in use as parks, open public spaces, or sports facilities.

Buildable space is also a consideration. Krimmel said a very limited number of vacant lots in the city clear both the size and zoning bar for housing. That means the city will need to get creative with existing developments; Krimmel suggests stacking housing on top of civic buildings where possible.

He added that a public land construction push won't solve all of NYC's housing woes, but "if you're trying to make good policies, you need to leave no stone unturned." The city turning to existing public land is a great idea, he said, though selling it to developers for affordable housing use could be another financially-smart option.

"The city has valuable assets on its books," Krimmel said. "The question is whether it deploys them by building itself or whether it attaches affordability requirements, upzones, and lets other developers carry the financing and operations."

To reach its goal of 200,000 new affordable units, the Mamdani administration will also need support and resources from City Council, Albany, private developers, and taxpayers. As my colleague Juliana Kaplan reported, part of the reason New York is so expensive is it's a desirable place to live — which is unlikely to change anytime soon.

The Mayor's Office hopes its proposed rent freeze, universal 2-K childcare program, fast and free bus pitch, and other affordability initiatives will help lower New Yorkers' cost of living in the meantime. These initiatives go hand-in-hand with housing access, the mayor said.

As he told a crowd in Queens last month: "We will no longer speak in the language of promise. We will speak in the language of the present. We will build more homes."

Bernie Sinclaire calls herself a "mommunist."

For nearly two years, the 38-year-old has raised kids with her best friend in their shared Manhattan apartment — and she couldn't recommend the setup more. She and Anabelle Gonzalez, 39, have a household rhythm: they trade off chores, cooking, and doing crafts with their elementary-age children. Better yet, the pair splits bills in one of America's most expensive cities.

"We'll be laughing on the couch, playing with our kids, and dinner is made, and the kitchen is cleaned," Sinclaire told Business Insider. "It's been mind-blowing to be able to just sit and talk. That was not something that I experienced when I was in a relationship, and it was not something I was able to enjoy as much when I was a single mother."

In a city where paychecks are stretched thin and monthly daycare costs rival rent expenses, New Yorkers are pinching pennies. A recent report from the Mayor's Office found that it costs the average family $159,000 to live and raise children in the five boroughs, and that's just for basics like housing and healthcare. Sixty-two percent of all residents — and the vast majority of single-parent households — don't earn enough to meet their cost-of-living threshold. It's hardest for mothers, who are often paid less than men and shoulder more childcare responsibilities.

New York City Mayor Zohran Mamdani took office with a mandate to make the city more affordable. He has announced a plan for universal childcare for toddlers and preschoolers, which builds on the existing NYC Public School free 3-K program. Other proposals aim to lower the cost of apartments, buses, and food. It's a big task, especially as the city's housing demand continues to outpace supply.

To make ends meet, Sinclaire and Gonzalez became a dual-income household with a combined $200,000 — and really fun wallpaper.

"This is not the Mojo Dojo Casa House," Sinclaire said, referring to Ken's bachelor pad in the "Barbie" movie. "This is the Barbie Dream House."

'A utopia'

The concept of a "mommune," or commune of moms, has always made sense to Sinclaire. She was raised in Italy by a single parent, and said she watched her mother have to "choose between poverty and partnership." She wanted to avoid being financially dependent on a man.

"That was a dream and a wish from early on: to create a family not centered on male partnership and not centered on romance," she said. "Friendships are way more long-lasting, and it didn't make sense to me to have my children's welfare and financial security hinge on something that data shows over and over again is not really working for most women."

Sinclaire and Gonzalez met at an NYC graduate school in 2013 and stayed in touch when they became mothers. Sinclaire has two sons, ages 4 and 9, and Gonzalez has a 7-year-old daughter. Gonzalez had divorced when Sinclaire pitched moving in together.

"It took me time to process because you don't really hear about that type of alternative family," said Gonzalez, who grew up in Brooklyn. She didn't agree right away. "At first I was like, 'Okay, girlie, I love you, but what are you talking about? Then I cried at the end of the conversation because it sounded like a utopia."

The pair initially settled into Sinclaire's existing two-bedroom apartment, then upgraded to a three-bedroom, two-bathroom Harlem unit costing $4,550 a month. Their monthly rent is roughly $600 higher in the new place, but they say the space is essential as their kids grow. Their two incomes allow them to stay local. In upper Manhattan, about 52% of renter households spend 30% or more of their income on housing, the threshold housing economists typically define as unaffordable.

Both women teach at the same public high school, and said their finances have become more stable since they began sharing costs. Last year, Sinclaire earned $94,278 after deductions and Gonzalez earned $106,952, tax documents reviewed by Business Insider show. They split the $600 monthly grocery bill 50/50, then Gonzalez covers WiFi, and Sinclaire pays the electricity bill.

Childcare is divided, too. Sinclaire's youngest son is now old enough for free 3-K (which saves over $1,000 each month), and the others are in public school. The two moms trade drop-offs, pick-ups, and watching the kids. When there's a gap, they call their part-time caregiver. "She's been with us forever," Sinclaire said. "And we don't have as many hours for her as we did before, but she's our lifeline." Their monthly childcare costs average $600, with Sinclaire paying a larger share because she has two kids.

Since starting the "mommune," Sinclaire said she saves about $1,200 more each month, which goes to her emergency fund, retirement, and kids' college accounts. Gonzalez said they also spend less on takeout and impulse purchases because they can split household responsibilities and avoid burnout — something that wasn't the case in either of their previous relationships. That time and energy savings can't be overstated, she said.

"You want to be honest about your soul and boundaries and your lifestyle up front," Gonzales said. "Talking about money is uncomfortable — and it has been uncomfortable for me and for Bernie because it was the first time we, as friends, were talking about it — but it's important to talk and be honest about money."

'A New Yorker forever'

Gonzalez is the first to wake each morning to start breakfast. "I don't do measurements," she said, but each plate turns out delicious anyway. Sinclaire — a recipe loyalist — prefers cooking dinner.

Their children act like siblings and enjoy playing together, with occasional squabbles. The moms are each other's support system, and treat all three kids like their own.

"I think that if you're blessed to have a big community, you might not see this as something very different," Sinclaire said. "But if you are, like many mothers, 'default parenting,' and you're overwhelmed and you've lost your sense of self, friendship is lifesaving."'

Sharing a life has given the two more space for their creativity. Gonzalez co-owns a clothing brand. Sinclaire has been able to spend more time on art and is turning years of handwritten journals into a book. Saving money has also given the family more resources to travel. They took the kids to Mexico recently and plan to take their "first solo mommy trip" to Turks and Caicos this summer.

The pair hasn't sworn off romance, but they wouldn't trade it for the "mommune."

"A lot of times people are like, 'This is crazy, that you're going to move in with another woman,'" Sinclaire laughed. "And I said, 'How is that more crazy than moving in with a man that you met online and having children with him?'"

"Yes, we do date," Gonzalez added. "But anybody who dates people will understand that you live in your house and I live in mine."

Even when the kids get older and move away, the moms don't think they'll part ways. There are simply too many Jon Hamm TV shows, Cardi B albums, and nightlife spots for them to appreciate together. They see the "mommune" lasting long past their child-rearing years.

Plus, rent isn't getting any cheaper, and neither of them wants to leave NYC.

"I'm a New Yorker forever," Gonzalez said. "I love my city."