The apartment building under construction at 975 Nostrand Avenue in Brooklyn is the kind of project that city officials and economists say New York needs to solve the city’s severe housing shortage.

It will have 328 new homes at rents targeting young professionals, from studios up to three-bedrooms, with a grocery store on the ground floor.

But the ability to construct these homes, at this location, turns on a peculiar problem: How do you also find a place to park 193 cars on this lot?

This Brooklyn building is subject to a powerful but obscure force operating in communities all over the country: the parking minimum. Every one of its 193 parking spaces is prescribed by the city’s zoning code, in dizzying detail.

The project must provide, at minimum, half a parking spot for each housing unit; one parking spot for every 400 square feet of retail and art gallery inside; and one spot for every 300 square feet of space in part of the planned grocery store (the other part of the grocery store is exempt from parking, and we’re sorry but only a land use lawyer can explain this).

New York is now proposing to radically simplify requirements like this by ending parking mandates on all new housing citywide. The move could make it cheaper and faster to construct new homes amid a housing affordability crisis, and it would make New York the latest American city to toss out decades-old parking rules. But as a movement to end parking minimums gains traction across the country, what happens in New York will be revealing: In the least car-dependent big city in America, the instinct to accommodate cars may still prove stronger than fears about the shortage of homes.

“These rules were written at a time when cars defined everything,” said Dan Garodnick, the head of New York’s Planning Commission.

It was a moment when cities were first racing to adapt to cars and compete with suburbs full of plentiful parking. “We are in a different era today,” he said.

That assessment will be put to the test in the coming weeks, as the City Council is set to vote on the change as part of a broader package of housing measures.

Mr. Garodnick is quick to clarify that the administration is not proposing to end parking in residential buildings — just the required minimums. Developers will still build parking, he reasons, where there’s demand for it (and in fact, today some build more than the minimum). But they’ll also have the option to build none.

Those opposed to the change are skeptical of its benefits: “I don’t see where less parking means there’s greater affordability,” said Fred Baptiste, the chair of Community Board 9, where 975 Nostrand sits. “It just means there’s less parking.”

Six Parking Spots Per Bowling Lane

Cities and towns nationwide have had parking minimums sitting unquestioned in their zoning codes for half a century. But in recent years, dozens of cities have removed them. Buffalo was among the first in 2017. Austin, Texas, last year became the largest U.S. city to do so.

As housing has grown more expensive across the country, cities have increasingly realized that parking can make the problem worse, raising the cost and complexity of development, even discouraging the construction of homes.

Construction costs run from $10,000 per parking space in a surface lot to $70,000 per space in an underground garage. That gets baked into what developers must recoup from tenants and buyers, whether they own a car or not. The rules drive up the per-unit cost to build affordable housing (in New York, affordable units near transit are exempt from parking minimums, but the rules still apply elsewhere). And they often require more parking than people actually use.

The mandates began in the 1950s and ’60s as mass car ownership expanded beyond the capacity of on-street parking. Minimums in New York were introduced in 1950 for new residential buildings. The city’s 1961 zoning code (the one still in place today) raised the requirements and added them for offices, retail and other building types. In New York and elsewhere, the rules typically take the form of ratios that have been copied from one city to another, handed from one generation of engineers to the next without much study or skepticism.

“People just assume these numbers are right because they’re in the zoning code,” said Tony Jordan, who runs the Parking Reform Network, which advocates ending minimums. “No, they’re just made up.”

Beyond increasing construction costs, the rules have squeezed out of existence many common prewar urban housing forms, like four-unit apartment buildings on lots too small for parking. Mandates have meanwhile produced their own specific kinds of places: stores surrounded by surface lots, strip malls wrapped around parking, apartment complexes that have no ground-floor retail because the ground floor is full of cars.

And because the rules apply broadly, they can require parking in subsidized housing for low-income households least likely to own a car. They can force builders to construct 350 square feet of garage space for a 400-square-foot studio.

Given that cities have only recently begun to change these rules, there’s limited evidence of what happens after they’re gone. In the first years after Buffalo ended parking minimums, about half of new developments built fewer parking spaces than they were previously required to, supporting the idea that the standards are too high for some properties, too low for others.

Proponents also hope that by ditching parking mandates, cities communicate another message: “If you require a place to park a car, you’re automatically saying a car is welcome,” said Felicity Maxwell, a planning commissioner in Austin who voted to end minimums there last year. And many of the prewar buildings and neighborhoods cherished today are places that have long thrived without welcoming cars.

Compared with Austin and Buffalo, New York is proposing a half-measure: to end mandates only for housing (at 975 Nostrand, for example, the retail space would still require some parking). Mr. Garodnick demurred on whether ending all minimums would be a logical future step for the city.

An Expensive Hole in the Ground

New York is also a particularly tough place to create parking. Land is so scarce and valuable that it seldom makes sense to use it just to park cars. 975 Nostrand was originally a single-story grocery store with a large parking lot. Now it will become home to 500 to 600 people, with a grocery store on the ground floor.

But making the best use of that limited space means developers frequently turn to the hardest possible parking solution: putting it underground.

“When you go below grade in New York City, you are talking about the most expensive and the most risky part of a project,” said Sam Charney, principal of the developer Charney Companies. His worst construction horror story involved a mixed-use building that required two levels of underground parking in a corner of bustling Williamsburg in Brooklyn. He thought the parking actually necessary was none.

Excavation is costly and onerous. Neighboring buildings must be underpinned. Buried oil tanks and boulders get in the way. Below the water table, everything must be waterproofed. And all of this adds months to construction, during which time developers are carrying large loans.

Parking stackers help save space by lifting cars up so others can park underneath. But then garages require parking attendants to operate them — and that’s another cost someone has to pay.

All of this is further complicated by the fact that the exact quantity of parking required depends on how the land at a given site is zoned.

Certain zones also exempt parking on the first five or 15 housing units, incentivizing builders to stay below that cutoff — or to carve lots up into several smaller buildings with fewer total housing units.

“You really don’t want to build a bigger building than you can provide parking for,” said David West, an architect.

These trade-offs for developers don’t garner a lot of sympathy with New Yorkers who have a more prosaic concern: where to park after a long work day or when there’s a hungry child in the back seat. The community board that encompasses the Nostrand development opposes getting rid of the minimums, as do politicians representing parts of the city that don’t have good transit access.

“For Staten Islanders, it’s almost impossible to not have at least one car per household,” said Joseph Borelli, who represents southern Staten Island as minority leader of the City Council.

The City Planning Commission expects that the greatest change to come from ending parking mandates would be in the “inner outer” boroughs — not in the lowest-density neighborhoods that have opposed it the most, but in places like Nostrand Avenue in Crown Heights. That’s where the gap is widest today between the quantity of parking required and the demand for it around public transit. In the densest parts of the city — much of Manhattan, and Long Island City in Queens — parking minimums are already waived (Manhattan, in fact, has had parking maximums since 1982, in a bid to reduce car travel and improve air quality).

Some suggest the city should more narrowly tailor its proposal rather than sweep away requirements citywide. But that would be an extension of what New York has done for years — carving out piecemeal exemptions for certain geographies, lot sizes, affordability levels and building amenities, until it has arrived at an intricate web of parking rules.

To proponents of ending minimums, the citywide simplicity is part of the point: The requirements aren’t just arbitrary near the subway; they are arbitrary everywhere because a prescribed ratio can never be just right for every lot. And even on Staten Island, lifting the minimums might allow someone to build an accessory dwelling unit — without extra parking — in the backyard. That would serve the city’s housing goals too.

At 975 Nostrand, where the developer Hudson Companies is about a year away from completing the building, the managing director of development, Marlee Busching-Truscott, struggled to estimate exactly how much parking would have been built if that number weren’t dictated by a zoning table. This is one of the other distortions of parking mandates. Developers typically try to study the market for nearly every facet of a project — the mix of apartment sizes, the targeted rents, the building amenities, the outdoor spaces, the kitchen finishes. But they don’t do that basic exercise for something as costly and sizable as a parking garage, because they have little choice in the matter.

Though Ms. Busching-Truscott couldn’t say exactly how the building would have taken shape without parking minimums, “I don’t think we would have gotten to 193 spaces that would have required having a fully excavated cellar and a chaotic layout.”

That result speaks to the building’s essential paradox: “This is transit-oriented development,” she said, “that you’re still building around the car.”