One new Manhattan skyscraper will greet residents of pricey condos with a lobby in front, while renters of affordable apartments that got the developer government incentives must use a separate side entrance — a so-called poor door.

In another apartment house, rent-regulated residents can't even pay to use a new gym that's free to their market-rate neighbors. Other buildings have added playrooms and roof decks off-limits to rent-stabilized tenants.

New York is a city where the rich and relatively poor have long lived side by side, with who pays what often a closely held, widely varying secret. But a recent spate of buildings with separate amenities for the haves and have-nots is hurling that question out in the open, provoking an uncomfortable debate over equality, economics and the tightness of the social fabric.

"Nobody treats me like a second-class citizen in my own home," says Jean Green Dorsey, who filed a complaint with the city Human Rights Commission this spring over her Manhattan building's fitness center. She and fellow rent-stabilized tenants aren't allowed to enter it despite a willingness to pay a fee; market-rate renters use it gratis.

Developers say they're motivated by business, not bias, and reserving some prime features for higher-paying residents is the price of having affordable housing in hot neighborhoods.

But officials are broaching proposals to force more inclusiveness, troubled by seeing landlords use affordable-housing tax and zoning breaks to create what critics view as a caste system.

In a city where Mayor Bill de Blasio was elected last year on pledges to increase affordable housing and shrink income inequality, an outcry erupted after his housing department signed off last month on the affordable bona fides of the Manhattan poor door building; the project was approved and started construction before de Blasio took office. Its creator, Extell Development Co., declined to comment.

"We believe there should be a much more equal approach to all residents," said de Blasio, who as a councilman voted for the 2009 zoning code change that allowed such arrangements but says the "nuances" of different doors weren't evident then.

His administration is taking a sweeping look at affordable housing programs. Meanwhile, Manhattan Borough President Gale Brewer and other officials are clamoring to change the zoning code to end separate-door layouts. State Assemblywoman Linda Rosenthal wants to require landlords to offer amenities to all tenants, with provisions for reasonable fees. Councilmen Mark Levine and Corey Johnson are also drafting a proposal to add "class of renter" to the city's antidiscrimination laws.

To critics, treating rent-regulated residents differently sends a galling separate-and-unequal message. But developers say there can be financial and legal reasons for some separation.

Green Dorsey's landlord, Stonehenge Partners Inc., has said in a rights-commission filing that its gym policy is "an inducement to rent" market-rate apartments, noting that stabilized tenants get valuable plums of their own — like lower rent.

And fairly or not, apartment hunters may hesitate to buy an expensive place on the same floor as renters who don't have the same legal obligations, or means, to contribute to a building's ongoing expenses, said Steven Spinola, president of the Real Estate Board of New York, a major developers' and landlords' group. Even if doors are different, such buildings make for a mixed-income block, he noted.

"I would think that would be regarded as a significant accomplishment," Spinola said.

Hundreds of affordable apartments are sprinkled through one sleek Manhattan rental development's two towers, their lobbies nestled in an interior courtyard. But an adjoining, smaller building with 80 other affordable units has a door facing a bus depot.

"I'm very grateful to be able to live here," said one tenant in that building, speaking to The Associated Press on condition of anonymity for fear of angering his landlord. Tenants do share such features as a shuttle bus to transit lines, but he feels the separation "creates a real class tension."

The landlord declined to comment.

Some market-rate residents say separate lobbies and amenities are about sharing expenses, not creating social distance.

In Courtney Harding's glassy condo tower in Brooklyn's Williamsburg neighborhood, owners pay as much as $1,000 a month on top of their mortgages to maintain the building and its services, she said. The common charges don't apply to renters in the low-rise, brick affordable companion building next door.

"If you're not paying the doorman's salary, is it fair for you to use the doorman?" said Harding, who feels tenants should have an option to pay fees to use amenities.

Boleslaw Wisniewski is one of those tenants, and he's fine with the way things are. His new, $700-a-month studio is about a quarter the neighborhood's going rate.

"The deal is very good," says Wisniewski, who doesn't think twice about the condo dwellers above him. "The glass building, it's a completely different building."