Approximately 3,000 of the 20,000 affordable apartments the de Blasio administration preserved or built last year will be permanently affordable. View Full Caption DNAinfo/Rosa Goldensohn

CIVIC CENTER — Approximately 3,000 of the 20,000 affordable apartments the de Blasio administration preserved or built last year will be permanently affordable — leaving the rest to eventually become market rate — according to the city housing department.

The city created 3,031 new homes under its inclusionary housing program, which ensures they will remain permanently affordable, while the other 5,453 affordable units being built under the city's watch will transition to market-rate rentals in as soon as 30 years, officials said.

The remaining 11,000 or so already-built units that are being preserved by the de Blasio administration as affordable were slated to become market-rate units as a result of earlier mayors' affordable housing agreements — the same temporary conditions the de Blasio administration is now using, critics say.

The Association for Neighborhood & Housing Development calculated that 234,511 affordable apartments that are at risk of expiring before 2037. View Full Caption Association for Neighborhood & Housing Development

"They will tell you that they're interested in permanent affordability and good stewardship, but at the end of the day, policies speak louder than words," said Moses Gates, director of planning and community development for the Association for Neighborhood and Housing Development.

ANHD estimates that there are more than 234,000 affordable housing units at risk of expiring in NYC between 2017 and 2037.

Of those, almost 170,000 apartments were built with city subsidies between 1987 and 2007, according to ANHD.

In a policy paper released last week, Gates argued that all new units created by the de Blasio administration — or any administration — should be permanently affordable. He said this administration has showered private developers with subsidies for time-limited agreements, perpetuating a costly cycle of expiration and preservation.

Housing programs like the ones de Blasio's team currently uses rely on tax credits and other incentives to convince private, for-profit developers to charge rents deemed affordable by government standards. Once agreements with those developers expire, the city must cut new subsidy deals to keep the housing affordable, known as preserving the units.

That means that in many neighborhoods that have gentrified since original agreements were signed, the city must now outbid an expensive rental market, according to Gates. As a result, HPD is now spending up to 30 percent of its housing subsidies towards preserving existing units, according to ANHD.

City HPD officials defended their affordable housing plan.

"The city’s new mandatory inclusionary housing program is focused on delivering permanently affordable housing to communities across the city. Because the land use changes we’re making are permanent, so is the affordable housing. And because of our financial analysis and enforcement tools, we can be sure those units won’t just be permanently affordable on paper, but in reality," HPD said in a statement.

The current administration has created far more permanent affordable housing than its predecessor. There were 858 more permanently affordable apartments created in 2015 alone than in the four prior years combined, according to HPD stats.

Mayor Bill de Blasio has vowed to amass 200,000 units of housing over the next 10 years, according to his plan, mostly by preserving affordable units about to go market rate.

In the last fiscal year, nearly 12,000 of the 20,326 affordable apartments the administration counted towards its program were preservations, versus newly constructed units. In fiscal year 2016, slightly more than 10,000 of the approximately 18,000 affordable units on deck will be preservations, according to city projections.

HPD said renewing expiring agreements at Mitchell-Lama and Koch-era developments is a "major focus of our housing plan."

"The only way to achieve permanent affordability through subsidy programs would be to make the subsidies themselves permanent," they said. "While no administration can or should promise permanent subsidies, what we can do is make sure we don’t let the thousands of apartments previous administrations have invested in expire, and extend their affordability for decades to come."

But Gates said permanently affordable housing need not involve "permanent subsidies."

"The only 'permanent subsidy' required under our model is a continuing tax exemption that would run concurrent with the affordability restrictions," he said of ANDH's proposals for permanently affordable housing. "It otherwise does not require any permanent or continuing subsidy."