Ed Reed/Mayoral Photography Office

De Blasio's ambitious housing plan has spurred its own concerns about affordability -- namely whether housing subsidies linked to income levels that are out of step with city neighborhoods will trigger their own wave of displacement.

Mayor de Blasio on Monday hailed what he called “the very best year ever” for affordable housing in New York City, announcing that during the fiscal year that ended in June the city built or preserved 20,325 units of affordable housing.

A City Hall press release said that number was “the most in 25 years” and added that the city “broke an all-time record for the most new affordable apartments underway – nearly 8,500 – the highest figure since the City’s Department of Housing Preservation and Development was established in 1978.” The work had a price-tag of $618 million.

Three of New York City’s past five mayors have committed their administrations to producing large amounts of affordable housing. Ed Koch launched his Ten-Year Plan, which aimed for 252,000 units, in 1985. Mike Bloomberg rolled out his 165,000-unit New Housing Marketplace program in stages over his first five years in office. De Blasio, the only one of the three who was elected on a pledge to address inequality and affordability in the city, in May 2014 set a target of building or preserving 200,000 units over 10 years. With 2,700 units completed during the last half of fiscal 2014, the current administration is more than 10 percent of the way to its goal.

Increasingly, however, some have worried that a narrow focus on producing or preserving a headline-friendly number of units could undermine the deeper purpose of the de Blasio program, which is to permit lower- and middle-income New Yorkers from being driven out of their neighborhoods or the city.

“We appreciate that the de Blasio administration is focused on increasing affordable housing, but today’s announcement was a premature victory lap,” said Maritza Silva-Farrell, a spokeswoman for Real Affordability for All. “The de Blasio administration should focus on achieving much deeper levels of real affordability in housing, especially in neighborhoods that will be rezoned. Affordable for whom is still the question many New Yorkers ask about the city’s housing plan, particularly those residents who may be exposed to the worst effects of gentrification and displacement through the rezoning process.”

De Blasio addressed critics of his housing policy in remarks he made Monday at an affordable-housing site in the Bronx.

“Now, many people say, ‘What is affordable?'” the mayor said. “This building will be affordable to families that make between $23,000 and $46,000 a year for a family of three – $23,000 and $46,000 a year. That’s a lot of people in this city. That’s a lot of people who are at the lower side of the income level and need help and need affordable units. This is going to reach them. “

The Association for Neighborhood Housing Development (ANHD), which has been critical of de Blasio at times, gave City Hall a gentle slap on the back. “What has become clear in this first year of the plan is that the administration’s dedication and commitment are equal to the task,” noting the recent rent-freeze and de Blasio’s increased support for NYCHA. ANHD did note that, among other things, “the administration needs to redouble its efforts on producing units for the lowest income New Yorkers, where the housing crisis and rent burden is greatest.”

“But overall the de Blasio administration is off to an extremely commendable start.”