As rents rise throughout the city, the number of apartments for working-class and poor New Yorkers has declined by 20 percent since 1993, according to a startling preview of the most recent Housing and Vacancy Survey.

The survey, which is produced every three years by the federal census bureau, shows that rents are up, renters incomes are down, and that the number of rent-controlled units in the city are plummeting as elderly tenants die or leave them.

But it is the general rise in rents–and the proliferation of luxury units–that is the dominant theme of the preliminary summary of the survey released last week. Since 1993 years, there are 112,000 fewer apartments in New York City renting for less than $500 per month. The total number of such units has free-fallen to 451,741, even as federal rent subsidies and the city commitment to subsidizing rehabs decline sharply.

“It reinforces everything we have been hearing anecdotally out in communities for the past few years,” said Victor Bach, a housing policy researcher for the Community Service Society. “We need to do something to assure that low-income people aren’t forced out of the housing market by rent inflation.”

Overall, the housing vacancy rate in the city is higher now than at any time in the 1990’s–around 4 percent of all rental apartments–although many of the vacant units are too expensive for working-class families to afford. Experts believe that the increased vacancy rate may be a simple result of higher rents and lower incomes. New York State’s rent regulations automatically expire if the vacancy rate exceeds 5 percent.

A full analysis of the survey is not expected for at least a year.

Some more key findings:

A 30 percent drop in the number of rent controlled units, down from 102,000 in 1993 to -70,500 in 1996.
The median rent of all units has increased by 18 percent since 1993 to $593. Meanwhile, the median income of renter households–about $20,000–is about 3 percent lower than in 1993, adjusted for inflation.
There has been a boom in the luxury end of the market, with the number of apartments renting for $1,500 or more growing from 49,000 to 55,700.