While most of the projects mix market-rate housing with lower-cost units, some contain only the latter.

The lower-cost units must be reserved for low- and moderate-income buyers for 10 years.

Market-rate rents will be about $1,800 to $3,000 a month, he said, adding that the lower-cost units would rent for $1,200 a month.

Judge O'Hagan ultimately determined that the borough was required to provide 146 lower-cost units.

Under pressure from community groups, it adopted inclusionary zoning provisions under which developers can build at higher densities if they include some percentage of lower-cost units.

So far, a special master has decreed that the project include 285 to 300 lower-cost units.

Where wetlands or other site constraints are present, the regulations reduce the number of lower-cost units by a third.

Or should it be sold to private developers who will build market-rate housing, with the proceeds from the sale used to subsidize lower-cost units elsewhere in the city?

The new plan would require that the lower-cost units remain permanently affordable to lower- and middle-income tenants, even after the tax break expires.

Thus, the survey concluded, by building one new market rate apartment, at least two lower-cost units became available for rent.