The two men are looking for more than sturdy structures or household amenities; they are out to catch real estate companies selling homes with illegally converted apartments.

It has worked with tenant associations involved in negotiations with landlords about converting rented apartments to co-ops.

In addition, the group called on the city to convert private-market apartments, currently used as emergency shelters, to permanent housing.

The company is also converting two interconnecting, 1920's commercial buildings at 57 Front Street to 33 one- and two-bedroom rental apartments.

Gardiner also announced in late 1992 that the city would lift a five-year moratorium on converting apartments into condominiums.

Some landlords, though, break the law so overtly that illegally converted apartments have become their trademark.

Nail realized that most of these new arrivals were not financially able to purchase homes, and began converting or constructing apartments on his land purchases.

In 1993, the foundation converted apartments adjacent to the museum into a garden annex, a shop and more galleries.

What Lisl called "the flashy new American hotel" was really three Berlin town houses tastefully converted into unobtrusive "residential apartments."

Mr. Wein said the department has made it easier to convert apartments legally, and even allows landlords to apply on line, but illegal conversions remain a problem.