A flood of 311 calls complaining of housing code violations appears to be the work of home-improvement frauds.

Investigators took documents from the Manhattan office of Lehr Construction and also went to the Long Island home of one of the company’s executives.

The man, who was terminated by the city’s Buildings Department in 2007, was charged with selling safety-training certificates for workers who had not received any training.

Two executives of Testwell Laboratories, once New York’s top concrete testing company, were convicted of enterprise corruption in connection with the falsification of tests.

Investigators from the Buildings Department found illegally subdivided apartments in their canvas of the building in Bensonhurst that was badly damaged in a blaze last month.

Charges that the Builders Group directed the overbilling of clients in the New York area echo corruption cases of years past.

A study by Scott Stringer, Manhattan borough president, estimated that more than one-third of public school buildings in Manhattan have hazardous violations.

Nearly 100 hotels are scheduled to open in major American cities this year, when many hotels are having trouble filling their rooms.

A 333,000-square-foot dealership in Manhattan will have five levels, two of which will be above ground and have glass walls on three sides.

A developer is beginning a public review of a proposal for a $1.5 billion residential project, with 2,200 apartments in new buildings and in the old Domino Sugar refinery.