Mayor Bloomberg yesterday announced that the city has reached a deal to sell the former Board of Education headquarters building at 110 Livingston St. to a private developer. The deal will bring Downtown Brooklyn 245 new condominium housing units, and it will bring the city $45 million, according to a press release from Mr. Bloomberg’s office. It’s a step in the right direction for the city, which seems constantly to be building and renting more space for its enormous workforce, rather than reducing the size of the workforce and selling off space. Other watershed moments in the privatization of city real estate will come tomorrow from 1 p.m. to 2 p.m. at 80 State St. in Brooklyn Heights, when the city-owned townhouse where the schools chancellor used to live will be available for viewing by potential bidders. And on July 23, when the town house is scheduled to be sold at auction. Mr. Bloomberg deserves credit for taking these bold steps, which are a creative way to raise cash for the city and which send a message that change is afoot at the highest level of the city’s public school administration. There’s plenty of more work ahead for the mayor, both on the school administration front and on the matter of privatizing city property. Gracie Mansion would be a fine next step. And we have our problems with the demand on the private developer at 110 Livingston St. to include as part of the deal “affordable” housing, by which the city means housing at below-market rates for a lucky few who are subsidized by the rest of us who pay market rates. But overall, with the sales of 110 Livingston St. and 80 State St., Mr. Bloomberg is setting a standard worth pursing in the coming months and years.