To gain long-needed classroom space, Brearley School in New York City has entered into contract to buy an apartment building across the street from its current location. Of the 57 rental units in the building, 29 units remain occupied. The tenants have formed an association and have vowed to block the sale. The existing facility for the private K-12 girls school is stretched to capacity throughout the school day. It occupies a 12-story building (the top two floors were added in 1995) where five teachers in an academic department might share three desks in a converted broom closet as their office. The tiny upper-school library has about a dozen study carrels and a table that seats 10.