Definition of "intrabuilding"

But those were substatutes of Ms. Hyams’s code for apartment life, which mostly celebrated and mandated intrabuilding socializing. Ms. Hyams, the doting owner of a gray poodle (“she wore it like a brooch,” said one neighbor), organized pet play dates on her floor.

2008 June 23, Susan Dominus, “Uniting Neighbors, in Fun and Sorrow”, in New York Times‎