White House - official name of the executive mansion of the President of the United States. It is on the south side of Pennsylvania Ave., Washington, D.C., facing Lafayette Square. The building, constructed of Virginia freestone, is of simple and stately design. The porte-cochere on the north front, which forms the main entrance, is a portico of high Ionic columns reaching from the ground to the roof pediment; it is balanced by a semicircular colonnaded balcony on the south with a second-floo...