The Johnson Building at Boston Public Library, adjoining the historic 1895 Central Library, consists of seven above and two below grade floors. An unusual construction technique was used - starting the building from the bottom, then erecting the main columns and seventh floor trusses and proceeding from the top down. Renovations consist of system upgrades, three new individual libraries, opening entry to McKim building, two-story lobby space, small balcony to mezzanine, new stairs between mezzanine and first floor, and replacement glass at window openings between first and second floors.