sentences:  At 30 floors it and two other structures hold the title of the tallest building in the federally designated Central Park West Historic District.The height of the buildings were shaped primarily by the Multiple Dwelling Act of 1929 which allowed apartment buildings no higher than 19 stories.The law provided an exclusion for taller buildings, such as the Century, if a building site was sufficiently large and the building itself occupied no more than 20% of the site.