The Paul Martin Sr. Building is a 5-storey Art deco lowrise office building in downtown Windsor, Ontario, located on the west side of Ouellette Avenue between Chatham St and Pitt St. It is named after Paul Martin Sr., father of former Prime Minister of Canada, Paul Martin. The building is also known by its French name "Edifice Paul Martin" and was at one time nicknamed the "Post Office Building" because it once housed the Canada Post office. The Canada Post office was relocated to a new location down the street around 1994. The building houses the Canada Revenue Agency and Canada Border Services Agency, in addition to a Canada Post depot and dock which remain after the public post office moved from the front portion of the building. The building was renamed on November 18, 1994. Currently, the building's limestone façade is in very poor condition and contains many chips and cracks visible from the street. For this reason, the building has had scaffolding around the three street facing sides since 2009 to protect pedestrians from the threat of falling stone.