This commercial building, consisting of three separate units at 527, 529 and 531 Sussex Drive, was built between 1872-75. Francis McDougal, an important Ottawa businessman and politician (and Mayor of Ottawa from 1885-6) operated a hardware business at 531 Sussex as early as 1858. He redeveloped the site in 1872 into the current building with three separately owned units. The building continued to be used as a hardware and building supply store for nearly a century, and the adjacent units at 527 and 529 contained various shops and businesses and eventually government offices. In 1919-20, 529 Sussex Drive was leased to the Air Board, established to advise the government on aviation policy, and later on continued to be rented by the Department of Transport.
In 1964, the NCC acquired the block as part of its “Mile of History” initiative to create a dignified ceremonial route between Parliament Hill and Rideau Hall. The NCC acquired and restored many buildings along Sussex Drive as part of this project, and restored them to their Confederation-era appearance. A devastating fire in 1980 then destroyed much of the newly restored building. It was reconstructed in 1981, retaining the original 1870s façade and restoring its distinctive mansard roof.