140 William Street (formerly BHP House) is a 41-storey steel, concrete and glass building located in the eastern side of the central business district of Melbourne, Victoria, Australia. Constructed between 1969 and 1972, BHP House was designed by the architectural practice Yuncken Freeman alongside engineers Irwinconsult, with heavy influence of contemporary skyscrapers in Chicago, Illinois. The local architects sought technical advice from Bangladeshi-American structural engineer Fazlur Rahman Khan, of renowned American architectural firm Skidmore, Owings & Merrill, spending ten weeks at its Chicago office in 1968. At the time, BHP House was known to be the tallest steel-framed building and the first office building in Australia to use a “total energy concept” – the generation of its own