High Quality Content by WIKIPEDIA articles! Council House 2 (also known as CH2), is an office building located at 240 Little Collins Street in the CBD, in Melbourne, Australia. It is occupied by the City of Melbourne council, and in April, 2005, became the first purpose-built office building in Australia to achieve a maximum Six Green Star rating, certified by the Green Building Council of Australia. CH2 officially opened in August, 2006.