The Commonwealth Department of Environment and Heritage’s Australian Greenhouse Office commissioned this study undertaken with Sustainable Built Environments. The study compared building code requirements from 8 different Australian cities from different climate zones with similar overseas locations in the USA, UK and Canada. A total of of 51 house plans were also rated using current Australian AccuRate software. The study showed that, on average, current overseas house designs would perform to almost 7 stars if they were to be built in equivalent climate zones across Australia. In Australia, buildings are currently required to meet a minimum of a 5 star energy efficiency rating. This research demonstrates that Australia still has room for improvement with its new house building code requirements and design performance for energy efficiency.