The Stern Report found that Climate Change is the world's greatest market failure, and the United Nations concluded it is likely to be the most significant environmental challenge of our time. This paper aims to illustrate building Greenhouse Gas (GHG) and energy trends, and to provide practical strategies and best practice examples in international low- and high-rise building refurbishments to lower GHG emissions, energy use and operating costs, across building types and Australian Climate Zones. These can be adopted by policy-makers, owners, investors and occupiers. It also aims to provide examples of government policies and important stakeholder behaviour to reduce GHGs, and evaluates one recent project for strategies that proved successful and those that could be improved. The method used was to review international strategies that lower building GHG emissions in countries with more advanced building regulations than Australia, and to discover affordable and effective strategies from associations that publicise case studies. This paper shows that the operational phase of buildings is a significant contributor to global GHG emissions; that Passive building refurbishments are current best practice strategies; and that occupant behaviour is another surprisingly significant contributor to GHG emissions. The paper forms part of the author's higher research degree literature review.