It is a response to an increasing need to address carbon emissions from existing residential buildings. Historically, policy on reducing carbon emissions has focused on regulating new-build projects; however, with less than 2% of the building stock in Australia replaced each year, there is a clear need to reduce carbon emissions in homes that have already been built and occupied. The document builds on key research conducted nationally by individuals and organisations, including the Australian Government’s Department of Environment and Energy and local universities, working in the areas of low carbon retrofit options, housing typology and climate. The practical nature of the information aims to appeal to a diverse readership, from people with little or no formal training or experience in construction and design to those who are qualified builders and architects. Importantly, the advice here covers only residential buildings, which include the National Construction Code building classes 1, 2 and 3. For commercial retrofits,please refer to the Guide to Low Carbon Commercial Buildings – Retrofit. Similarly, homeowners embarking on extensive refurbishments that significantly change the form or layout of their dwelling, or who are planning home extensions or a new construction, should refer to the Guide to Low Carbon Residential Buildings – New Build. Homeowners or those in rental properties who are seeking to avoid major retrofits while at the same time reduce their household energy use should refer to this guide’s companion document, the Guide to Low Carbon Residential Buildings – Households.