Executive Summary This report investigates a range of energy efficiency information systems in Europe and the United States. The analysis shows that a number of tools and systems have effectively provided information that allows the property and financial markets to value energy efficient buildings and drives large scale household retrofit activities. The report identifies key characteristics of an effective information system, covering the type of information provided to households, when this information should be provided, who should provide the information, what form it should take, and what systems are needed to facilitate the process. Based on this analysis, the report highlights a series of opportunities to enhance the effectiveness of future Australian energy efficiency information systems: 1. Develop a “reduced data” energy efficiency rating for application to existing buildings to provide simple energy efficiency information. 2. Include information that people care about in rating tools and information systems, as identified through ongoing EnergyFit Homes research 3. Maintain a discrete star label for ratings while ensuring that the scale is appropriate for existing buildings 4. Develop renovation advice as a key component of the energy efficiency rating application for existing buildings 5. Incorporate the existing building rating in a point of sale and lease energy efficiency information disclosure program, in partnership with the Liveability Property Features framework 6. Ensure adequate quality assurance that balances rating reliability and consumer protection with cost and ease of access for any future systems 7. Build an integrated program to stimulate large scale retrofit activity in the Australian existing household market, using an effective rating and information system as described above, delivered by engaged industry partners in the property and energy efficiency sectors, and supported by cost effective public/private investment.