Background The 2002 Energy Performance of Buildings Directive (EPBD) is designed to help the EU meet its commitments under the Kyoto agreement, and respond to issues raised in the Green Paper on the security of energy supply. It has a key role to play in promoting the identification and implementation of effective energy savings measures in the building sector, where residential buildings currently account for approximately 40% of energy use. Objectives The project will focus on the assessment of national programmes to improve the energy performance of existing housing stock, such as government supported improvements in thermal insulation, which is seen as a cost-effective and proven measure. Specific objectives include: To develop a common protocol for assessing the impacts of a building’s energy performance on indoor environmental quality and health and to establish an integrated approach for the assessment of environmental and health information, including demonstrating the use of relevant environmental and health indicators; To demonstrate the effects (both positive and negative) of energy efficiency on Indoor Environment Quality (IEQ) and health in two-to-three different European countries; To develop guidelines to support the implementation of related policies; and To facilitate transnational networking and the dissemination of information. Expected results At national level, the expected results include: An annual reduction in energy consumption (Twh/m3/yr) through changes in the U-values of buildings and changes in energy performance related to certification in residential buildings; Improvements in thermal conditions, through the optimisation of indoor temperatures and relative humidity; Improvement in building structures, reducing the risk of damp/mould growth; Improvements in indoor air quality though better ventilation (air exchange rate); and Improvements in occupants’ behaviour, health and wellbeing, including improved cardio-respiratory health, a reduction in allergic diseases and increased thermal comfort.