December 12th, 2017
This review assesses the current state of knowledge on indoor air quality in energy efficient, airtight houses in the UK and elsewhere in the world. It summarises the characteristics of homes built to Levels 4, 5 and 6 homes of the Code for Sustainable Homes, and discusses the relationship between indoor air quality and occupant wellbeing. Research in the UK, Europe and the rest of the world into indoor air quality and other factors which may impact on occupant wellbeing is reviewed. This is followed by a review of current research and state of the art for ventilation performance in dwellings and of construction and ventilation provision in highly energy efficient homes. Experience of building airtight homes in countries in very cold climates, such as Canada, central Europe, parts of the USA and Scandinavia, provides insights into construction practices that may be increasingly adopted in the UK. However, direct transfer of knowledge is problematic and there is a dearth of information about indoor air quality in highly energy efficient structures. Requirements for research into the performance of highly energy efficient homes and the quality of the internal environment ventilation systems, and the impact on the health and wellbeing of occupants, are identified. The review is based on an extensive literature review of over 100 references and publications, and includes appendices relating to the Code for Sustainable Homes, PassivHaus, Canadian R-2000TM homes, and the US EPA Indoor airPLUS specification.