As the UK moves forward to meet the 2016 Zero Carbon target, we have limited feedback from the impact of the 2010 Parts L and F revisions – but it now appears the compliance calculations are leading increasing numbers of house-builders towards greater airtightness in fabric and mechanical systems for ventilation. At the same time, there is increasing scientific awareness of the behaviour of potentially polluting materials and substances in the indoor environment.

This interim report makes recommendations for changes needed to ensure that whilst delivering energy benefits, our homes deliver a healthy internal environment.