Are our homes making us ill? The impact of energy efficiency on indoor air quality

Recent research testing and post-occupancy evaluation3 of new-build homes across Scotland constructed to the 2010 standard of 5 m3/m2/h at 50 Pa measured carbon dioxide levels in occupied bedrooms to be two to four times above the 1,000 ppm threshold that is commonly taken to represent reasonable indoor air quality. Improving indoor air quality by installing mechanical whole house ventilation systems incorporating heat recovery increased lung function by over 20 L per minute in a cohort that had general practitioner diagnosed 'severe' asthma - compelling evidence that comprehensive allergen avoidance measures can produce immediate and significant improvements in a sensitised cohort.