The impact of energy efficient refurbishment on the airtightness in english dwellings

Fan-pressurisation method was used to test the air infiltration rate of 191 dwellings in England. All tested homes were either pre or post the introduction of energy efficient retrofit measures such as cavity wall insulation, loft insulation, draught stripping and energy efficient heating system. Results show that the average air infiltration rate of the post dwellings is only marginally lower by 4% compared to the pre dwellings. Component infiltration rate based on model prediction indicates the combination of cavity wall insulation, loft insulation and draught stripping potentially reducing infiltration rate by 24%. On the other hand, longitudinal comparison shows a retrofit gas central heating system offsets this effect by contributing 13% increase in infiltration rate.