Insulation
Cracks in insulation allow cold air to flood into a house. Such breaches worsen the energy performance gap – the difference between the predicted performance of a building at design stage and actual performance once built. This gap is “around 60% in non-Passivhaus homes”, says Sarah Lewis, research and policy director at the Passivhaus Trust.
By tightening energy efficiency regulations, we can close the chasm. The gold standard is Passivhaus accreditation. ‘Passive houses’ form a “single thermal envelope”, Lewis explains,