Air tightness may be a new word to many of us but over the next number of years it will be vital when building all new homes. It is however simply the control of airflow within a building ensuring there is no air leakage, which can occur through gaps and cracks.
Air tightness measures the amount of air flow entering and leaving a building. Any Air leakage within the building will increase the amount of heat loss as warm air is displaced by colder air from outside. The colder air then needs to be heated. The more airtight your house the less air changes and therefore the less you will spend heating it.