Door blower test
Door blower tests become mandatory for new house as of July 2008, and for all other homes in January 2009.
Improving air tightness in a dwelling can reduce air leakage. Optimum building design should strike the right balance between air tightness and ventilation. "Passive" houses in particular often use mechanical heat recovery ventilation which require an extremely air tight house.
Also, for any customer thinking of having a thermogrphic survey done on their property, an air tightness test is also a very useful complementey test which helps find leaky spots in the property.