The Scottish Government outlined their move towards zero carbon development in the Climate Change (Scotland) Act 2009. Section 6 of the 2010 Scottish Building Standards requires a reduction of 30% in CO2 emissions from domestic buildings from the 2007 Standards. To help achieve this, mandatory air tightness testing was introduced for new builds in 2011.
Air leakage is the uncontrolled flow of air through a building. Excessive air leakage leads to poor energy performance, draughts and high energy bills. So, air tightness is an extremely important element in sustainable building design. Air Tightness Testing enables the correct air permeability to be achieved without creating health problems, condensation or decreasing the integrity of the building fabric due to lack of natural ventilation.
The minimum number of houses to be tested for air tightness in large new developments is one in twenty, including at least one of every dwelling type. It is good practice to increase this ratio to ensure a consistent quality of construction. Smaller developments usually require a greater proportion of dwellings to be tested to ensure a representative sample is taken. In single dwelling developments an air tightness test is usually undertaken in each case.