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Inadequate insulation and air leakage are the main causes of heat loss in homes.

One of the most recent approaches to reducing heat loss from homes is to make the home airtight so that air and moisture cannot move freely through the building structure. If air can move uncontrolled through the structure of a building then this can reduce the effectiveness of insulation and let in moisture, which can eventually cause the insulation to deteriorate.

The concept of making your home airtight is comparable to wearing a thin windproof jacket over a woollen jersey in a cold wind - an airtight membrane is wrapped around the entire building structure to protect against air movement and retain heat.

The downside of airtightness systems is unless it is paired with a mechanical ventilation system, a home will become stuffy and unhealthy as moisture and condensation can become trapped. Mechanical ventilation (or ‘heat exchange’) systems enable your home to “breathe”, but are presently quite expensive - in the vicinity of $15,000, so the actual exercise of making a home airtight can require significant investment. Research conclusively proves that excessive moisture levels in a home will make it harder to heat and will also reduce the value of double glazing and insulation.