Airtightness is the control of air leakage, the elimination of unwanted draughts, through the external fabric of the building envelope. It is one of the defining design requirements of a high-performance building.
This may be achieved properly creating an airtight system. A continuous air barrier separating the interior conditioned space and the exterior environment provides comfort, optimizes the insulation and helps keep the assembly free from condensation and mold.
Why build for airtightness?
A BETTER ENVIRONMENT:
Airtight buildings help reduce the carbon footprint of our built environment, by achieving low energy consumption that can also greatly reduce the cost of maintenance, heating, and cooling.
A HEALTHY HOME:
It is estimated that we spend up to 90% of our life in buildings. Therefore, the quality of indoor air is extremely important for our health. Mould and fungus may occur in conventional buildings because of excessive moisture penetration to the fabric of the building. The airtightness system eliminates these issues, resulting in a higher level of air quality in the house creating a healthier home and more durable building.
How do we achieve airtightness?
While conventional buildings have a multitude of compromising penetrations, the air barrier in a high performing building should continue uninterrupted. But to get the necessities of a contemporary home such as light, water, ventilation, electricity, some punctures in the building envelope are unavoidable.
For a high-performance building, all the penetrations in the building envelope need to be intentional, integrated, and properly sealed with specified technical solutions: the windows and doors openings are sealed with intelligent airtight membranes that ensure no air leakage occurs around the frames; the penetrations for installation equipment (like ventilation, electricity, water) are sealed with a spray able airtight membrane that blocks any air movement around the pipes. These measures ensure that the insulation functions to its optimum performance, saving energy and drastically reducing carbon emissions and costs of maintenance for the lifetime of the building.
Air leakage vs controlled ventilation
All buildings must be ventilated for health and comfort and that’s exactly the same for an airtight building. While ventilation is intended and necessary, air leakages are not.
When building an airtight house, a suitable ventilation system is planned in the design process. The ventilation system keeps the building constantly ventilated with fresh outside air, while recovering the heat being emitted from the inside environment.
