The Goldilocks Approach to Tight Houses: Is There A ‘Just-Right’ For Leakiness?
Sealing leaks in the building envelope, along with a blower-door test to confirm the results, have become accepted parts of energy efficient building. Air leaks add up to significant energy losses, and they can carry substantial amounts of moisture into roof and wall assemblies, risking mold and decay.
The flip side of tighter houses is the need for mechanical ventilation, and that inevitably leads to higher construction costs.
In this week’s Q&A Spotlight from Green Building Advisor, an energy retrofitter with a limited budget wonders whether all houses must bear the added expense of a ventilation system. Is it possible, she wonders, to build to somewhat less stringent air-sealing requirements and bank on leaks through the building envelope to meet fresh air requirements?