The house should be designed with a continuous air barrier. All the cracks, holes, and exterior envelope penetrations of the home’s six-sided box must be systematically sealed.
All penetrations will be minimized - for example:
- ERV/HRV vents replace bathroom and kitchen venting systems.
- All lighting, plumbing, and electrical will be run inside the air barrier. Lowered ceilings and smart design will be used to eliminate as many penetrations as possible.
- Outside electrical outlets will be placed on the porch and garage - not on the highly-insulted structure.
- Exterior faucets will be eliminated - or minimized to one outside the kitchen.
- Plumbing stack vents will be combined when possible.
- Combustion is eliminated in the mechanical systems and appliance choices.
- Windows and doors will be properly sealed
Using a Thermal ByPass checklist during the design phase will help ensure that all aspects of designing a continuous airtight thermal barrier are considered. An in-depth Thermal ByPass Checklist is available from Energy Star and another is available from Green Building Advisor.
The thermal barrier should be explicitly detailed on the home design. Blower door tests will be used to certify that the shell is properly sealed before any of the insulation and finishing work starts.