utility companies, the ECH program offered incentives and training to concerned builders who would incorporate energy efficient features into their projects.Some of the criteria necessary to meet the program's requirements included:

1) Air tight construction. The building shell had to be sealed in such a way as not to allow more than 1 square inch of leakage per 100 square feet of shell area at a pressure of 4 Pascal's. This was tested using a blower door test--a test where the house is depressurized and leakage measured through pressure differences.

2) Installation of a fresh air ventilation system. Because of the tightness of the house, fresh air is introduced to the living areas to improve IAQ.

3) Sealed combustion. Again, because of the tightness of the house, all fossil fuel burning appliances had to have their own make up air systems to prevent back drafting.

4) Energy efficient lighting.  There was a requirement to install a minimum of 10 compact fluorescent or other energy efficient lighting per 1000 square feet of living area.

Although building 'tight houses' had been Carl's modes operandi, the introduction of fresh air ventilation solved a lot of the problems he had encountered on earlier structures--the design build philosophy being to build tight and control the introduction of fresh air to the spaces that need it.