Thermal anomalies such as thermal bridges should be minimized. Moisture gain resulting in decreased thermal and structural performance should be controlled. Air flow retarder systems and vapor diffusion retarders should be used to protect the building envelope from uncontrolled air and moisture flow. Fenestration systems should be selected according to climate, building orientation, interior comfort, daylighting, ventilation, furnishing durability and egress requirements. B. Mechanical Systems Indoor air quality should be facilitated by the installation of a controlled mechanical ventilation system.
Heat recovery is recommended in severe heating climate zones.
Only sealed combustion or power vented direct combustion appliances should be installed in occupied spaces. Gas cook tops and gas ovens should only be installed in conjunction with exhaust fans. Thermal and peak load reductions derived from improving levels of insulation, airtightness and fenestration performance of the building envelope should be evaluated in the sizing of equipment. The domestic hot water system should meet high efficiency standards. Options for reducing water consumption are recommended.