Ensure your builder meets or exceeds local requirements of the Model Energy Code (MEC) recently re-issued as the “International Energy Conservation Code” which considers basic building “shell” and mechanical systems.
Insist upon air-sealed construction and have a “blower door” test done to confirm quality. You want your home to be air-tight.
Require the installation of an appropriate controlled mechanical ventilation system (cold, or very-hot climates this should be a heat-recovery ventilator type).
Choose energy-efficient windows (see Windows Tips) that are rated by the “NFRC” or have an equivalent energy performance warranty from the manufacturer or builder.
Plan for effective natural lighting in the home’s layout of floor spaces and windows and skylights. Daylight with “tubular” skylights where spaces would have no windows.
Install insulated doors, and use double-pane glass indoors with vision panes. Mild areas go with R-2.5, while colder areas go with R-5 doors
Design for “passive solar” where the homes architectural features help seasonally heat and cool the interior.
Specify your builder shall use locally produced building products and other “green” building materials with greater recycled content.
Select mechanical systems and appliances that have DOE “energy guide” labels in the most efficient 20% range of their product performance category. Energy Guide labels are provided under Federal law for most major appliances and home systems.
Use drought resistant landscaping and planting that shade the home without significantly reducing the amount of winter-time sun for south-facing windows.