The design and insulation of households is also very important to overall energy consumption.  While these changes are more costly and harder to implement, they are important to having an energy efficient home.  Active HVAC (Heating, Ventilation, and Air Conditioning) and insulation are two ways to reduce unnecessary electricity usage in the home.

There are three primary components of HVAC conservation that residents can incorporate into their development plans:

1. A building envelope that maximizes energy performance
2. Utilization of an effective ventilation system that provides efficient transportation of fresh air
3. Elimination of unnecessary use of HVAC systems

• Insulate attic, outside walls, floors over crawl space, etc.
• Add insulation to attic access panels or pull down stairs.
• Install insulation in gaps around pipes, ducts, fans or other items that enter the attic or exit the house from a conditioned space.
• Install 1 square foot of attic ventilation per 300 square feet of attic space.
• Use outlet and switchplate gaskets to reduce air infiltration.
• Caulk, seal and weather strip around windows/doors.

Multipaned Windows: Double- or triple-paned glass windows placed on the exterior of the building reduce the rate of heat loss from the building.
Tinted, Reflective, or Shading Glass: Tinted or reflective glass or shading films installed on the exterior of the house will reduce the rate of solar penetration into the house.

2) Maximizing air change effectiveness also reduces the energy consumed from HVAC systems:

Displacement ventilation is a strategy that distributes air into a space using low velocity airflows, resulting in higher indoor air quality and reduced energy consumption by utilizing the natural convection flows already existing within the building.

The Economizer Cycle is an HVAC conservation feature that allows access, up to 100%, of outside air for use in cooling when outdoor air temperatures are lower and drier than supplied air. This system reduces the air-conditioning load of the HVAC system and minimizes overcooling and unnecessary heating, resulting in energy conservation. It also allows fresh outside air to be incorporated into the ventilation system when ambient conditions are appropriate, potentially resulting in a higher air quality within the home.

3) By incorporating individual controls to the HVAC system into many small spaces within a home, the HVAC load can be adjusted throughout the building according to individual needs. This allows for reduced energy use when conditioned air is not needed, such as when certain spaces are unoccupied.

A Variable Air-Volume (VAV) system operates on the principle that space temperature can be maintained by varying the volume of constant temperature air delivered to the area as the load changes. This system supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. These systems are able to save large amounts of heating, cooling, and fan energy compared to other HVAC systems (i.e. Constant Volume Systems). They also provide greater flexibility to the building designer because they can accommodate different air-conditioning load profiles within a large space.

Source: http://www.fhp-mfg.com/commercial/vav/vav.htm

Advantages of VAV systems outlined by FHP Manufacturing Company:

• It has the ability to control temperatures in interior and exterior zones without under or overcooling
• It includes the capability of taking advantage of varying loads as a result of the sun's diversity
• Low installed first cost
• It is readily adaptable to night set back and compatibility with energy management systems
• The system is economical to operate since the amount of air being moved is only that required to satisfy the load
• It is suitable for partial operation of a building such as overtime or weekend usage of a particular area