Geothermal Heating and Cooling - This system uses heat from the earth to heat and cool a home, and can also provide hot water. Just below the earth's surface, the temperature remains a constant 50 degrees. This system takes heat from or adds heat to fluid that circulates through tubes installed in the ground. Although there can be substantial upfront costs, the savings on energy bills is significant. What's more, this system does not directly add to carbon dioxide emissions.

Daylighting - This design technique allows more natural light into a home during the day, thus reducing the need for artificial light. This is better for energy consumption and the overall mental state of occupants thanks to the essential vitamins that sun exposure provides. Daylighting is possible by strategically placing windows in areas that need additional light and adding skylights or sun tunnels. In addition to providing light, when strategically placed, the windows can add passive solar heat, which can further decrease energy costs.

Solar Hot Water Heating - This strategy uses solar collectors that circulate water or other heat-transferring fluids through tubes. This energy goes to a water tank that heats the water. While significantly more expensive than traditional hot water heaters, the entry price is not cost prohibitive.

Water Conservation - There are a variety of methods to reduce the amount of water a home uses without decreasing occupants' usage habits.

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  PEX Central Manifold Supply - These systems run individual hot and cold supply lines to each fixture from a central manifold.

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  Recirculating Hot Water - Hot water circulates continuously through the house. When water is needed, it is instantly on. This feature can save about 15,000 gallons of water for a family over the course of a year because people do not need to wait for the lines to clear before hot water is delivered. There is an energy cost associated with continuously heating the water, but it is less than the cost of the wasted water.

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  Low Water Use Fixtures and Appliances - There are a number of fixtures that can be installed without compromising performance - low-flow showerheads and toilets, front-loading washers and water-saving dishwashers.

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  Gray-Water Systems - This system uses two different collection mechanisms. The first captures water runoff from the roof. The second uses lightly used water from showers, sinks and washing machines. The reclaimed water can be used for irrigating or flushing toilets.

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  Xeriscaping and Low-Water Use Irrigation - Landscaping with natural plants that do not need irrigation is an easy way to decrease water usage.

Foam Insulation - Using foam insulation in existing wall cavities and other leak-prone areas is an easy fix for removing air leaks. The foam bonds to wood and can flow around wires and electrical boxes to create tight seals. What's more, foam insulation has a higher R-value than other blown-in insulation. Foam insulation also lasts longer and doesn't settle in the cavities. Homeowners will also notice that the house is quieter.

Energy Recovery Ventilator (ERV) or Heat Recovery Ventilator (HRV) - Especially in tight houses, indoor air can hold up to 10 times the amount of pollutants as air outside. As a result, it is crucial to continuously swap stale interior air for fresh exterior air through a ventilation system. The best types are balanced ventilation systems - ERV-s exchange both heat and moisture from stale air to fresh air, while HRV's exchange only heat. An HRV is less expensive but also requires a separate humidifier; these are recommended for northern climates. ERV's also remove water from the exterior air during the cooling season. Because a major portion of energy for cooling a building comes from moisture removal, an ERV is more efficient for air exchange in the cooling season.