Windows: Windows are the most common place for homes to lose warm air in the winter and cool air in the summer. Glass is an excellent conductor by which hot and cold air move quickly in and out of homes, meaning your heating and cooling systems have to work much harder to keep you comfortable. To help keep that air where you want it, consider using energy-efficient blinds and replacing your windows with energy-efficient ones. Also, look for "low-E" windows, which often have double panes with argon or krypton gas between the panes. This gas barrier helps reduce conductivity without affecting the view.
Aluminum Frames: Aluminum frames do not rank especially high as an energy-efficient option because they are heat conductors — the flow of energy is not as regulated as with other framing products. They are quite cost effective, and it doesn't take much to maintain them.
Vinyl Frames (Also Called PVC, uPVC, and PVCu): Vinyl frames are more energy efficient than aluminum frames. They're popular for their low cost, low maintenance, and resistance to moisture.
Wood Frames: Wood frames are energy efficient, though they will cost you quite a few pennies at the outset and in regular maintenance costs. They are relatively easy to repair if broken, and you can ensure a sustainable product by purchasing from a certified supplier.
HVAC: For HVAC systems, ductwork should be sealed with mastic, a concrete-based paste that is painted over the joints to prevent air leakage, or with foam insulation. Air-conditioning systems with a SEER (Seasonal Energy Efficiency Ratio) of 15 exceed the code minimum of 12. With houses being so tight, it is recommended that you include an outside (fresh) air intake.
Plumbing: Dual-flush toilets that use 0.8 gallons of water to flush liquid or light waste or 1.6 gallons of water to flush solid waste are recommended. Kohler claims that these types of toilets can save up to 2,000 gallons of water per year.
While residents leave the heat off in their homes when they leave for vacation, the same cannot be said for hot water. It seems only logical to leave the hot water off when it is not needed. This is the logic behind the "tankless" or "instant" water heater, which provides on-demand and instantaneous hot water at an efficient and less costly rate. Although the intangible savings of fossil fuel pollution and water waste are not immediately apparent, the fact that energy and water are such indelible aspects of a home's eco footprint means that the water heater is an ideal target for those aiming to conserve.
Tankless heaters not only save several square footage of storage space, but also prevent standby energy losses and sitting water. Typical tankless water heaters can be about 35% more energy efficient than traditional storage tank water heaters for a home that uses about 40 gallons of hot water a day.