The National Association of Home Builders Research Center reports that significant changes in the Home Energy Rating System (HERS), used to measure a
The National Association of Home Builders Research Center reports that significant changes in the Home Energy Rating System (HERS), used to measure a home’s energy efficiency, will be phased in by January 2007. The new HERS rating system incorporates on-site energy, lighting, and appliances to bring ratings in line with the most recent energy code. In a complete reversal of the old rating method Û where 100, on a scale of one to 100 indicated the best possible score Û the new HERS index based on the 2004 International Energy Conservation Code awards a home built to code a score of 100. For every 1 percent reduction in annual energy consumption, the HERS index is lowered by one point. Under this system, a zero-energy home scores a 0 rating, and a house using twice as much energy as the code home receives a HERS index of 200.
Under the old system, a score of 86 or higher was needed to obtain the Energy Star label. Under the new HERS index, a home in a cold climate needs a HERS index no higher than 80 (20 percent more efficient than the reference home) to meet Energy Star requirements. In moderate or hot climates, an index no higher than 85 is required. Star ratings may be helpful for builders promoting the energy-efficiency of their homes, the Research Center notes. The best homes, those scoring 50 or less, receive a five-star-plus rating.