GOING GREEN: HOMES WITH SOLAR PANELS SELL FOR 4.1% MORE

More than 80 percent of home buyers say energy-efficient features are important, a truth that's reflected by data showing homes with solar energy systems fetch higher prices. A new Zillow analysis shows homes with solar-energy systems sold for 4.1 percent more on average than others nationwide in the past year[ii]. The sale premium varies by market – 5.4 percent in New York, 4.4 percent in San Francisco and 3.6 percent in Los Angeles, for example. This Earth Day, Zillow is highlighting a green initiative that helps inform homeowners and buyers about their own solar potential by putting a Sun Number on more than 84 million homes nationwide. The Sun Number provides a sense of each home's solar-energy potential and the energy savings that comes with it. Creating the Sun Number is more complicated than simply looking at how many sunny days a city sees each year. Sun Number, the company that produces its namesake metric that's displayed on Zillow, measures the roof of each home and calculates the pitch, orientation and size of each roof plane. It determines the amount of sun that hits every square meter of the home's roof -- taking into account factors like trees or taller buildings that might block sunlight. Finally, it adds in local factors like the cost of electricity and solar, and the local weather conditions, to compute a Sun Number somewhere between 0 and 100. The higher the score, the more suitable for solar that house is.