A recent study of low-energy, high-performance commercial buildings in the U.S. found that while the buildings do save energy -- 25 to 70 percent lower energy consumption than allowed by code -- more can be done to achieve the Department of Energy (DOE) goal of having marketable net-zero energy buildings (ZEB) by 2025. Commissioned by DOE's Building Technologies Program and conducted by the National Renewable Energy Laboratory (NREL), the study analyzed six buildings that represent the current generation of low-energy commercial structures. Not surprising, the study concluded that today's energy-saving technologies can substantially change how buildings perform when they are applied together and properly integrated in the design, installation and operation of the building. The full study report can be viewed at the NREL website.