Under ACES, many will. The bills Retrofit for Energy and Environmental Performance program establishes a national building code mandating energy improvements in existing buildings compared to the baseline 2005 level: At the start of 2018, buildings would need to use 5 percent less energy than the baseline, with additional 5 percent efficiency improvements every three years culminating in a 25 percent improvement by January 2030. REEP also creates mechanisms for public funding, loan guarantees, interest subsidies and other credit support to help owners make energy improvements. Requiring owners to enhance efficiency while providing the means to do so represents a balanced solution that will put a big dent in greenhouse gas emissions.If the 70 percent of electricity use that comes from buildings could be cut by a third in 10 years and by half in 20 years, what would be the effect on the cap-and-trade system? With less demand for electricity from the commercial sector, power companies may discover they can stay within their capped emission levels without relying heavily on renewable sources.In addition, the push for energy reduction has positive effects on the economy. Not only does it create jobs in many industries, but it ultimately makes businesses operate more cost-efficiently, a key driver of profitability.Ultimately, though, the best reason to pursue energy conservation is the most universal: Economic growth based on nonrenewable energy sources is a model that cannot be sustained indefinitely. As we have seen with the recent economic meltdown, turning a blind eye to growing problems only makes dealing with them later much more painful. The need for energy action is apparent. An effective, sensible action plan is on the table. We should seize this opportunity.Lauralee Martin is chief operating and financial officer of Jones Lang LaSalle, a global financial and professional services firm specializing in real estate. Mindy Lubber is president of Ceres, a coalition of investors and environmental groups that coordinates Business for Innovative Climate and Energy Policy.