A new study casts doubt on whether the target energy-efficiency reductions often cited in legislation and other calls for mandatory reductions are economically feasible. The study, released by Herndon, Va.-based NAIOP, a commercial real estate development association, found that although significant energy efficiencies can be achieved, reaching a 30% reduction above the American Society of Heating, Refrigerating and Air Conditioning Engineers’ 90.1-2004 standard is "not feasible" and would exceed a 10-year payback. The standard is usually the benchmark cited by lawmakers and other officials. The study, conducted by ConSol, a California-based energy-modeling firm, used a building energy-simulation program to compare energy efficiencies achieved on a prototype commercial office building across three time zones. The maximum efficiency reached was 23% in the Chicago model, with 21.5% in savings in Baltimore and 15.8% in savings in Newport Beach, Calif.