Any building or office that hasn't had a comprehensive energy upgrade in the last five years is throwing away money – guaranteed. 

At one time, a building upgrade was truly exceptional if it achieved a 25 to 35 percent reduction in energy consumption with a three- to five-year simple payback. That’s a 20 percent to 35 percent return on investment. Today it's possible to achieve a 35 percent to 50 percent energy savings, often with a faster payback. And companies can finance many of these upgrades off the balance sheet.  

A recent study of nearly a thousand energy-efficient upgrades involving one or more major building systems - lighting, electric motors, drives, heating and cooling, control systems - found average energy savings of 39 percent, and an average return on investment of 32 percent. Businesses can expect to achieve a savings of $1 per square foot of floor space with the kinds of whole-building upgrades described in Cool Companies. With four to five million commercial buildings in the U.S., these potential savings are vast:  

• The 48-story, 1.6-million-square-foot office tower at Four Times Square at the corner of Broadway and 42nd Street in New York City cut energy and greenhouse gas emissions by 40 percent compared to New York Building Code requirements. The building combines comprehensive energy efficiency with a variety of Cool Power tools, including non-polluting fuel cells, cogeneration and rooftop solar panels. The building also has an extremely efficient natural gas-fired air conditioner. Annual energy savings of $500,000 will pay for the efficiency measures within five years. The Durst Organization, which owns Four Times Square, says lessons learned in this project will help deliver even better results on their next skyscraper. 

• The State Capitol Extension in Austin, Texas was state-of-the-art in 1992. Designed with energy efficiency specifically in mind, it averaged about one third less energy use per square foot than other Capitol Complex buildings. Even then, visiting energy experts still uncovered further savings potential. Simply by optimizing heating and cooling they cut energy use an additional 27 percent, reduced worker complaints and saved about $140,000 a year. The payback: less than three months.  

• Henningsen Cold Storage Company's award-winning 50,000-square-foot refrigeration facility in Gresham, Oregon uses 58 percent less energy than a comparable conventional facility, saving more than one million kilowatt hours a year. The heavily insulated plant uses high-efficiency evaporators and condensers and a state-of-the art control system that improves quality control. Fast-acting doors on loading docks minimize energy losses. Bilevel lighting in individual rooms provides automatic dimming. The improvements also extend equipment life and improve service quality. "This project reduces our power bill and improves our bottom line," according to the company's engineering services manager. "And since we know more about what's going on in our facility, we make better decisions."  

• The Amtrak passenger station in Bloomington, Illinois that combines a 2.4- kilowatt rooftop solar array with extensive efficiency measures uses 75 percent less energy than a comparable station. Efficient lighting reduces lighting energy more than 70 percent. Passive solar heating, thorough insulation and outdoor shading cut climate control needs. Savings of $20,000 a year paid for the extra costs in about five years.  

• The Ridgehaven City Office Building in San Diego cut energy consumption more than two thirds, saving $80,000 a year. The building is now 60 percent more efficient than an identical city office next door. Utility financing reduced a 3-year payback to an instant one.  

• BlueCross BlueShield of Oregon cut energy use 61 percent at its Portland, Oregon headquarters - savings worth $130,000 a year. BlueCross put up no money for the project, instead paying for it entirely from the monthly energy savings.  

• The M.D. Anderson Cancer Center in Houston cut energy used for heat and cooling by 30 percent each for a total savings of $150,000 a year, about a quarter of the building's annual energy cost.  

• Utah's 120,000-square-foot Department of Natural Resources building in Salt Lake City beat the energy requirements of the standard building code by 42 percent with a six-year payback. The various efficiency measures, including extensive daylighting, reduced cooling loads by about 90 percent compared with a conventional building.  

• The National Renewable Energy Laboratory's 10,000-square-foot Thermal Test Facility in Golden, Colorado uses 63 percent less energy than conventional construction.  

• The 16,000-square-foot California State Automobile Association building in Antioch, California adopted a comprehensive energy-efficiency package that cut energy use 64 percent compared to other new office buildings.  

• Pittsburgh's 10-story, 175,000 square-foot Comstock Building has half the normal energy costs of other large office buildings in the city, but cost $500,000 less to build.