In most office buildings, a lot of energy -- and money -- goes right out the window. Improve your insulation by sealing any leaks around doors and windows, as well as in air ducts. And don't over-cool or over-heat your office. In winter, keep temperatures between 65 and 68 degrees Farenheit during the day and between 60 to 65 degrees at night. In the summer, set the thermostat between 70 and 80 degrees during the day and at 80 degrees at night. Reduce Travel Decrease your carbon footprint by limiting business travel. When possible, teleconference with clients and employees in remote locations instead of meeting in person. If your business travel is nonnegotiable, you may wish to purchase carbon offsets for the miles you and your employees fly or drive. If you have a company vehicle, or a fleet of vehicles, consider switching to hybrids . You're guaranteed to save a chunk of change in gas, and you may also be eligible for individual or business federal tax credits as well as local incentives . Another option is to follow in the footsteps of businesses like UPS ( UPS) and Maine's Oakhurst Dairy , which have converted at least part of their fleets to biodiesel. Reduce, Recycle, Refurbish Save a few trees by encouraging emailing instead of paper memos, printing on both sides of the page, recycling used paper and buying paper made from recycled content. Consider leasing office equipment or buying equipment from companies that offer to take back the product at the end of its life. For instance, Xerox ( XRX) offers TradeUps , which allow customers to return used equipment for a rebate toward a new model. Xerox will reuse as much of the old product as possible and recycle the rest.