What can be done to make office buildings more energy-efficient?

What can be done to make office buildings more energy-efficient? So many leave thousands of lights on at night!

—- Deborah, Baltimore, MD

Office buildings are indeed the top energy guzzlers among commercial buildings in the United States, head and shoulders above retail and service establishments and even manufacturing facilities.

The U.S. Department of Energy says that office-building owners spend an average of $1.34 per square foot annually on electricity. Lights, office equipment and heating/cooling systems account for about 90 percent of this expenditure. Lighting is clearly the main culprit, comprising 44 percent of all usage. Office equipment—computers, printers, copiers, fax machines and telephone systems—accounts for about 23 percent.

Building managers can make a big difference by installing energy-efficient systems—from heating and cooling to lighting and waste disposal—but individual business owners and their employees can also have impact by simply turning off lights and shutting down dormant machinery during non-working hours.

According to Advanced Energy, a North Carolina-based non-profit organization that monitors and analyzes energy use in commercial spaces, replacing older traditional fluorescent tubes with newer and more efficient compact fluorescent bulbs can save as much as 30 percent on electricity. And installing occupancy sensors so that lights go on and off as people enter and leave rooms can save an additional five percent. Furthermore, building managers can save up to 15 percent on electricity bills by programming thermostats to trigger warming and cooling as needed during the workday while hibernating at night and on the weekends when buildings are mostly empty.

Periodically assessing and retooling heating and cooling systems can achieve additional energy savings. Any heating and cooling equipment older than a decade, for example, is probably ripe for an upgrade to a newer more energy efficient system. The federal government’s Energy Star program, administered jointly by the Environmental Protection Agency and the Department of Energy, rates the energy-efficiency of lighting, office equipment and heating/cooling systems from a wide range of manufacturers. Purchasing administrators can browse the Energy Star website to find out which models and systems will save a company the most money.

A handful of environmental groups are walking the talk via recent “green” retrofits to their office spaces. The National Audubon Society, Natural Resources Defense Council and Environmental Defense, for example, have installed occupancy sensors and compact fluorescent lighting throughout their offices, and in some cases have installed windows and configured their workspaces to make use of natural daylight instead of artificial light where possible.

CONTACTS: U.S. Department of Energy’s Energy Efficiency and Renewable Energy Program, www.eere.energy.gov; Advanced Energy, (919) 857-9000, www.advancedenergy.org; Energy Star, www.energystar.gov.