Small and Midsize Offices

Small and midsize office buildings in the US (those under 100,000 square feet) use an average of 15 kilowatt-hours (kWh) of electricity and 38 cubic feet of natural gas per square foot annually. In a typical office building, lighting, heating, and cooling represent nearly 70% of total energy use (Figure 1), making those systems the best targets for energy savings. Energy represents about 19% of total expenditures for the typical office building, making it a significant operational cost deserving of management attention.

Average energy use data

Figure 1: Energy consumption by end use
National data indicates that ventilation, computers, and lighting are the main electricity end-use categories in small office buildings, and that space heating dominates natural gas consumption.
Pie chart showing electricity end uses: Ventilation, 26%; Miscellaneous, 25%; Computer, 19%; Lighting, 17%; and Cooling, 13%.
Pie chart showing natural gas end uses: Heating 87%; Water heating, 7%; and Miscellaneous, 6%.

In order to better manage your building’s energy costs, it helps to understand how you are charged for those costs. Most utilities charge commercial buildings for their natural gas based on the amount of energy delivered. Electricity, on the other hand, can be charged based on two measures: consumption and demand (Figure 2).

Figure 2: Load profile for a typical California office building
Hourly energy consumption data show that lighting and cooling present the largest opportunities for reducing peak demand charges in office buildings.
Figure 2: Load profile for a typical California office building

The consumption component of the bill is based on the amount of electricity, in kWh, that the building consumes during a month. The demand component is the peak demand—in kilowatts (kW)—that occurs within the month or, for some utilities, during the previous 12 months. Monthly demand charges can range from a few dollars per kW to upwards of $20/kW. Because these demand charges can be a considerable percentage of your bill, it’s important to take care to reduce your peak demand whenever possible. As you read the following recommendations for energy-cost management, keep in mind how each one will affect both your consumption and your demand.

The conservation measures discussed here represent good investments. Most will not only save money but will also enhance both the aesthetics of your office and the productivity of your workers.

Quick fixes
Longer-term solutions
Content last reviewed: