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Energy Use in Commercial Buildings

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from http://www.eia.doe.gov/kids/energyexplained/uses/commercial.html
Image of how energy is used in commercial buildings. Space heating uses 36%, lighting uses 21%, water heating uses 8%, cooling uses 8%, other uses 9%, office equipment uses 3%, ventilation uses 7%, refrigeration uses 6%, and cooking uses 3%. Source: EIA, 2003 Commercial Buildings Energy Consumption Survey
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Commercial buildings include a wide variety of building types — offices, hospitals, schools, police stations, places of worship, warehouses, hotels, and shopping malls. Different commercial activities all have unique energy needs but, as a whole, commercial buildings use more than half of their energy for heating and lighting.

Types of Energy Used in Commercial Buildings

Electricity and natural gas are the most common energy sources used in commercial buildings. Commercial buildings also use another source that you don’t usually find used in residential buildings — district energy. When there are many buildings close together, like on a college campus or in a big city, it is sometimes more efficient to have a central heating and cooling plant that distributes steam, hot water, or chilled water to all of the different buildings. This type of system (referred to as a district system) can reduce equipment and maintenance costs as well as save energy.

Energy Use by Type of Building

The types of buildings in the commercial sector are used for a mix of many different activities and uses. Retail and service buildings use the most total energy of all the commercial building types. This is not very surprising when you think about all the stores and service businesses there are all over the United States. Other commercial users of energy include offices, schools, health care and lodging facilities, food establishments, and many others.

Shares of Fuels Used by Commercial Buildings (2003)
Image of the types of energy used by commercial buildings. Electricity is 55%, natural gas 32%, district heating 10%, and fuel oil 3%.

Source: Energy Information Administration, 2003 Commercial Building Energy Consumption Survey (September 2008).

The top five energy-consuming building categories use about two-thirds of energy consumed by commercial buildings and include the following kinds of buildings:

  • Retail and Service (20% of total energy consumed by commercial buildings)
    • Malls and stores
    • Car dealerships
    • Dry cleaners
    • Gas stations
  • Office (17% of consumption)
    • Professional and government offices
    • Banks
  • Education (13% of consumption)
    • Elementary, middle, and high school
    • Colleges
  • Health Care (9% of consumption)
    • Hospitals
    • Medical offices
  • Lodging (8% of consumption)
    • Hotels
    • Dormitories
    • Nursing homes
from http://www.eia.doe.gov/kids/energyexplained/uses/comcef.html

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Last Reviewed: July 13, 2009


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Chart showing energy use by type of commercial building, 2003
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More site electricity is consumed for lighting than for any other end use.

Bar graph showing the use of electricity in commercial buildings in 2003. Lighting 38%, cooling 13%, ventilation 13%, refrigeration 12%, other 12%, computers 5%, space heating 4%, office equipment 2%, water heating 2%, cooking 1%
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The percentage of buildings using CFLs more than doubled between 1995 and 2003.

bar chart showing percent share of lit commercial buildings by lighting type for the years 1995, 1999, and 2003
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Nearly 4.9 million U.S. commercial buildings1 contained more than 71.6 billion square feet of floorspace in 2003. The commercial buildings sector is dominated by five building activities — office, mercantile, education, healthcare, and lodging. Together they comprise 60% of total commercial floorspace and 51% of all commercial buildings in the United States. These types of buildings also use the most energy in the commercial buildings sector.

Electricity and Natural Gas Are the Dominant Energy Sources in Commercial Buildings

Together, electricity and natural gas account for more than 87% of total energy consumed in the commercial buildings sector. Electricity consumption increased from just over 2.2 quadrillion Btu in 1979 (when the Energy Information Administration began these surveys) to more than 3.5 quadrillion Btu in 2003. Along with that increase in consumption, electricity increased its share of total energy consumed from 38% in 1979 to 55% in 2003.

Computers, Copiers, and Other Office Equipment Contribute to Increase in Electricity Consumption

The increase between 1979 and 2003 in electricity consumed is consistent with the increased use of existing types of electrical equipment and the introduction of new types of equipment in commercial buildings. These new types of equipment include computers (PCs, work stations, and servers), office equipment (printers, copiers, and fax machines), telecommunications equipment, and medical diagnostic and monitoring equipment. In addition to electricity consumed directly by these types of equipment, many of these types of equipment have cooling, humidity control, and ventilation requirements that also increase electricity consumption.

Lighting in Commercial Buildings Uses the Most Electricity

Lighting is the major consumer of electricity in commercial buildings and a target for energy savings through use of energy-efficient light sources along with other advanced lighting technologies. Nearly all commercial buildings have some type of lighting. The majority of those without lighting are warehouses and vacant buildings.

When analyzing only electricity use in commercial buildings, you can see that more electricity is consumed by lighting than any other individual end use.

Commercial Buildings Are Using More Halogen and Compact Fluorescent Lamps

The percentage of commercial buildings with lighting was unchanged between 1995 and 2003; however, three lighting types did show change in usage. Compact fluorescent lamps (CFLs) and halogen lamps showed a significant increase between 1995 and 2003, while the use of incandescent lights declined.

  • CFLs were used in twice the share of lit buildings in 2003 than in 1995, going from 10% to 20% of lit buildings.
  • The use of halogen lamps nearly doubled, from 7% to 13% of lit buildings.
  • Use of incandescent lights was the only lighting type to decline; their use dropped from 59% to just over one-half of lit buildings.
  • Standard fluorescent lamps and high intensity discharge lamps showed no significant change in use.

Commercial Buildings in the South Region Comprise More Floorspace and Use More Energy than Other Regions

The total floorspace of commercial buildings in the South was 26.7 billion square feet in 2003. Major fuel consumption in these buildings totaled more than 2 quadrillion Btu. More than $38 billion was spent on electricity expenditures in Southern commercial buildings alone.

Large Commercial Buildings Use the Most Energy Overall, Though There Are Far Fewer of Them

The smallest size category of buildings (1,001 to 5,000 square feet) accounts for 11% of energy consumption and the three smallest categories combined (1,001 to 25,000 square feet) account for one-third of consumption, but these three categories account for nearly 90% of buildings.

In contrast to smaller commercial buildings, the percentage of consumption in larger commercial buildings greatly exceeds the percentage of buildings. Less than 1% of buildings are larger than 200,000 square feet in size, but these buildings consume more than one-quarter of total energy. Only 5% of buildings are larger than 50,000 square feet in size, but these buildings account for more than 55% of energy consumption.

Nearly 40% of U.S. commercial floorspace is in the South.

Bar chart showing commercial building floorspace by region, 2003. South 26.74 billion square feet, Midwest 18.10 billion square feet, Northeast 13.99 billion square feet, West 12.84 billion square feet.
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Buildings in the South account for more than one-third of total energy consumed in commercial buildings.

Bar chart showing total energy consumption in commercial buildings by region, 2003, expressed in trillion Btu, the South consumed the most and West consumed the least.
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1. Commercial buildings are defined as all buildings in which at least half of the floorspace is not used for residential, industrial, or agricultural purposes, so they include building types that might not traditionally be considered "commercial," such as schools, correctional institutions, and buildings used for religious worship.

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Last Reviewed: July 13, 2009


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