Taking (Building) Stock: DOE’s data on commercial buildings and lighting

Published On
Feb 15, 2022

Commercial buildings in the United States are getting larger and increasingly include energy-saving features such as LED lighting, according to the U.S. Department of Energy’s 2018 Commercial Buildings Energy Consumption Survey (CBECS).

Published in September 2021, this iteration of the survey is based on an anticipated participating population of roughly 8,000 buildings. The data was then extrapolated to produce national estimates covering a wide range of characteristics for the estimated 5.9 million commercial buildings in the United States, covering 97 billion square feet. CBECS data include number of buildings and floorspace by characteristics such as geographic region, building activity, size and age, employment and occupancy, energy sources used and energy-related equipment.

What does the data tell us?

The estimated number of U.S. commercial buildings grew by 6% from 2012 to 2018, and total floorspace grew by 11%. An estimated 357,000 buildings were built from 2013 to 2018, representing 7.5 billion square feet. The number of education, lodging, public assembly, worship, service and warehouse buildings increased, while some markets, such as food sales/service, healthcare, mercantile and office, decreased. By square footage, the largest markets were office, mercantile, education and warehouse.

With its large population, the South had the largest number of commercial buildings and floorspace, followed by the Midwest. The West came in third and is populated by buildings of the largest median size. The smallest number of buildings and the oldest in median years was in the Northeast. Some 86 million people worked in these buildings, with a median 1,175 square feet per worker, which was 14% more space than in 2012.

Seventy percent of commercial buildings were 10,000 square feet or smaller, down from around 75% in 2012.

For all buildings, the median building size was 5,400 square feet. Buildings over 100,000 square feet constituted only 2.4% of the total number of buildings, but 34% of the floorspace.

As this is a lighting column, let’s take a look at this category. The LED revolution started back in 2012. By 2018, CBECS estimates that standard fluorescent fell from lighting 92% to 76% of all commercial building floorspace. LED, meanwhile, increased from 25% to 64%. Meanwhile, in 2018, incandescent was used to illuminate 22% (down from 44%) and HID 12% (down from 27%). This is a snapshot of an extraordinary technology shift still in motion.

Lighting control adoption also increased, with the biggest winner being occupancy sensors. In 2018, an estimated 17% of commercial buildings—46% of floorspace—used occupancy sensors, up from 15% and 41%, respectively, in 2012. Daylight harvesting modestly increased from 7% to 7.5% of floorspace. Building automation systems for lighting increased from 14% to 17%.

Multilevel lighting and dimming remained flat at 15% of floorspace, somewhat surprising due to the inherent controllability of LED lighting, and suggesting some dimming for energy management was not considered in the response. For the first time, the CBECS included plug load control, which showed use in less than 1% of buildings and around 2% of floorspace.

On a related note, one of the most significant takeaways is a persistent lighting retrofit opportunity. Lighting retrofits are most profitable in buildings with older lighting systems, which tend to be overlighted and use obsolete technology. Add long operating hours and high energy rates, and the building is often a good candidate for a lighting upgrade.

The 2018 CBECS estimated the median age of all commercial buildings to be 36 years and that about 2.7 million buildings (46% of all buildings), constituting 39.8 billion square feet (41% of all floorspace), were built before 1980. CBECS estimated that 2.4 million of these buildings, representing 25 billion square feet, have not received a lighting upgrade. Interestingly, CBECS also reported a significant amount of floorspace illuminated by LED—24.9 billion square feet—suggesting that at least piecemeal upgrades, such as exit sign replacements and LED linear replacement lamp installations, have occurred. Meanwhile, the majority of all buildings and floorspace remains untapped for lighting automation, regardless of age.

There’s plenty more in the 2018 CBECS that can be used for business planning around the commercial buildings market. The lighting data alone can be parsed by building size, age, type, region, etc., providing rich insights. It’s important to note, however, that the results are estimates based on a sample population. View and interpret the results with an educated eye and remember that how some data appears depends on how the question was interpreted by DOE and the respondent.

Find the 2018 CBECS at www.eia.gov/ consumption/commercial/data/2018/index.php.

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