Carbon Footprint of Commercial Buildings

Human carbon emissions is causing more wildfires and extreme weather events, and 15% of U.S. emissions is energy use in commercial buildings. You can help reduce carbon footprint of commercial buildings.

Julie Smith, 8/21/26

This is a summary of Chapter 21, Energy in Commercial Buildings, in the book, “2050: What’s it Gonna Be?”.  You can download the full chapter, as well as other chapters.  References are here.

Commercial buildings are basically every type of building that isn’t a residence or factory.  Anything from a store to a school to a hospital to a restaurant to a grocery store to a football stadium to office buildings to hospitals to government and municipal buildings to data centers falls into this hugely varied and widespread category.  This category, unlike food, residential energy and transportation, isn’t directly driven by personal decisions, but rather by owners and managers of commercial buildings. 

The quantities of CO₂ emissions from this building category is similar to residential, and the principles of reducing emissions through reducing energy are similar.  The main difference is that each of us can make a difference in the residential emissions with our daily choices of how we use energy, while commercial buildings are largely dependent on decisions that each of us may have little direct control over.  However, with commercial facilities, there are ways that individual choices, community action and government regulations can help.

Water and wastewater treatment plants are technically part of the commercial building sector, making up about 10% of it.  I am including them in this discussion because they are significantly different from typical buildings, although it can easily be argued that there really is no “typical” commercial building, since they all have widely varying functions.  All-in, water treatment facilities account for 1.4% of our carbon emissions in the U.S., and, is one type of commercial facility that we can impact with our personal daily choices, because we can choose how much water we use, as one example.

Figure 1 shows a breakdown of electricity usage for commercial buildings.  The largest piece of the pie is the “all other uses”, which reflect the variety of electrical equipment that can be found in different facility types, such as hospitals, with diagnostic equipment like X-Ray machines, Ultra-sound and CAT scanners, or airports with extensive conveyance systems.  Warehouses, which also fall within the commercial sector, are likely to have conveyance equipment as well as forklifts.  Restaurants will use electricity for cooking, big office buildings and hotels will have transformers, elevators, escalators, laundry machines, computers and coffee brewers.  With water treatment plants it's all about the massive distribution pumps, while with wastewater treatment it's the gigantic air blowers. You get the idea.

Similar to residential buildings, commercial buildings use natural gas mainly to heat buildings and water, and restaurants use it for cooking.

Data centers are a steadily increasing demand on electricity and water, and are an example of emissions that individuals impact daily, similar to water, that doesn’t show up on residential metrics directly.  When we use the internet, it may feel like magic, but it’s not.  There’s a file server in a data center cranking away somewhere every time we query, stream, game or send an e-mail.  And it’s not trivial.  In 2020, data centers in the U.S. consumed 73 billion kWh of electricity, emitting 29 mmt of CO₂e,² which works out to about 0.4% of our gross emissions.   The data centers also consumed 136 billion gallons of water. 

It turns out that when we query on Google, which is how I researched a lot of this book, matters.  And even though a file server is cranking away somewhere, pulling the carbon emissions information from the EPA website, for example, is much better than the way I would have done it 20 years ago, which would have been by ordering a copy of the 800 page annual report.  The comparison below shows that Chat searches consume about 10 times the energy of a plain old Google search, and AI consumes 30 times as much.

·       Google Search:  0.3 – 0.5 Wh (watt-hour)

·       Chat GPT:  3 Wh

·       Artificial Intelligence (AI):  9 Wh

Microsoft went so far as to shove AI in my face as the default search platform in a recent upgrade of my laptop, even though I was perfectly happy with Google.  Since I know that AI uses 30 times as much energy as a basic query, I was furious when that happened, and immediately tried to get rid of it, but the “help” (that didn’t help at all) said that it was not possible to turn it off.  I finally read in a news article that I can stop it by following my query with “-ai”.  I wonder how many users will somehow find out about that little secret tip, and then actually bother to do it every time?  Does it feel like they’re trying to dumb us down on purpose?  It does to me.  And, I shudder as I wonder what they’ll think of next.  All this pressure on the consumer to satisfy the endless greed of the data center owners while increasing energy consumption unnecessarily.

I now use DuckDuckGo as my default search engine, because they actually have a setting to allow consumers to turn off AI. When I do a search, it pulls up a link to Wikipedia instead. Now how easy is that?

The utility that supplies our electricity in the Colorado front range is trying to figure out how to get funding to provide for a growth of 20% of electricity in the next few years, mainly driven by data centers.  You have to be kidding me.  Data centers?  At a time when we should be reducing our electricity?  My input on that particular issue is similar to many other renewable energy activists.  New construction of that magnitude should be required to provide their own power, and it should be required to be renewable.  Simple end of story.  As consumers, those of us who care about our planet have the responsibility to provide public comments at state and utility commission hearings. Our voices really do matter, and it's typically as simple as pushing a button and adding your name. You can get on a mailing list for an organization in your state that advocates for the planet, and they'll keep you up to date on actions, so you don't have to put a lot of time into it. This is a really simple form of activism that really makes a difference.

The idea of incorporating renewable energy into all new construction isn’t really new.  The National Renewable Energy Laboratory (NREL) here in Golden estimates that rooftop siting of solar panels could provide about 40% of current electrical demand.  This would be even higher if solar panels were also installed over parking lots that are already occupied, and the cost wouldn’t be more than 5 – 10% of the building cost for new construction.  Obviously, once installed, the building would be energy-independent, with no utility bills, so the added cost would pay out fairly quickly, in just 5 – 10 years for commercial buildings.³ 

Given that commercial facilities are about half of our electricity, this direction would reduce U.S. electricity by 50% by definition in the next 30 years, assuming the number of facility square footage doesn’t change, and new buildings replace obsolete ones.  Obviously, this is only possible if we stop growing our population.  The energy is more efficient when it’s generated locally, because there are no transmission lines, and the building is less likely to lose power in a storm.  As individual citizens, our role is to insist on these kinds of actions for commercial and industrial facilities going forward.  As discussed in Chapter 19, numerous cities and towns are pushing for change in this very positive direction.  For my part, I’m fighting against additional data centers in Colorado that draw from the grid.  They should be required to be powered with their own renewables.  And, in a dry state like ours, they should also be required to figure out their water source without demanding any more, because we don’t have enough as it is.

Water and wastewater treatment plants, which are part of commercial energy, comprise 1.4% of gross carbon emissions in this country.  The electricity includes all the raw fuels to generate it, as well as mining energy, transportation and transmission, as well as manufacturing of renewable energy equipment and components.  The natural gas includes the energy for pipeline transmission as well as the energy to produce the gas.  The land includes the actual land that the treatment plants require, as well as the estimated 1.5% of landfill space for sludge,⁴ its anaerobic decomposition in landfills, and the transportation of dewatered sludge to either landfills or composting facilities, as well as the aerobic decomposition of the sludge in composting facilities. As consumers, we do have some influence on water and wastewater carbon footprint, simply by reducing our water consumption, which also reduces our wastewater. We can also consume only products made with natural, organic ingredients for personal hygiene and home cleaning, in order to avoid adding to energy requirements for wastewater plants to treat the toxic products laced with petrochemicals that we commonly use currently.

At the end of the day, commercial energy is something that hits everybody’s carbon footprint in the U.S., sort of like construction.  So, do all of us eat our share on our CO₂e emissions metrics?  It’s a valid point, because even though as individuals we don’t have much say in how energy is used in commercial buildings, whether it’s used responsibly, whether the building is a Leadership in Energy and Environmental Design (LEEDS)⁵ compliant building or a drafty old building owned by a slum lord with no insulation in the walls.  As consumers, we can at least pick and choose who to do business with, and stay away from obvious losers, hoping that by not giving them our dollars, if enough of us say away they’ll eventually go out of business and somebody more responsible will take over.  And, as mentioned earlier, each of us can insist that new construction, including commercial facilities, meet sustainable building standards and provide their own power supply as part of the construction.  That should be a no-brainer that would certainly turn things around on our planet if it takes hold.

A new organization in Golden, Colorado, has created a website to allow consumers and particularly travelers, to choose more responsible businesses when they come to Golden. Once the Golden app is completed, they will move to other cities, with the ultimate goal of providing sustainability information for every city in the U.S. Now, how cool is that? If you're coming to Golden, check it out. It's called Go Good Travel. Also, the Colorado Department of Public Health and the Environment has a Green Biz certification, where consumers can look up responsible companies. Again, if you're doing business in Colorado, you can use these resources to choose responsible businesses to spend your money with locally. If your state has these kinds of resources, look them up and leverage them. If it doesn't, ask them to start working on this. It's important. It's our planet.