How often are you confronted with the reality of your building’s monthly utility bill? If the answer is “not often” or “never,” you’re like many other facilities managers who do their best to use energy wisely, but rarely get a close look at the actual costs associated with their efforts.
In light of the fact that the average office building spends an excess of $30,000 per year on energy, a lack of knowledge surrounding the details of your bills means you may not have as good a handle on this major expenditure as you thought you did. In fact, most building operators don’t have deep visibility into where and how a facility’s energy is consumed, nor do they understand or know the pattern of use. That means your utility bill could be creeping up slowly, month by month, without your knowledge.
If you’d like to reverse that slow climb, you’re in the right place. It all starts with gaining greater awareness of how your building uses energy. In this article, we’ll discuss the average commercial building energy consumption per square foot, and tell how to measure and compare your own usage with other buildings in your industry. Let’s get started.
Interested in ways your building can save money through greater energy efficiency? Ask us about our smart building solutions.
What’s the average commercial building energy consumption per square foot?
According to the Department of Energy (DOE), the average number of kilowatt hours per square foot for a commercial building is approximately 22.5.
Here’s the breakdown of how that energy is used:
- Approximately 8 kWh/square foot are consumed by refrigeration & equipment.
- Approximately 7 kWh/square foot are consumed by lighting.
- Approximately 3 kWh/square foot are consumed by cooling equipment.
- Approximately 2 kWh/square foot are consumed by heating equipment.
- Approximately 2 kWh/square foot are consumed by ventilation.
- Approximately .5 kWh/square foot are consumed by hot water heating.
Average Commercial Building Energy Consumption
While the question of commercial building energy consumption per square foot is a popular one, it’s not quite the one you should be asking. Buildings house different types of operations, and therefore have different energy profiles. Energy use in office buildings, for example, focuses on creating a comfortable, healthy, optimal environment for workers; its energy expenditures are mainly on things like lighting, ventilation, and air conditioning. In contrast, a food manufacturing facility’s primary energy expenditure is related to its production processes; as a result, its energy needs are primarily focused on things like steam systems, ovens, furnaces, refrigeration units, and more, all of which comprise the largest portion of this sector’s energy consumption.
So a more appropriate question would be, What is the average building energy use per square foot for a building in my industry?
The Department of Energy also examined energy intensity by industry and created a chart listing the average kWh per square foot. Of the 17 industries examined, here are a select few:
- A food service facility consumes approximately 56 kWh/square foot.
- A retail mall consumes approximately 23 kWh/square foot on average.
- A public assembly building consumes approximately 15 kWh/square foot.
- A warehouse consumes approximately 9 kWh/square foot.
In addition, to help you better understand what activities are associated with that energy usage, the DOE has further broken down overall average electricity usage per square foot for commercial buildings into the average amount spent per system—i.e., lighting, heating, cooling, ventilation, etc.
For example, the average manufacturing facility’s energy consumption is broken down like this:
- Approximately 10 kWh/square foot is consumed by lighting.
- Approximately 9 kWh/square foot is consumed by refrigeration & equipment.
- Approximately 5 kWh/square foot is consumed by heating.
- Approximately 3 kWh/square foot is consumed by cooling.
- Approximately 2 kWh/square foot is consumed by ventilation.
Manufacturing Facility Energy Consumption
Here’s what the breakdown looks like for a retail building:
- Approximately 9 kWh/square foot are consumed by lighting.
- Approximately 5 kWh/square foot are consumed by refrigeration & equipment.
- Approximately 3.5 kWh/square foot are consumed by cooling.
- Approximately 2 kWh/square foot are consumed by ventilation.
- Approximately .75 kWh/square foot are consumed by heating.
- Approximately .25 kWh/square foot are consumed by hot water heating.
Retail Mall Energy Consumption
Measure, Benchmark, & Reduce Your Energy Use
Benchmarking is important, but actually producing a change in your utility bill requires that it be done as part of a three-step process:
- Measure your building’s energy consumption.
- Benchmark your building against similar buildings.
- Make targeted improvements.
1) Measure your building’s energy consumption.
As the data above makes clear, numerous components contribute to energy consumption in buildings, from heating and cooling to lighting, ventilation, and more. So while it’s important to be aware of your commercial building’s energy consumption per square foot as well as its total consumption, it’s also valuable to know how individual components of the building are contributing to those numbers. Only then can you truly benchmark your building’s performance, and identify specific areas that need improvement.
The Internet of Things (IoT) makes it possible to gain a more in-depth understanding of your facility.
Using wireless IoT sensors placed throughout your building, you can collect real-time, detailed information about your commercial building’s energy consumption per square foot. These sensors can be used to monitor various operations remotely, including:
- Individual machinery
- Lighting
- HVAC
- Ventilation systems
- Refrigeration units
- Hot water systems
- Heat pumps, and more
If you’re measuring a facility’s total energy use for the very first time, it’s a good idea to deploy sensors in such a way that they cover the entirety of your building; the more data you have, the more insights you’ll get about the specific factors that influence your consumption level. Or, some building managers choose to place IoT sensors in areas where they’re likely to have the most impact—on known power-hungry machinery, for instance, or on HVAC equipment. Either way, having greater visibility into your current energy consumption and building environment is the key to knowing where—and how—to improve.
2) Benchmark your building against similar buildings.
Once you have some data of your own, you can use the industry charts above (or those in our Energy Benchmarking Report) as a reference point. The data compiled for building energy use per square foot in various industries is meant to be a gauge to see how well you compare. The two important questions to consider are:
- What is the average kWh/square foot for a building in my industry and how does it compare to my own building’s consumption data? If you’re in the lodging industry, for instance, does your energy use and profile align with that of other comparable buildings?
- What systems are primarily responsible for driving that energy use? How does each of your system components, like lighting or refrigeration, compare to the industry standard?
This activity may reveal a need for improvements; or, if your building is below the industry mean in terms of energy intensity, you may be doing well already. But that doesn’t mean there aren’t still ways to save. To identify those opportunities, you’ll need to analyze your data and hone in on the specific energy-saving opportunities your building (or buildings) presents.
3) Based on the results of Step 2, make targeted improvements.
The more you understand where energy is being consumed, the better you can develop approaches to cut that energy cost. Traditionally, building managers were limited in their ability to control energy use because there was no way to know exactly how a building’s power-sourced systems were performing. The best they could do was utilize building management systems to do things like turn the lights off at a certain hour or maintain predetermined room temperatures.
Today, the availability of real-time data from IoT sensors gives facility managers precise control over how their buildings use energy. For example:
- If data indicates high kilowatt hour-usage from traditional light bulbs, you could begin transitioning your light fixtures to LEDs. EE Reports estimates that the cost of a $400,000 retrofit, for example, could yield a two-year payback, and save $200,000 a year in operating expenses moving forward.
- If data indicates that your ventilation system uses a lot of energy, you could implement a demand control ventilation system. Rather than ventilating on a standard schedule, CO2 sensor monitoring can be used to ventilate only when it becomes necessary to improve the indoor air quality. As a result, your heating and cooling units use a minimal amount of energy—a strategy that can produce anywhere from 15% to 20% savings on your energy bill.
- If data shows unusually high energy use in any single building system, it may indicate repairs are needed. One company’s use of IoT sensors revealed a broken refrigeration unit; fixing the problem saved more than $115,000 annually.
Want to get started benchmarking your building’s average energy use per square foot—and more?
It’s not as hard as you think to start monitoring your building’s energy consumption. IotaComm has designed and implemented energy monitoring and efficiency programs for numerous Fortune 100 clients, and we can do the same for you. Using our line of IoT sensors and our advanced analytics platform, our knowledgeable team will help you design a remote monitoring program that’s right for your facility and your energy goals.
Visit our website to learn more about our smart building solutions, or get in touch to ask us a question about how you can gain greater visibility into your building today.