Benchmarking commercial energy use per square foot

How often are you confronted with the reality of your building’s monthly utility bill? If the answer is “not often” or “never,” you are 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 £50,000 per year on energy, a lack of knowledge surrounding the details of your cost means you may not have as good a handle on this major expenditure as you thought you did. In fact, most building operators do not 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.

Reversing the slow climb of energy costs, starts with gaining greater awareness of how your building uses energy. In this article, we will discuss the average commercial building energy consumption per square foot, and help you measure and compare your own usage with other buildings in your industry.

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What is the average commercial building energy consumption per square foot?

Typically, the average number of kilowatt-hours per square foot for a commercial building is approximately 22.5 kWh per year.

Here is the breakdown of how that energy is used:

• Approximately 8 kWh/square foot are consumed by refrigeration and 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 0.5 kWh/square foot are consumed by hot water heating.

Measure, benchmark and 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:

1. Measure your building's energy consumption.
2. Benchmark your building against similar buildings.
3. Make targeted improvements.

1) Measure your building's energy consumption

Numerous components contribute to energy consumption in buildings, from heating and cooling to lighting, ventilation, and more. So, while it is important to be aware of your commercial building’s energy consumption per square foot as well as its total consumption, it is 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.

By 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:

• Lighting
• HVAC
• Ventilation systems
• Hot water systems
• Heat pumps

If you are measuring a facility’s total energy use for the very first time, it is 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 will get about the specific factors that influence your consumption level.

2) Benchmark your building against similar buildings

Once you have some data of your own, you can use the industry benchmarks as a reference point. The data compiled for building energy use per square foot in various sectors is meant to be a gauge to see how well you compare. The two important questions to consider are:

a) What is the average kWh/sqaure foot for a building in my sector and how does it compare to my own building's consumption data?

b) What systems are primarily responsible for driving that energy use and how does each of your system components, like lighting or heating, 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 does not mean there are not still ways to save. To identify those opportunities, you will need to analyse your data and hone in on the specific energy-saving opportunities your building (or buildings) present(s).

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 utilise 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.

• 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 energy use per square foot - and more?

It is not as hard as you think to start monitoring your building’s energy consumption. Twinview has been developed as a browser-based platform to link IoT devices to dashboards which analyse a building’s operational data to reduce energy sorts and improve building performance.

Contact the Twinview team to learn more about our digital twin platform and how you can gain greater visibility into your building’s performance.