When the design isn't enough
Beware of the trap of building an efficient design and assuming it operates efficiently, it can be summed up in one word: drift
Let me start by saying upfront, designing for efficiency is important, as is designing to reduce the embodied carbon in that design. But what is designed versus how a building is actually operated is often quite different than you may think, for several reasons. This week let’s dive a little deeper into these reasons - and more importantly, lay out some strategies to ensure both efficient design and operations.
The bane of many a building operator is drift. To explain drift, think about your car for a moment. occasionally the oil needs to be replaced, the tires need to be rotated, and the engine may need to be “re-tuned” to stay within the expected operational performance of that vehicle (so it runs like you expect to run). Buildings are similar, in that they really are a series of systems that overtime can “drift” out of the range of the desired operation. Unlike your car, however, unless you have a building automation system, you likely do not have a “check engine light” to tell you the engine needs to be recalibrated or to alert you that someone needs to take a look at it.
The result is often building designed for high-efficiency performance, which is actually performing worse than their owners and operators realize. You want a design that incorporates all the best practices you can work into the budget. LEED Platinum - awesome! Living Building Challenge or Passive House, even better. But even these buildings after a year or two may perform much differently than designed.
The US Department of Energy’s Lawrence Berkely National Lab has researched the impact of commissioning and retrocommissioning in buildings. Study after study shows that buildings are vulnerable to equipment deficiencies and general wear and tear over time that can cause buildings to drift away from their ideal operational performance.
How much you might ask? According to a study by Texas A&M with Lawrence Berkely National Laboratory, 10-30% over a one to two-year period. That LEED Platinum Building, designed to consume 25%-30% less energy compared to conventional buildings, is barely holding its own after two years, and in three to four years without intervention may be performing much worse.
As you can imagine, a lot of research has been completed on the true energy-efficiency of LEED Buildings. A 2019 study, by Ali Amiri, Juudit Ottelin, and Janna Sorvani determines that a review of the literature around this topic resulted in inconclusive results. There was a clear advantage in the initial energy performance at delivery, but when revisited after the first two years of operation, nearly 33% of the buildings performed worse, in many cases consuming more energy than more conventional designs with less efficiency built into the design.
This is not an indictment of LEED or the USGBC. Those organizations that are building to LEED standards and verifying the design with certification are absolutely trailblazers who deserve recognition for taking an important initial step towards net-zero.
If the issue isn’t the initial design, and we have established that drift occurs over time, how can an organization make sure that they realize the returns that they are counting on? The answer not surprisingly is data. It is perhaps more critical in an efficiently designed building to monitor the actual operation so the organization realizes the returns promised by the original design. If you build it and simply walk away, point at the plaque in the lobby, and assume you have an efficient building, you may be short-changing yourself.
Guess who else realized this? The USGBC, which is why LEED 4.1 introduced the requirement of recertification of all occupied and in-use projects certified under version 4.1 three years after initial certification. Recertification requires 12 months of continuous data to validate that the performance still matches the initial design and certification.
This same process can be conducted without the costs of a LEED recertification process if the intent is to continue to realize the performance and not necessarily maintain the LEED certification. One strategy is to shift to an Energy Star Certification instead, which would be considerably lower in cost to maintain than a formal LEED recertification process. This is an organizational decision, but whichever path your organization decides to pursue, both paths still require data.
OK, so we have established you will need operational data: energy and water consumption. But you also need to know how that performance stacks up. To compare your performance, you need to understand what normal is - you need a benchmark. Something to compare against, the more robust benchmarking database used, the better the analysis. This means a bigger database - one with more buildings in it - provides more value than a smaller database. A newer database provides more market relevance than an older database. When it comes to comparing your performance against a benchmark, what your comparing against can provide a competitive advantage. The better the benchmark database, the better the analysis.
Many of us started by using Energy Star Portfolio Manager for benchmarking. It makes a lot of sense, access is free, although you do have to figure out how to get the data in and you have to do your own analysis on the results. If your working with a commercial office property, you are actually using a decent-sized database, with relatively current data. The database for commercial buildings was updated in 2018, along with the database for retail, Supermarkets, K-12, Hotel, Warehouse & Distribution Centers, and Worship Facilities. The database used is CBECS, which has started with a sample size of 16,000 buildings, although the final study narrowed that to 8,000. There are larger and more robust databases available for those organizations seeking more robust and market-relevant data.
Two building types you might have noticed are missing from that list. Hospitals, which are scheduled for an update this month. The other, unfortunately, is multifamily property. While there is a database, it is considerably smaller than what most realize. As CBECS does not include multifamily property in its building surveys, we instead rely on a 2011 Fannie Mae report Multifamily Energy and Water Market Research Survey. This data set is based on the performance reported by 1,163 multifamily properties across the United States. Of those 1,163 properties, only 672 provided both energy and water data, and another 278 provided energy only, 64 provided water data only, and 149 provided only characteristic info but no energy or water consumption data. In this case, you are looking at a very small sample size compared to the market, and the collection of that data is quite outdated. In this case, you may want to rely on a private database that has more properties and more market-relevant (newer) data.
Once you have settled on the database you are going to use to compare your data against, you next need to determine how you are going to monitor the data. Scale can become a significant issue at this stage, developing an efficient protocol that allows you to spot trends will be important. This also means interpreting the data, or energy analysis as we call at Bright Power. It takes a particular skill set to look at data, recognize the trend, and interpret the data to make it meaningful.
With data in hand, a plan to analyze it, and the skill set to conclude you can set in motion the important step of acting on the data. This may represent a work order for maintenance, a service call to diagnose a usage spike, or a capital budget request. These energy efficiency measures are what stops the drift and allow an opportunity to realize actual reductions. This is the key action item to reducing the operational expense, but notice we did not start with the action item. We started with the data, we then analyzed the data, and identified the actionable trend before we put forth a potential solution.
This is another area where portfolio managers can sometimes experience lower returns than they anticipated. Starting an efficiency project, before you identify the actual cause of the inefficiency. There are plenty of salespeople who will sell you their service, but if that service doesn’t actually resolve the root cause, the issue may persist. Once again, having data first just allows for better decisions and better focus on what the real issue may be.
We have covered a lot of ground this week, and as I said when I began this article a good design is essential for good performance. Just keep in mind, when there are moving parts, there is a potential for things to change and the original intent may be lost through drift. The key is identifying and correcting drift before you move too far away from the design.
You can help reduce the impact of the built environment by sharing this blog with your peers. Together we can impact the 39% of greenhouse gasses attributed to the built environment. It starts with awareness and we succeed with teamwork.
Stay well!
Chris Laughman is the ThirtyNine Blog author, a blog dedicated to reducing the impact of the built environment. When not blogging, Chris is helping the real estate industry reduce energy and water impact as the Vice President of Sustainability for Conservice, the Utility Experts. Whether Multifamily, Single Family, Student Housing, Commercial, or Military, we simplify utility billing and expense management by doing it for you. Our insight into your utility consumption provides an opportunity to identify risks. Leveraging innovation and experience we ignite solutions with real impacts and track performance to ensure the trendline stays laser-focused on the goal. At Conservice we have developed a true bill-to-boardroom solution to help truly make a difference. We have before us a tremendous opportunity. Standing shoulder to shoulder, we will get this done. Contact me at claughman@conservice.com for more information.
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