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ASHRAE Standard 211 – Commercial Building Energy Audits has arrived!

I can’t tell you how happy I am that I can say that ASHRAE Standard 211 – the world’s first comprehensive standard for energy audits – is out!

This news might come as a surprise to some – most people treated the energy audit levels defined by the standard, as if it already was a standard. The problem was that the original publication that popularized the terms ASHRAE Audit Levels 1, 2 and 3 wasn’t a standard at all. So it left a lot of room for interpretation.

The ambiguity caused a lot of problems for cities and building owners who wanted to use the levels as a means of setting a scope of work. The original publication offered guidance, and some great information on best practices, but too much leeway made setting a scope of work ambiguous. We needed the standard to eliminate the ambiguity and clarify the level definitions beyond interpretation.

The Long Road to Standard 211

I’ve been working on this standard for the last 5 years so the release is both a professional victory and personal liberation. Professional victory because it has been a long, hard road with a lot of hours in committee, drafting approaches, and trying to draw consensus through a public review process that wasn’t designed to accomplish anything fast. And it’s a personal liberation because the responsibility of getting this thing done is out of my court. So “hooray” and “whew.”

Many, many kudos to my awesome compadres on the standard committee for sticking with this to the end. I was fortunate to have a great group of folks with whom to work. The standard is better as a result of input from committee members and everyone who contributed through the public review process.

ASHRAE Audit Levels 1, 2 and 3 – what’s changing?

The biggest change between the standard and the prior publication (Procedures for Commercial Building Energy Audits, aka “the green book”) is that, now it’s a standard. That means it sets the minimum bar for an audit to be called an “ASHRAE Level X Audit”. It’s no longer a “best practice” document.

The shift from best practice to standard is a big one. It’s one we had to remind committee members and parties involved in the public review process many times. The “green book” will continue to offer guidance on best practices. Currently a rewrite/update is underway to make it a good companion guide to standard 211.

Here are some of the changes you can expect between the green book and standard.

Level 1 is Now Largely Qualitative

Level 1 has always been tricky because the prior guidance asked for energy savings (i.e. numbers) for no-cost and low-cost measures. It’s very hard to maintain the limited scope that is intended in a Level 1 if you start doing calculations. So in the standard we made it clear that energy efficiency recommendations for Level 1 are purely qualitative, and only require the auditor to assign “high”, “medium”, and “low” to the measure savings, cost, and priority.

The only analysis that will be required is to total up historical energy consumption and benchmark the site. This avoids the potential complication of having to assign numbers to savings, costs and paybacks. That’s something which was always intended to be reserved for a Level 2 approach before you can hang your hat on it.

Level 2 Has a Quality Control Step Built In

Level 2 is what most people expect when they ask for an energy audit. It requires site specific recommendations, costs, savings and economics. It also includes important background details that help the owner determine that the auditor: 1) understands the building, 2) understands the energy costs at the site and, 3) provides a solid description of recommended measures. In short, the audit should provide the owner the guidance they expected from an energy assessment.

One of the things I’m happiest about which the committee thought of is now a Level 2 energy audit requires a basic QC check of your numbers. The reporting forms require the auditor report energy savings as a percent of the base case energy use of the primary fuel the measure impacts. Essentially it requires the most basic level of quality control – how do my savings numbers compare to the base case energy use?

Most well-qualified energy auditors already do some version of this check. This requirement eliminates the worst offending energy savings estimates – where the measure saves more than the base case use! The approach also “flags” measures with very high savings estimates as something to double check.

Level 3 – Project Development & Minimizing Risks

Level 3 has always been hard to define. I’ve heard people refer to it as “investment-grade” but I resist that term. It would be presumptuous of a committee of engineers to try to determine what meets a building owner’s investment criteria. Those criteria vary a lot depending on tolerance for risk, economic criteria, and the value of so-called “non-energy benefits” (what the rest of the world calls simply “benefits”). I prefer to think of a Level 3 as beginning project development and seeks to minimize risks.

The level of effort required in Level 3 begins to add real cost to the project. So it’s a step that you wouldn’t normally take unless you’re pretty sure the measure(s) look compelling. In the standard we require the auditor provide a schematic diagram of the installation, with an exception for “like-for-like” replacements. This is essentially another quality control check to ensure the proposed project fits the physical requirements of the facility. This step may cause the auditor to ask questions they hadn’t previously considered carefully such as; “will the boiler fit through the door?”

In the standard we also require a higher level of technical rigor and savings estimates which need to be based on measured values or hourly simulations. We also require a simple analysis of variance in key assumptions. This analysis can help the owner realize just how dependent the cost justification for a project is. For example, if the analysis depends on an energy price escalation of 2 or 3% (not uncommon in solar PV proposals btw), and the economics “go south” when that assumption is lowered to 0 to 1%, it might cause the owner to reconsider.

Reporting Formats are Online

At the request of cities who intend to adopt the standard, the committee included “normative” (i.e. required) reporting forms as part of the standard. As adopters of the standard it will be up to the Authority Having Jurisdiction (AHJ) as to whether they use those forms or something similar in their requirements. However, we hope these forms can be standardized which would help keep costs lower since auditors would by using the same reporting format for all clients. However, this section is the hardest one to gain consensus. I expect there to be some changes in the forms moving forward.

For this reason the reporting forms will be shared online, not as a CD within the Standard 211 publication. That way the committee can make and publish updates easier, and possibly more frequently than we otherwise could. While we did the best job we could of making those forms universally applicable, I anticipate that changes and updates will be needed.

Easier Data Transfer with BuildingSync

One of the optional parts of the standard that I’m very excited about is our collaboration with the developers of BuildingSync as a means of transferring energy audit data between different platforms and applications. BuildingSync is “A standard language for commercial building energy audit data that software developers can use to exchange data between audit tools.” ( To emphasize, it’s a language, not a tool.

The good folks at NREL have already built a tool that takes the data from our required forms, and interprets it into BuildingSync-compatible code. This will help enable fast and easy data transfer using tools like Asset Score that many cities are using as the reporting platform for mandatory audits. Once you’ve uploaded your audit data and building characteristics in Asset Score, you can then output some of that data into a draft building model for OpenStudio.

Our hope is that BuildingSync might help enable better transfer of energy audit data. Wouldn’t it be great if that data were available for analysis, rather than sitting in PDFs and spreadsheets all over the country? For more on BuildingSync, see our prior post on the topic.

What Next?

I’m very keen to hear the industry’s reaction to standard 211. I hope that you’ll check it out and let us know what you think.


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