ASHRAE Standard 100 in focus, part 1: The story behind the Standard | The Pulse by GRESB

In this episode of The Pulse by GRESB, we kick off a two-part series exploring the role of energy efficiency in the GRESB Standards, with a focus on the ASHRAE Standard 100. Host Parag Cameron-Rastogi is joined by Jamie Kono from the Pacific Northwest National Lab and Glenn Friedman of Taylor Engineering—both members of the ASHRAE Standard 100 committee. Together, they unpack how this building performance standard was developed, what it means for energy efficiency in existing buildings, and how it’s being integrated into the GRESB framework. Tune in to learn how these benchmarks are shaping the future of building performance and sustainability. Watch the episode, and listen to part two of the conversation, featuring:

Can’t listen? Read the full transcript below. Please note that edits have been made for readability.

Parag: Welcome to the Pulse by GRESB, our interview series where we discuss important topics in sustainable real assets. My name is Parag Cameron-Rastogi and I’m your host for today. We are going to be talking about energy efficiency in the GRESB Standard and beyond. To help me talk about energy efficiency today I am joined by Jamie Kono from the Pacific Northwest National Lab, based in the USA, and Glenn Friedman, from Taylor Engineers, also based in the US. They’re both members of the standards committee that has made the standard that GRESB has adopted this year called the ASHRAE 100 standard. It’s good to see you both could you please introduce yourselves briefly, Jamie?

Jamie: Hi. I am Jamie Kono. I am a research engineer at Pacific Northwest National Lab, which is a US Department of Energy National Lab. However, today I am speaking on my own behalf and according to my background as a member of the ASHRAE Standard 100 Committee.

Glenn: My name is Glenn Friedman and I’m a principal at Taylor Engineers in the San Francisco, California area. And my background is in consulting, engineering, construction, contracting, and energy efficiency work, including commissioning. So this has been a passion of mine for years.

Parag: Fantastic. Thank you both. I think first things first, what is an ASHRAE Standard? How is it made, how is it adopted? How is it maintained? And why do we often see these four letters “ANSI” at the beginning of many ASHRAE Standards?

Glenn: ASHRAE Standards covers, portions of the industry. And the governance for those portions of the industry. Now, the four letters beforehand, ANSI, that’s the American National Standards Institute, which is a governing body that assigns a portion of an industry to be controlled by a given standard.

In other words, to avoid multiple standards from multiple parts of government overseeing the same thing. When ASHRAE develops standards, they follow the ANSI protocols to get that standard adopted. Those protocols are important to make sure that it is not specific to one industry, but that it is developed in a way that takes into account all different competing industries for any type of standard. It does so in a public structure.

Parag: I’d like to point out for our international listeners, that ANSI is the US representative to ISO. For example, in Britain we have the British Standard Institute, the CEN from Europe. ISO is made up of national bodies of which ANSI is one. Staying with you for another question, Glenn, could you walk us through the origin story of ASHRAE 100?

Glenn: I’d be happy to, and you bring up an important point about it being a US standard versus an international standard. So, ASHRAE started off in developing standard 100, way back in the mid nineties, and it was developed to bring forward energy efficiency measures in existing buildings that were not otherwise undergoing building retrofits or renovations.

In other words, it recognized the importance of energy efficiency and how that was a goal into itself. Not only around retrofits and remodels, but something to be pursued by building owners. But it continued to develop over the years. So in 2009, the ASHRAE presidential address recognized that energy efficiency in existing buildings is the greatest opportunity for a sustainable future, and that reinvigorated the standard.

In 2015, a new version was revised and restructured to include energy audit requirements, performance data evaluations, and overall building lifecycle analysis. As ASHRAE went forward in recognizing themselves as an international standard as opposed to a US standard, ASHRAE Standard 100 was updated and republished in 2024 to establish it as a building performance standard to be used as a template by jurisdictions and to include not only energy, but also operational carbon targets. It was renamed as energy and emissions building performance standard for existing buildings.

Parag:  Thanks Glenn. I think it’s important to highlight, in the GRESB context, in this first version of our interaction with ASHRAE Standard 100, we are using only one part of the standard, which is the energy efficiency limits table, or targets, essentially, to score highly efficient buildings.

So, now that we’ve heard the history of it, maybe Jamie, can you talk a little bit about, where is Standard 100 going, or energy efficiency practices in general?

Jamie: Yeah absolutely. I’ll also add one of the things that has changed over time with Standard 100. Back in 2015, the committee wrestled with should we release targets, or should we leave it up to a jurisdiction or to whoever’s utilizing Standard 100 to set their own absolute efficiency targets and go forward from there. And the committee ultimately decided, well, we need that absolute level for folks to have as a target for their buildings.

Obviously no target will be perfectly applicable to every building out there. But the idea being, we have a large data set within the US feedbacks and the US RECS data for commercial and residential buildings – let’s set some targets set as our baseline. Now with that said, we have changed those targets over time. Our current targets are based off of CBECS 2012 and RECS 2015. And those are the ones that you all are using within GRESB as well.

Glenn: Let me add to that, we also recognize that ASHRAE, being an international society, needs to have targets that cover the world, climate zones that cover the world. And we realized that the organizations that might adopt Standard 100 will take either portions of it or all of it in different ways.

We also started to explain further details of how individual jurisdictions could adopt their own energy targets based on their building stock. Hopefully, that opened it up to an international audience being able to look at it and say “Well, the US building stock may not represent our building stock, but here is a template to explain how energy data can be used to develop these same types of local energy targets and emission targets for buildings”.

Jamie: And I think there’s a potential in the future to expand targets to be based on more international data sets. Also in our 2024 release of Standard 100,we expanded the targets available from just climate zones that are in the US to climate zones across the entire globe.

Parag: So the current benchmarks or the thresholds in ASHRAE 100 standard, the ones that are being implemented in GRESB at the moment are based on EUI, energy use intensity, which is the energy use per square meter of area or per square foot of area. Obviously, one metric can’t be universal. How do you envision adapting these metrics to sectors that are not easily defined by EUI like hospitality, hospitals, industrial manufacturing, storage. Could you comment on that?

Jamie: So I am the chair of a working group that’s focused on maintaining the performance targets within Standard 100. So We’ve got, some great discussions happening around how to make these targets better, how to make them more relevant to two different building types. One of the inquiries is: how can we come up with more advanced normalizations or performance metrics that we can use to establish targets? We don’t want to get too complicated, because we want this to be relevant to a large portion of buildings and we want it to be accessible and not require advanced modelling or data analysis. Currently within Standard 100 we have one normalization parameter – an operating hours multiplier. We determined that if a building is 24/7 versus say 40 hours a week in operation versus, 120 hours a week operation, the building’s going to have an EUI within it, based on the usage pattern of the building.

We’ve considered other factors such as some proxy, or indication of the occupancy of a building. For example, a super dense call centre is going to have a lot more energy used and a lot more plug loads and people in it than say, a very spread out lawyer’s office that has half the people density or maybe a 10th of the people density of some other office space. We want to make sure that we’re addressing any major differences between usage and certainly want to make sure that we’re representing buildings in a way that’s not problematic or not penalizing them for additional performance, or additional productivity.

Parag: You bring up a couple of interesting points there, Jamie, because this is a very live discussion at GRESB. The issue that comes up quite a lot is utilization. As you correctly pointed out, the operating hours concept is a good proxy. There’s also the idea of how much the building’s actually being used, how many people are coming in and out? How many units are you renting out? These are not things we currently track in GRESB. But it’s something that’s certainly on our mind.

EUI is not the only metric there is in the world, and there are other ways of looking at buildings, which, I think, is a very useful way to think about this evolution of the GRESB Standard. We’ve got a new data centre assessment coming out because we realize data centres are such a different type of building that they don’t conform to most of the rules we’ve set for buildings. What is the top priority right now in terms of different advanced metrics you’re looking at?

Glenn: That’s a very good question, and the committee has been using data that has been collected based on CBECS and RECS, the Commercial Building Energy Survey and Residential Building Energy Survey. And since that was the available data, the original template was built off of an EUI and energy utilization per area. But it’s also been a topic that has been continuous in ASHRAE Standard 100 about what are the other metrics that we should be exploring and using? We actually have a research topic that we’ve been developing to specifically look at what’s available and out there that could be used to represent buildings beyond the energy utilization index.

So, if it’s manufacturing the number of components that are being built, there was some research on airports that showed that it was less about the users in the airport as it was about the number of mechanisms within the airport for people movers for equipment movement, et cetera. So we are trying to develop what are the different aspects. But also, how do we do that in a way that’s manageable? We don’t want to get so much data collection that it’s unusable, but we do want to represent many different types of buildings out there.

Jamie: When we get really into the nitty gritty of how a target will affect specific buildings, I like to bring it back to the fact that this is an existing building standard. It’s meant to essentially provide guidance for whether one needs to do extra investigation into their building.

So, the framework of Standard 100, encourages you to look at the building, its measured performance, and then decide, whether you need to do some kind of assessment and if you need to take action on that assessment to improve its performance. However, there are buildings that once they’ve done plenty of assessments and made plenty of updates, well they don’t really need to go through that process again. I think the beauty of Standard 100 targets is that essentially, you can kind of stop looking as long as you keep maintaining that high level of efficiency. You’re good to go – let’s focus your energy elsewhere on other buildings that you can improve further.

Parag: Most of the people who are actually submitting to GRESB are often dealing with multiple buildings. They have portfolios to deal with. So this approach makes a ton of sense, don’t focus on the buildings that are just consuming a small amount of energy. Focus on the larger magnitude issues first.

With that, we come to the end of part one of this two part series about ASHRAE Standard 100 and it’s use in GRESB. Thank you very much to Jamie and Glenn. To the listener, if you’d like to hear more about what’s in the standard and where it’s going in the future, please come back for part two of this episode.