Christoph Lohr: Welcome to The Authority Podcast: Plumbing and Mechanical. When talking about the built environment, we would do well to remember: We shape our buildings, and afterwards, our buildings shape us. Therefore, on each episode, we’ll discuss the latest trends from IAPMO in plumbing and mechanical safety, sustainability and resiliency. Join me, your host, Christop Lohr, and together we’ll explore the ways we can make our buildings shape us for the better.
And welcome back to The Authority Podcast: Plumbing and Mechanical. I’m your host, Christoph Lohr, and I’m really excited to have two fantastic people joining me on the podcast today. First off is Kelly Cunningham, manager, codes and standards, with PG&E. Welcome to the podcast, Kelly.
Kelly Cunningham: Thank you. I’m so happy to be here.
Christoph Lohr: We’re happy to have you here. Also joining us is Steffi Becking, associate director with 2050 Partners. Steffi, so glad you were able to carve out some time for us.
Steffi Becking: Excited to be here.
Christoph Lohr: Excellent. Well, for our listeners, we’ll go Kelly and then Steffi. Can you just provide a brief introduction for our listeners about yourself and the organizations you work for?
Kelly Cunningham: Sure, I’ll kick it off. At Pacific Gas and Electric, within our energy efficiency team we have a small but what I like to think is a mighty team of people working on appliance and building codes and standards. We focus mainly on energy but we cover a lot of different building systems, so we do a lot of work advocating for change in standards that will inform how the future of our built environment works.
Christoph Lohr: Excellent. Steffi?
Steffi Becking: And I'm Steffi Becking with 2050 Partners. I have been involved with code advocacy work, building codes, supply and standards work, since 2015, supporting California investor-owned utilities in this arena. We do this through technical assessments and stakeholder engagement.
Christoph Lohr: Excellent. So glad to have you guys here, and thank you for the introductions. For our listeners, I think the subject for our podcast today is going to be a very exciting adoption — speaking of codes and standards adoption — and that is the Water Demand Calculator, also known as the WDC. Officially, it’s been adopted in the intervening code cycle in the state of California and goes into effect on July 1st of 2024, so this year. First question for you, Kelly, is, we’ll start with why here? Why is the Water Demand Calculator adoption in California an important event that people should be aware of?
Kelly Cunningham: Well, it’s going to provide an alternative way to add water delivery service in buildings, in new buildings. In California, many people know we struggle with water issues and our snowpack really informs how the year is going to go. After many years of drought we’ve had some relief recently, but water is such an important topic. And even though the majority of my work is about energy, making sure that we’re also looking at that energy used to deliver water and the water use itself is essential.
And when Steffi and her team brought this really great opportunity forward to change something that had been in place for decades that was ready for an update, I thought this is a great fit with our work.
Christoph Lohr: And so if I’m understanding correctly, Kelly, the Water Demand Calculator is one of those potential water-conserving and energy-conserving opportunities out there.
Kelly Cunningham: Not only that, but it also reduces material use, which addresses issues like embodied energy and carbon that is inside those building materials we use for new construction projects.
So reduce materials, reduce water use, and really take a look at how much water people are using today and how that differs from assumptions from awhile ago.
Christoph Lohr: Excellent. Excellent. Well, obviously, I’m assuming it wasn’t just a quick overnight thing to make happen. Steffi, can you tell us maybe a little bit about the story of adoption for our listeners just so they can kind of understand all the steps of what happened?
Steffi Becking: Absolutely. Yeah, it took about exactly two and a half years from the point when we started to advocate for adoption into the California Plumbing Code to the point when California Building Standards Commission said yes, we adopt.
In code update cycles it’s not a long time, but it’s certainly not overnight. And when I joined 2050 Partners in early 2021, this project on getting the Water Demand Calculator adopted in the California Plumbing Code was one of my first projects that I was asked to take on. Basically right off the bat, Gary Klein, who was instrumental in this work, and I quickly figured out that we just missed the window to submit the proposal during the regular triannual code update cycle.
California basically updates its building codes in a three-year cycle, and then there is also an intervening code cycle that takes place in between the regular trading cycles. While the intervening code cycle is meant for minor updates for building codes, it was nice for us because this proposal is already in a model code and so it was a good fit to go after that one.
We missed the opportunity to go out during the regular code cycle, but we still engaged in that code cycle. We submitted a comment later to regulators just to queue up this proposal. And then when that new opportunity opened up for changing the California Plumbing Code, enough people knew that we want to do it and so it was there to be considered.
Christoph Lohr: Excellent. Were there any stakeholders or interesting conversations you had in the process in terms of that adoption?
Steffi Becking: Yes. I would say the most impactful and most important conversation we had was early on, we got connected to the right people at the California Building Standards Commission, and I want to shout out big kudos to them because they gave us a very clear explanation of how the process works and what is the most effective way we can be part of that advocacy adoption code update process. And so that’s when we learned about a petition process and that our proposal would be a good fit for this administrative way to get an idea in the regulators’ sort of agenda. And so that’s what we leveraged and that’s what I think helped us to really be effective in getting this through.
Christoph Lohr: Excellent. Excellent. Well, kind of going back to the why of things, and I think I’ll point this question back at you, Kelly: What are you most excited about with the Water Demand Calculator? And I'll start with Kelly, then Steffi, would love for you to add to that.
Kelly Cunningham: Well, the ability to right-size pipes for water delivery; that’s been out there for a little while. But in California, local jurisdictions would have to go through kind of a lengthy city council process to be able to use this and part of my work is to work with cities who do what’s called reach codes — and elsewhere in the U.S., stretch codes — that go beyond the base state code. But this adoption where Appendix M, the Water Demand Calculator, will be in that main state code, it eliminates that lengthy city council process. That’s going to save cities time and money and it’s going to allow more access to this across the state and normalize it as a potential building practice.
That, for me, is great. Working in code interventions, I often have to do analysis and deliver news that there could be a little cost increase in order to do the right thing on the sustainability side or to protect energy bills for customers long term. But in this case, I’m most excited that it will be statewide and that there’s actually a cost reduction in terms of building properties using this new method.
So there’s water savings, there’s energy savings and there’s cost savings for builders; that is really cool. So those are the kind of four reasons that I am thrilled this project is finally bearing fruit.
Christoph Lohr: Excellent. Steffi, what about you? What are you most excited about?
Steffi Becking: Well, I’m excited that I happened to be involved in this just as this industry is ready for a change. And that turns out to be very rare. It took almost 80 years since Roy Hunter developed the Hunter’s Curve and that became the standard design practice. Now, almost 80 year later, the Uniform Plumbing Code gets into the model code Appendix M right with the new alternative way to the water demand that impacts pipe sizing. So that’s a long time in between, and prior to getting involved in the advocacy work on building codes and appliance standards, I spent a number of years in the software development industry, and there it’s agile development, it's being nimble, it’s being responsive; you constantly adopt and adapt to changes out there. The plumbing industry is the opposite — the opposite of nimble. So I am very excited that I happened to stumble into this industry just as there’s this big change happening.
Christoph Lohr: Excellent. Well, and that kind of leads me to another question for you, Steffi, which is, as you mentioned, just in my experience working in the engineering consulting realm, and engineers being very risk averse — I think that many in construction are risk averse. For good reason, we want to focus on safety and making sure things work.
But when it comes to utilizing a new third-party standard even, there’s oftentimes some concerns and probably some objections. I’m assuming there were some objections that you encountered, Steffi, in all of this. What were those objections and how were they overcome?
Steffi Becking: We talked to a lot of people and a lot of different stakeholders involved in the construction industry. And I would say the top two questions that immediately came up were: Is it going to increase construction costs and was this new approach fully vetted? Good for us, the answers to both of those questions, we already had the answers and they were good answers; that is, construction costs, not only they don't increase, they’re actually lower.
And so that’s a big attractive feature of this measure to builders in particular and regulators that are sensitive to passing anything in California that will increase the cost of construction. And then the second question of was this approach fully vetted? Yes, it’s already part of the model code so that puts people at ease immediately. And then we’ve done a lot of work to gather data and crunch that data to validate this Water Demand Calculator, comparing what the design using Water Demand Calculator would be to actual water use in multifamily buildings. And that comparison was very favorable for the Water Demand Calculator.
Christoph Lohr: I think you’re touching there, Steffi, on a report, or maybe a series of reports or infographics, that was put onto localenergycodes.com, which I think is specifically for California.
Can you touch on a little bit about those reports just for our listeners, and then for our listeners we’ll put the link in the show notes here. But can you just touch a little bit about the report that you all compiled?
Steffi Becking: Yes, this report was actually what constituted a bulk of that petition that was submitted to the regulators to have this Water Demand Calculator measure considered. And basically we wanted to validate the Water Demand Calculator using actual data. We were very lucky to get a number of groups to share data with us that they’ve collected for some other projects, energy efficiency projects. It mostly was peak water, flow rate water data for hot branch, but it was still useful. We took that data that was collected by other organizations and like I said, we’ve compared it to the design values for hot branch that one would get using the Water Demand Calculator. And we basically found that the Water Demand Calculator is more accurate, but also a conservative method to design to design a plumbing system.
So that’s what’s in the report and it goes into great detail about the kind of buildings we’ve looked at and who gave us the data. So big thanks to those faults and all the insights that we were able to get out of it.
Christoph Lohr: I was going to say, I want to go back, Kelly, to one of the things that you mentioned right at the get-go, which was that water and energy are linked, and I think the terminology is the water-energy nexus.
Can you touch on a little bit about the benefits of the Water Demand Calculator from that water-energy nexus standpoint?
Kelly Cunningham: Yeah. Well, at the very basic level, it takes energy to move water around the building, takes energy to move water to the building as well. And the other part of my work, the majority of it working in energy code, we also have all the systems tied to heating water, especially for multifamily and single-family, with the advent of the decarbonization movement, is switching to new technologies and configurations as well because of the coming heat pump revolution. So we have this entire ecosystem of how water is delivered in residential properties and we have to look at every aspect of that.
How much energy is it using to get people the water they need? So we look at both at, OK, Appendix M and what savings are potential for having the reduced pipe size, the right-sized pipe size I should say, but then we also look at the larger ecosystem and say, what are the machines feeding into that system doing, and can we reduce their energy use, especially as we're relearning some of these systems with central heat pump water heaters in particular, which the design decisions on making those functional and efficient systems are still evolving. That went maybe from macro to micro, but we do look at that entire ecosystem and we will use the Appendix M work to inform, well we did use it for the 2025 code cycle, which is the actual rulemaking at the California Energy Commission is just starting, to inform a multifamily report and we’re going to use it again next cycle for 2028 to see if we can make even more energy benefits derive from this work.
Christoph Lohr: Excellent, Kelly. And kind of in that same vein on the water-energy nexus and asking the same question to you, Steffi: Was there, you mentioned some of the reports. We touched on that one from the local energy codes that you worked on.
But was there any other sort of qualifiers in terms of water-energy nexus or construction costs that were beneficial in terms of validating or overcoming some of the objections, Steffi?
Steffi Becking: Yeah, as far as I know, there are actually five different teams that worked on quantifying the benefits, and all those five teams published reports in the past four years.
So there is a range of literature out there now that they actually went ahead and analyzed the impacts, and there is a range in the estimated impact due to variation and methodology and considered building prototypes. What we found on the construction cost side, Gary Klein evaluated one building. It was a 92-unit multifamily building in Seattle, Washington.
And for that one building, we’ve estimated that the upfront construction costs would be about $600 to $1,200 per dwelling unit. So for the whole building, you multiply that number by however many units you have in the building. Again for builders, that's very nice. So instead of telling builders, hey, you need to spend a little money upfront to get some benefits down the road, and it’s probably going to be occupants and landlords who are getting the benefits.
Here we have the opposite story of you, the builders, you get the benefit. Hooray!
Kelly Cunningham: Yeah, and for the for the dwelling occupant later we did have an estimate for a single-family dwelling that that will be somewhere over 1,000 gallons per year that could potentially be saved. We also have an estimate of 5.3 kilowatt hours per dwelling unit per year on embedded electricity savings. And if natural gas is used in the home, then 7.7 therms per dwelling unit per year.
We have a chart in our executive summary. If your listeners only have time to just read something short, we also have a fact sheet, so even if they have less time in the executive summary we’ve got a table there that offers soe of this water-energy nexus estimate for them to enjoy.
Christoph Lohr: Yeah, it sounds like, I know IAPMO, we have a couple studies out on our web page, the Stantec report, which talked about construction cost savings, and then the Arup report, which tried to qualify, like you mentioned, Steffi, in terms of prototype the water-energy savings and sounds like the numbers you all are seeing in terms of some of the potential out there, let’s say, in terms of construction cost savings, water and energy, that we’re kind of talking in the same ballpark in terms of some of the opportunity out there from right-sizing with the Water Demand Calculator. Is that fair?
Steffi Becking: Yeah. And it basically will depend on the type of building that you’re looking at. But yes, I think everybody’s coming up with numbers that are in the right ballpark.
Christoph Lohr: Excellent. Well, what would you tell your colleagues in other states that are looking to adopt the Water Demand Calculator about what you learned about this process?
Steffi Becking: I would say two things. One, stakeholder engagement is key, absolute key.
And not only it’s important to get this adopted, but at the end of the day, OK, now it’s in the code, and it happens to be in the California Plumbing Code, but it’s an opt-in option. So we still need people to know it’s there to know it’s an option and to apply it to the actual construction projects and plumbing designs. So that stakeholder engagement starts early on when you’re trying to put it into the code, but it’s got to continue on to actually see the difference on the ground. That's the first point I'd make, and the second one is data, and validation with data; that was very important to get the plumbing and building industry comfortable with a change. Like you said, those industries are change averse, and that’s fine. But data is what I think really helps people to get comfortable with change.
Christoph Lohr: Excellent. Kelly, anything you want to add?
Kelly Cunningham: Well, if listeners are collecting data about water use and multifamily buildings in particular, but also single-family homes, and if they apply this Water Demand Calculator and have buildings monitored with this in practice, it would be great if the community could share their experiences, because we’re going to build on this; maybe in the future this will be, as I said before, normalized — the standard, the first choice. But in order to get everyone comfortable with that, sharing what we learn as a community concerned about these issues, I think is really important. So maybe we’ll reach out to our team and say let’s combine forces or can I learn more? And I welcome that.
Christoph Lohr: Excellent. Well, to wrap things up, one last question. What I’d like to ask is, frankly, I love learning from both of you and then you all sharing your expertise and insights with me. The next time we have you on the podcast and we’re talking about Water Demand Calculator — what do you think we’re going to be talking about in terms of Water Demand Calculator adoption?
Steffi Becking: I hope we’re going to be talking about right-sizing water heaters.
Christoph Lohr: OK. Excellent. Kelly?
Kelly Cunningham: I love that answer. I’m hoping we’ll be talking about how this is being embraced and it will be embraced maybe as the top option, maybe the mandatory option in some areas, and about all the data that we’ve collected to show that it works, but I love the right-sizing water heaters discussion as well. That’s a whole other intervention and maybe we’ll be on the show again to talk about the same questions on how good data helped to change hearts and minds and that expertise as well.
Christoph Lohr: Excellent. Well, on behalf of The Authority Podcast: Plumbing and Mechanical and IAPMO, I just want to say, Kelly, thank you so much. Steffi, thank you so much. I think our listeners are going to get a lot out of this recording and just want to say thank you for taking time out of your busy schedules to share with us and and to help us all learn.
Kelly Cunningham: Thank you for hosting.
Steffi Becking: Yeah, absolutely. This this been fun.
Christoph Lohr: Thanks for joining us on this week’s episode of The Authority Podcast: Plumbing and Mechanical. Love this episode of the podcast. Head over to iTunes to subscribe, rate and leave a review. Please follow us on Twitter @AuthorityPM, on Instagram at The Authority Podcast or email us at iapmo@iapmo.org. Join us next time for another episode of the Authority Podcast: Plumbing and Mechanical.
In the meantime, let’s work together to make our buildings more resilient and shape us for the better.
