Kelly:                                  00:06                   welcome to buildings and beyond

Robb:                                00:09                   the podcast that explores how we can create a more sustainable built environment

Kelly:                                  00:13                   by focusing on efficiency, accessibility and health.

Robb:                                00:18                   I’m Robb Aldrich

Kelly:                                  00:19                   and I’m Kelly Westby.

Robb:                                00:22                   This episode I’m talking with Lois arena, who is an engineer and the Director of passive house services at Steven Winter Associates. And she’s in charge of, well, all things passive house at this company as you might tell from her title, but she’s really been involved in some of the really the biggest passive house projects the United states to date. And this conversation is really a big picture. It’s a little different. I asked her- we should do it passive house episode and she said, you know what, I have a list of FAQs that I answer 4,000 times a week. Let’s talk about those. So it’s very easy on my part. I just asked her FAQs, but here’s a primer on passive house with Lois.

Robb:                                01:07                   Thanks Lois. Thanks for being here. So this is a little different. Lois is really the passive house maven here at the Steven Winter Associates, she might use stronger in terms- “in charge of passive house” I believe I’ve read quite recently. But this session or this podcast is going to be a little different when we sat down, it’s like “what would make a good passive house podcast and you said “here’s the top 10 FAQs that I get about passive house 400 times a month.” And you actually have a little brochure that you had printed up, which I didn’t know about. So I was happy to read that and see that. So here we go. This is, this is the top several I picked and choosed and maybe I added on a two of my own. So first, what is passive house?

Lois:                                   02:04                   Passive House is a building energy standard and it currently is the most stringent standard in the world. And it’s a performance based standard that gives you what I call an energy budget. So there’s an energy demand per square foot that you’re not allowed to exceed. And there’s one for heating, one for cooling, and then one for the whole building. All energy uses in the building.

Robb:                                02:29                   So is it energy consumption? Are there peak demand requirements also? This is like an energy consumption over the course of a year?

Lois:                                   02:36                   It’s an annual energy demand growth. Yes. For all three categories.

Robb:                                02:41                   And that’s, that’s at its core. That’s what it is at its core.

Lois:                                   02:45                   Yes.

Robb:                                02:48                   So key requirements, other than the energy demand?

Lois:                                   02:51                   There are some key requirements. So they’re not just concerned with energy efficiency. They want to make sure the buildings are durable. So no moisture problems, no mold, no indoor air quality problems. And they also want to make sure that they’re comfortable. So they don’t want you to squeeze down the energy efficiency by say, a massive PV array to have a really poor envelope. So they focus on the envelope of the building first, they focused on comfort, durability, and then energy efficiency.

Robb:                                03:17                   Okay. Interesting. So envelope is the first target?

Lois:                                   03:22                   Envelope is first.

Robb:                                03:23                   Okay. And air tightness is a big, big piece of that. I think?

Lois:                                   03:27                   it’s a very big piece of that. Yeah. The passive house air tightness requirements, depending on what code or standard you’re comparing it to, is generally five to 10 times tighter than any other standard out there or code requirement. Yeah.

Robb:                                03:39                   Yeah. I remember 20 years ago before I was here, I was doing solar thermal systems, hydronic heating systems and somebody told me they did blower door test on their house and came back with one ACH 50 and I told him he was full of crap. There’s no way a house can be that tight. I was like obviously we can’t trust this guy at all. He’s smoking something. But that’s like, you know, until recently, I think it was like 0.6 ACH 50-air changes per hour, at 50 pascals. I thought they were shifting to an area or a or a per square foot of enclosure?

Lois:                                   04:22                   They are. Well, there’s two different standards. Ones the U.S. Standard and one’s the international standard, the US split off from the international standard. When they did that, they went to solely a cfm per square foot of facade. And that’s for large buildings for the US. That’s 0.08 CFM per square foot of facade. So very, very tight. The international version, they were used to doing smaller buildings. .6 was their standard. As the building’s got bigger, they came up with a recommendation for buildings over, I think it’s probably 10,000 square feet actually. So not even that huge that they recommend that you go to 0.033 cfm per square foot of facade. And so for a building like Cornell, that’s almost, I think 200,000 square feet.

Robb:                                05:12                   This is a dormitory for Cornell medical school?

Lois:                                   05:15                   This was the Cornell tech campuses student housing. So not really a dorm. It’s their tech campus in New York City on Governors Island. And so that air change rate actually equates to about 0.15 air changes per hour for building of that size. When you go down to 0.033.

Robb:                                05:40                   Okay. So you blew it away on that project. Other key requirements. Balanced ventilation. That was on your list of FAQs, and continuous insulation. Those three I think where the, ‘you got to get those right or you’re hopeless” right?

Lois:                                   05:58                   Exactly. So the continuous insulation for durability, the air leakage actually was also for durability. When they first started the program over 25 years ago, they didn’t have that type of requirement and they wound up with homes that had mold and mildew on the walls. They had some massive failures and so they reevaluate it because air could get in, but then they couldn’t dry out because the heat flow through the walls was so low. So they determined from testing and analysis that they needed to go down to 0.06 for durability reasons. It wasn’t just for energy efficiency. So that’s where that developed from. And then the mechanical ventilation, obviously if you’re that tight, you got to provide some fresh air to people and it has to be balanced. Exhaust only systems won’t work. And it stresses the fans, right? You start whining, you using up more energy than you typically would if you’re depressurizing the building all the time.

Robb:                                07:02                   The fans will burn out the motors will burnout. So, what can be certified? This is also on your list.

Lois:                                   07:09                   This is a common question. Yes. What can be certified, right? Yeah, actually anything can be certified that either has a heating or cooling system in it and that you can do a blower door test on. And so for example, something that we couldn’t certify, which was really interesting and sad because I wanted to do this project was, one of our developers asked us if we wanted to work on a project in Hawaii.

Robb:                                07:35                   And you said..

Lois:                                   07:36                   Of course, and that product is mine. I’ll be the lead consultant on that one. And I will open a Hawaiian office if I need to.

Lois:                                   07:44                   But it didn’t need cooling because of all of the ventilation there and the ventilation system is a passive ventilation system. We just open grills in the walls. So it made me want to move there, but we could not certify the project

Robb:                                08:00                   Yeah and that’s the question that’s on the list. But there are some climates where passive house is kind of moved, Hawaii being one, San Diego probably. So not only houses though, anything?

Lois:                                   08:16                   Anything. We’re doing office space. Somebody has a dentist’s office certified down in Virginia, so it’s high rise. It’s low rise. It’s offices as any type of building you’re doing. We’re doing a factory in Sri Lanka, so anywhere, any type of building

Robb:                                08:32                   Correct me if I’m wrong, but we’re doing like a portion of a high rise office building, a section of the offices within a really big building.

Lois:                                   08:44                   Exactly. So in Boston there’s a project going in Winthrop square that is 55 story tower, 35 stories of that are residential, about four stories on the base are retail, restaurant, that sort of stuff. And then there’s 20 stories in between those two spaces that is office and so passive House Institute has agreed to do it as a pilot project because they haven’t really done a section in the middle section of a building like that before.

Robb:                                09:12                   It started with single family homes, yes?

Lois:                                   09:15                   It started single family low rise. Yeah. Right.

Robb:                                09:18                   But evolved a lot from there. Okay. Next question on your FAQs, is what is the price premium for getting passive house?

Lois:                                   09:27                   That is usually number one. You can always tell the developer in the room, you know, you’re like, ah, so that’s a tricky question because it all depends on where your baseline is.

Lois:                                   09:37                   If you are a code minimum builder that does nothing more than code buildings, you have a lot farther to go, than if you are a typical leed silver builder and that’s your standard, you’re already doing stuff for energy efficiency, you’re already doing probably some good ventilation strategies. It may not be passive house level, but you’ve already got some good stuff in there. And you’ve already got better insulation levels, and to get to leed silver, you’ll need some good energy points. So it depends on where you start from. And it also depends on if you come with a building plan already set and say to me, “make this passive house” instead of a program and say, “look, I need a hundred units. It can’t be taller than this. I need some retail space,” and the designer is left with your budget to create a project that fits that budget.

Lois:                                   10:27                   So we have estimates anywhere from zero additional costs because of those types of projects, to 15% is usually the high end. And that’s usually the person that comes to me with a set of plans and says, “make this one passive house” and we don’t want to change anything. So, you know, ventilation is going to be an ad because you don’t have to do supply, right. Ventilation’s an add, your windows are probably going to be more expensive. So you know, you don’t always have to go to triple pane windows, but you’re always have to go to a much better window than is very typical in the United States.

Robb:                                11:03                   So you primarily work on larger multifamily buildings, office buildings, very tall buildings. Yes. Cornell Tech was 26 stories. It was the first tower that tall and that big in the world to get certified.

Lois:                                   11:25                   Yeah. And that sort of set the ground for all of these other people with large buildings coming and asking us to be certified.

Robb:                                11:36                   And all over the world. Oh my gosh. You’re going to Sri Lanka in two weeks?

Lois:                                   11:41                   Dylan’s going to do the final blower door tests around the Sri Lanka factory. I’m going to Vancouver in two weeks, cause they’re adopting it as their code. So they need people who have done large buildings to come out and train some of their developers. So they’ve hired myself and some other consultants who’ve had experience on big buildings and were going out to do some pretty intensive two, three day workshops for their developers

Robb:                                12:09                   Nice. All right. After price: O&M. Are there big changes in operation and maintenance with passive house buildings?

Lois:                                   12:16                   Generally, no. Generally you’re supposed to see lower maintenance costs because the building’s supposed to be more durable. You should see less rot, you should see less leakage. You should see, you know, less things that cause repair. The one area where you probably will have increased maintenance is in the ventilation system because the ERBs have filters that need to be replaced. So the extent of the extra maintenance depends on the type of ventilation strategy you choose. If you choose an individual ERB in every apartment versus centralized systems where you only have two or three, then you’ve got that many more filters to change if you’d go with the individual systems. So that’s where your increased maintenance would be.

Robb:                                12:56                   Makes Sense. And I mean, on the heating and cooling side, one would assume that the systems are smaller capacity, maybe lower costs, lower maintenance, that may not always follow.

Lois:                                   13:08                   That’s the hook that passive house uses to try and tell you that it’s a no cost option. Right? Like it’s a balance. You save money on your heating and cooling, but you pay a little more on your shell. But for large buildings, that’s not really the case. Large buildings, these high density buildings, all the large buildings are high density office space, everything is very high density. They generally have very high internal gains compared to a residential building. So the cooling system doesn’t decrease, the heating decreases almost to nothing. But the cooling stays there. So your demand, your whole annual demand, could possibly stay the same. Probably won’t go up because there are specific measures you do take to try and minimize the amount of cooling, especially from exterior. You try and use a lot of bypass for free cooling from the ventilation system. You do employ strategies to try and mitigate the internal gains, but you’re not likely going to cut it even by 25% the size of your system, so you basically have the same, if you’re using the same system for heating and cooling, you did not decrease the size of your system. So for small projects, yes, you’ll save money on your heating and cooling.

Robb:                                14:28                   I’ve worked on a lot of smaller projects and they can get away, even low rise multifamily, can get away with much simpler heating and cooling systems. Now this one surprised me, this one you said is the most common question that you get about passive house. Can occupants open their windows? Seriously. We’re talking about cost and Iq and ventilation, and this is like, you get this all the time.

Lois:                                   14:58                   All the time. People assume that because the building has to be so air tight, that the minute someone opens their window, it ruins the entire project. Its like “so well, you shouldn’t be able to open your windows. You can have operable windows” and we get in the biggest fights over this. This is like one of the silly things that’s so not true, but somehow has, you know, made its way through the little rumor mill about passive house and it’s absolutely not true. You are required in livable spaces, especially residences to provide operable windows. You have to, they want the occupants open the windows, to control their climate. They want the occupants to control their climate.

Robb:                                15:42                   All right. Speaking of speaking of windows, is there a restriction on the amount of glazing you can have in a passive house?

Lois:                                   15:49                   Technically no. There’s no written “You cannot have greater than 30% window wall ratio”. What happens is, the more glass you have, the better the window and the better the shell has to become, right. Cause the window is usually the worst portion of your thermal envelope. So when you go to some of these taller buildings, especially the market rate ones where they want to have floor to ceiling glass, they pay the price for them.

Robb:                                16:17                   I’ve been to Vancouver once and Oh my God, everything is glass.

Lois:                                   16:21                   Everything is glass, yeah. That’s what they’re fighting against right now. Yeah. That’s one of the big issues. So you wouldn’t, you probably couldn’t, in this climate, have an all glass building. You probably could in San Diego.

Robb:                                16:34                   Gotcha. Yeah. Very climate dependent. It’s all about the energy budget. What are the major roadblocks to passive house compliance?

Lois:                                   16:45                   So again, it’s pretty climate specific because we have such an extreme climate here that especially for ventilation, in New England, in cold climates in general, you need energy recovery or heat recovery ventilation. We’re very limited on efficient systems, whether they’re individual or central systems. We only have one or two options for each

Robb:                                17:11                   That are certified or that workout in the modeling?

Lois:                                   17:15                   That work out in the modeling and that have the type of controls and efficiency levels that you want, because you can’t, especially for individual ones, if the less efficient the ERV, the colder the air coming in, the more comfort problems you’re going to have with your occupants. So it’s really a huge concern. UL listing on these equipment, you need to make sure that they’re UL listed. We have very few that are. There’s a ton of great ERVs out there in the world. We just don’t have them in the United States. Canada has more options than we do. Yeah. And then the other part that we’re still seeing road blocks on, are small enough heating and cooling systems. I do hear that one heat pump manufacturer just came out with a 4,000 BTU head. We just got the notification today that that was released from the manufacturer.

Robb:                                18:10                   Oh so the one I saw was at a show. It wasn’t actually launched.

Lois:                                   18:15                   It wasn’t lost yet. We’ve got the official.

Robb:                                18:16                   Ah so I was misled. I’ll be making some calls.

Lois:                                   18:22                   They probably had all of their certifications by then, but I don’t think they had announced it to the public officially. So we just get the mass email. So that’s great news, but we need more. That’s one manufacturer.

Robb:                                18:37                   Yeah, absolutely. I agree. I mean that’s any building type. I mean you’re making the load smaller and smaller. And the way to heat and cool hasn’t changed enough, hasn’t caught up. What changes to standard practices will be needed to meet passive house criteria? The ceiling is the first thing that comes to mind.

Lois:                                   19:04                   Yeah. We’re constantly in meetings and people are like, “that’s not how we typically do things.” So there’s a lot more attention to a really good durable, flexible tapes instead of just relying on clock. That sort of thing. Everybody on the job has to know what you’re trying to achieve. That’s one of the things you can’t just have your electrician come in and repulser your installation around wire and you know, holster the building assembly and then leave and not have at least somebody else on site.

Robb:                                19:40                   Don’t make fun of electricians. Plumbers do it too, contractors, carpenters.

New Speaker:                  19:47                   Everybody does it. Every trade needs to be on board. The other thing you need to do is, and I always thought this was funny because I, since I’ve gotten into passive house over the last eight years, I’ve heard so many people talk about the integrated design process and then I’d go to presentations and they’re like, you need to have these people on board early. And I’m like, well, isn’t that how everybody always works? That’s how every passive house project works. I mean, you’re not going to get there if you don’t. You got to have a contractor ready so that they can help you with pricing and help bring down the cost. You got to have your HVC contractor on board because they need to know that the loads are going to be low, the building’s going to be tested, it’s going to be inspected and they have to believe you that the loads are going to be low so that they size the equipment properly. So really you need your whole team, all your consultants on board at the beginning. So that’s, that’s another pretty big change to standard practice.

Robb:                                20:34                   That makes sense. Absolutely. What are the implications to the construction schedule?

Lois:                                   20:49                   We get that question a lot. Coming from the northeast and in particular working in New York, the answer to that has to be, there’s absolutely no implications because they would never allow passive house in the borders of New York. If you told a construction team that you are going to delay their schedule by 10 weeks, 20 you know, whatever. I’ve had some of the consultants from Canada tell me that they tell the design team that they need to put the building process on hold between dd and cds for like, I don’t know, two months or so, so that they can go through the precertification process. And I go, no, no, we do not do that. We never say that. We are on board with the certifiers from the beginning. We’re constantly doing the analysis from the beginning and they looked at me like, well, what happens if there’s a big change again? Then we deal with it. But you can’t, you can’t slow construction team down by even two weeks. They would kill you. For half a day! You come in and you tell them there’s something wrong that they need to fix and, and it’s like, we’re going to do it now. Stay here. You’re going to sign off on it before you leave, you’re not leaving the site. There’s the occasion where a contractor changed what they were supposed to do in the field without asking, then they have to fix it. And so that has implications. But that’s not because it’s passive house. That’s because they didn’t do what was on the plans and their drawings and they didn’t come up with an acceptable solution and they did something wrong. So we have a couple of projects out there right now where one of the contractors did what they normally do instead of what was in their drawings. They just flew by the seat of their pants and now we have to go back and rip out some dry wall.

Robb:                                22:50                   Oh, this is probably my favorite. Are there conflicts between passive house and code requirements or other program requirements?

Lois:                                   22:58                   Yes, there are. And it all starts with Ashrae 62.2. Now mind you, I am on the subcommittee for that standard, but I am a conscientious objector to many of the things that they require. Alot of it has to do with the kitchen, kitchen ventilation and the studies that some of the labs had been doing and the high levels of ventilation that they’re requiring, and it’s exhaust only systems that are the issue. They’re requiring certain high levels of kitchen exhaust and I keep trying to tell them, you’re not going to get any exhaust because these buildings are too tight. And even if you’ve only built the building to LEED, an apartment in the middle of an apartment building only has one exterior wall. Only a few CFM is going to come through that, the 100 CFM that they’re requiring for intermittent or the five air changes per hour for continuous is not going to come through the exterior envelope. It’s not going to be fresh air coming from the outside. It’s going to be from the neighboring apartments and that’s anti what they want. But that’s what’s going to happen. And we can’t convince that a passive house would like lower levels of ventilation but balanced and supply to all the living spaces and then exhaust from the kitchens and the bath. But it’s much lower than the codes and the ashrae standards in particular require. So there’s a conflict there. They don’t see our low levels of balanced ventilation as better than their high levels of exhaust-only, even though I think we’ve shown on multiple projects that high level doesn’t work when you don’t have to makeup air.

Robb:                                24:39                   And it’s different. It’s different for single family detached than Multifamily. Not that exhaust only is always okay in single family, but you know the exhaust is not coming from your neighbor. It’s not coming from the garbage chute. It’s coming from outside. If it was coming from a crawl space filled with radon, that’s bad. That’s a concern. But yeah, I mean exhaust only in big multifamily buildings, nobody knows where that air is coming from.

Lois:                                   25:07                   Right. What we think is that, filtration is going to become a bigger part of the solution, but we don’t have that many great products out there yet that the lab’s feel comfortable would do a great job. And then again, it’s all based on maintenance. Right. All of these solutions are based on maintenance. Are you going to clean your filters? Because when you stop cleaning your filters, they don’t work either. So it’s one of the hardest ones to deal with. And most of the conflicts we have are with ventilation. It’s not really with anything else. You can talk about thermal breaks and the conflicts might be with your structural engineer, but there’s always ways to deal with it. The ventilation thing is one of those ones where there’s this constant battle. There’s line in the sand. Nobody’s really, nobody’s pleased.

Robb:                                25:50                   Yeah. It’s tricky. I don’t have an answer. I mean, I understand passive house. I mean they seem low to me, the pessimist requirements, but at the same time, yeah. Exhaust only in multifamily just doesn’t work. They know that.

Lois:                                   26:03                   And how do you ventilate a 400 square foot studio apartment at five air changes per hour, and meet any kind of energy budget? You know what I mean? It’s just ludicrous.

Robb:                                26:13                   Well here’s a practical question. Can the capacity of a ventilation system be higher but not always run? So do the modeling for a lower capacity ventilation and if somebody wants more they can boost it.

Lois:                                   26:27                   So very easy to do with individual ERVs. Yeah, much harder to do with central systems in large projects, but it can be done. I have spoken with people in the north, the northwest, that have been working on passive house projects and they put like things like inline booster fans in their bathrooms and so, and they have a variable speed drive on the central system that is supposedly responding to me boosting my bathroom. It takes a lot of controls and a lot more product, you know, a lot more pieces of equipment and people are weary of that. They would prefer to put in constant volume. Let’s balance that and get that to work and, but I think that that might be the next breakthrough. If we can do that effectively. Cost effectively. Practical. Yeah. I think it’s been shown that the boost when you’re cooking especially is important. Yup.

Robb:                                27:23                   Alright. We’ll solve that next week. Next time. Yeah. So those are all of your FAQs, which are good. Thanks. But I have two more questions and they’re not hard questions. Who is building passive houses and why? I mean the people that are doing it, who’s doing it and why.

Lois:                                   27:48                   So we have a lot of affordable housing developers going to passive house.

Robb:                                27:52                   Is that just our clients or are you seeing that nationwide?

Lois:                                   27:57                   Nationwide. We’re seeing a affordable housing agencies put it on tax credit applications. We’re seeing developers just come to us and it’s not necessarily because they’re getting incentives to do it. They see it as they’re owning the buildings, too. Right. So you have to understand that. So they’re paying part of the cost. So they see it as energy reduction. They’re also paying part of the heating for their tenants. So that is an awesome other energy reduction for them. But they are really committed to the people that live in their buildings. Yeah. and providing a low income, tenant with low energy bills, is really important to them. And comfort and durability and good indoor air quality. They’re just a wonderful Group of developers to work with.

Robb:                                28:37                   Yeah. In the 20 years that I’ve been doing it, it’s, it’s kind of mission driven groups that are really not just looking at the bottom line but really want to provide quality housing, quality buildings. It’s very gratifying to work with folks like that.

Lois:                                   28:52                   And then we have mission driven market rate people that believe in it. They bought into the 50 by 80 or 80 by 50 challenges. Right. Like they want to reduce carbon. They live in cities, that’s their goal and they want to be part of that solution and they’re willing to be leaders in that. So we have a number of market rate clients that are pushing that as well. Yeah. Trying to differentiate themselves.

Robb:                                29:20                   So not incentive driven. Awesome. That is cool. And geography, I mean, we’re mostly in the northeast probably, but I mean nationwide. Do you have a feel for other hotspots? California? I mean, big cities?

Lois:                                   29:35                   The Northwest. Yep. They’re a little more active there. Canada’s going crazy right now because of the codes. New York really is the driver, the city, the state, everybody’s behind this carbon reduction goal. Passive House is seen as one of the ways through, not the only way, but one of the ways through plus the whole push to net zero from everyone, everywhere, is passive house is seen as sort of like the first stepping stone, like getting your building energy use down by those metrics first. And then adding renewables and whatever other technology. And so it’s not necessarily the certification that is so important, it’s the just the measures, the principals. Yeah.

Robb:                                30:18                   cool. Last question. If we talk again in five years, what are we going to be talking about?

Lois:                                   30:26                   How stupid we were that we didn’t know this wasn’t actually going to work this particular way. Like for instance, you know, we thought, okay, it’s supposed to reduce energy use by this much and maybe to tenants are so comfortable they’re turning up their heat and want to be, you know, it’s that whole thing

Robb:                                30:48                   Or the modeling might not be quite as accurate as one might hope.

Lois:                                   30:52                   How often does that happen? Never happens. Come on. Modelers are fantastic. What we’re really hoping for right now is that all of our projects are going to employ some sort of monitoring. Because we are expecting some of these buildings to not perform the way that we hope they will. But if we can’t tell people why, then we’ve failed. Yeah, right. We just need to be able say, okay, here’s the problem. We need to look at this differently and move forward.

Robb:                                31:26                   A lot of the technology, like the heat pumps, the new ventilation systems, they’re just lot of new stuff being installed in building for five years being maintained to different levels of rigor.

Lois:                                   31:42                   One of the biggest issues is the maintenance staff education levels with this new technology as well? Yeah. Like they’re used to maintaining. We are working with the school construction authority in New York to evaluate what it means to go to this level of efficiency. Not Necessarily certifying to passive house, but these levels of efficiency, and they constantly talk about education of their current maintenance staff and what their maintenance staff will use. Even the schedules that are in the building management systems for turning things on and off. They’ll override them quite a few times because they don’t want to be dealing with turning them on and off for special groups. So they’ll just put them on 24/7. So you go look at the utility bills and you’re like, this is not what we designed. Yeah, so a lot of education is needed.

Robb:                                32:33                   Yeah. Hopefully these will be under a little bit of a microscope to inspect them, so yeah, we’ll figure all that stuff out. Cool. Anything else? Any other big picture passive house pieces. We covered a lot. We’re all experts. Sweet. Thanks Lois.

Speaker 4:                        32:59                   Thank you for listening to buildings and beyond. For more information about the topics discussed today, visit www.swinter.com/podcast and check out the episode show notes. Buildings at beyond is brought to you by Steven Winter Associates. We provide energy, green building and accessibility consulting services to improve the built environment. Our professionals have led the way since 1972 and the development of best practices to achieve high performance buildings. I production team for today’s episode includes Dylan Martello, Alex Mirabile, Lee and myself. Heather Breslin, thank you for listening and we’ll see you next week.