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Exterior Insulation Retrofit—13 Years LATER

A 100-year old Sears Roebuck house is a 21st Century example of net zero retrofit details and techniques
September 28, 2023

Well, thank thank you, Joe. And actually, I've got a few people just to think because the work I'm going to show you was done with the team. I had a lot of help I got. And this is my community and my tribe. So I want to tell you what I did with what I've learned from you. And, uh, Joe, who is my husband, my mentor in building science, Peter Baker and Kohta Ueno, who are the new owners of Building Science Corporation.

And in getting my presentation together, Kat Klingenberg gave me a great amount of inspiration. Lisa White and Skyler Swinford last night were helping me kind of put some things together. And there are so many of you I want to thank, but I'm not going to have time. Thank you all. So, I have a daughter who has developmental disabilities.

She was born with the cord wrapped around her neck, and so she's had some disabilities. How do you make a house following Stephanie there, that is, for the rest of her life, that's not going to impact her health and help her live more successfully and also just not worry about the government taking care of you.

A house that helps people be self-sufficient

How can you take care of yourself, and how can you make a house that you can take care of yourself so that it's not going to be a big burden for you? That was really my inspiration. So, I was looking for a house for her that was near a transit. This is in West Concord. There's a train stop there. She's never going to drive, but she needs to walk around and get what she needs, and that's that kind of town.

It was a kit home from Sears Roebuck, and 1906 was when it came to West Concord on, not Walden Pond, but the other pond across it, Warner Pond. I think we started this renovation in 2006. By 2009, the majority of the renovation was done. I wrote a story about it, and I think in 2005 or 6 maybe, I gave a presentation about what I was hoping and expecting to happen in this house.

But now I wanted to look at it and see, well, after all these years, how did it really perform? One of the things that I think is the theme about whether it's new construction or a retrofit is, for me, it was the inconspicuous conservation. This was a house that looked normal, it fit in the community, and we were doing crazy things to it.

In fact, during the renovations, my neighbor came and said, wow, who is funding that? And, or, you know, that retrofit is, is there the mafia or somebody, where are you getting on? I wanted it to be resilient. I wanted it to be something that wouldn't fall apart or that would last for her. So, and after we got in, we spent a lot of time commissioning and evaluating.

A 13-year-old retrofit brings net zero lessons into focus

That wasn't just a 15-minute thing, or a one-day thing, or a one-month thing, or a one-year thing. Looked at it, we're looking at how it's performing, what the indoor air quality is like, is she warm, is she comfortable, are they going to be able to live there successfully. And we did some returning to problem areas.

One of my big heroes and fans is Dave Joyce, our master carpenter. I don't know, Dave, where are you? He's here somewhere. Whoa! There he is. He never said, "That's stupid, don't do that." He said, "Okay, let's try it." And he helped me find the problems and fix them, and that was really neat. Then, you know, we have new technology happening during these 13 years.

So, how did I adapt that into this house? We did. For instance, when we first built the house, we didn't use an HRV; we were just using a return to the air handler with outside air. So, we had these continual improvements over time. I will say that the cost of this in the three years as we were renovating it was about a hundred dollars a square foot. It had all new systems, which it needed after 1906. That included new heating, new electrical, new plumbing, and all this stuff you're gonna see now.

This is just a slide about why it's important to go back and look at what you did. You know, there are so many houses. Everybody has a house. It doesn't matter what we talk about. At the end of the day, all of you are gonna say, "Can you help me with my house? I need my house to be a place where I can live comfortably." That's important. Everyone here who's cognizant about living in their house knows they need to do that.

Then, you can talk about the lessons you learned and what you should do, and then goals change. So, the goals when I first started this house were one thing. I was trying to make it as close to zero energy as we could. But there were things that changed along the way, which made me make different decisions about what to do.

Goals: Better energy conservation, comfort, and IAQ

The goals were basically performance-driven: improving comfort, indoor air quality, more efficient use of space, a big thing. Many people are just building additions to houses when you can really find some space within that structure and use it. Of course, improving long-term durability was part of it, reducing operating costs, and increasing energy efficiency. This was when the term "deep energy retrofits" kind of got coined. Some thought it was an ironic statement. But the point was, they were really trying to touch every part of the house, including the six sides of the cube, and improve its airtightness and all of those things.

And it also was about really securing the building's future. It was a good member of the neighborhood. It fit in well. And again, it was inconspicuous. So these were the enclosure goals. We were looking to achieve air tightness between 1 and 2 ACH 50. At the time, the best windows I could get were replacement windows, about R2. Then we tackled the slab, basement, walls, and roof. It was very poetic. 10, 20, 40, 60. You know, Windows 2. Air tightness 1. Woo! So, that's kind of easy to remember. And it almost works in every climate zone. You can do that. You can do it fairly easily.

So, we were making it easy to understand. Okay, now I have a chart and graph and all of that, but here's what these charts and graphs show. We wanted to achieve a 72 percent reduction, at least that was the plan and that's where we thought we were going to be from the original condition of the house. It was an old house, it hadn't been renovated since 1906, metal siding, all knob and tube, an old oil tank and an oil furnace, boilers, excuse me. Then we expected to get a 44 percent reduction in total energy use compared to the national average. And then as we had a plan to put on photovoltaics, we aimed to provide a 76 percent reduction in total energy use with respect to the national average.

So, that's really where we were headed with this. And this is the house after the renovation. It doesn't look a lot different than before the renovations, except for it has beautiful colors and no shutters and not vinyl siding. And I like it, so. What we were really doing was adapting the perfect enclosure for retrofits.

Insulate all six sides of the house

This is the six sides of the cube. We're touching every one of those sides to try to improve, we're blanketing the whole house to make it more comfortable, more predictable, and better to use. Hopefully, we can control the indoor air quality because we know where the holes are. We're not going to be bringing in bad stuff that we don't know about. And we're going to be able to provide air where we need it, clean air where we need it, or at least, outside air where we need it, and filtered as well.

This is way too small to read, but the enclosure upgrades are listed here. I'm not going to go through them necessarily, because what I really want to talk about is how we're blanketing this house on the six sides of the cube. But there were a lot of things that got upgraded, and I mentioned them, from the slab insulation, the above-grade walls, the siding. We created a cathedral ceiling in the attic so that we could take a 2,000 square foot house and add some more living space, another bedroom and bathroom up there. We needed to get rid of the old sag wall that was between the second floor and the third, the attic space.

We did that. We replaced basement windows that were single pane, and we replaced above-grade windows that were single pane, double-hung with a storm that didn't fit, and you couldn't open the windows, which I hate. So, and we tried to replace some of the exterior doors, but we left most of that in place.

Okay, at this point I'm doing a little interjection. This is a new build, because we said we were doing old and new construction, right? This is a new build, it's a Habitat for Humanity house that we designed. You can download these floor plans from our website; it has all the details in it. But here's my point here.

It's not that hard to put insulating sheathing on the outside of your building. You know, this is a women's build; they never did it before in their life. We said, "Okay, here's your ruler, two foot on center, you know, put the nail in, I know you can find it," and there they're doing it. So no whining about that.

And there was the finished product and it's in Westford. It's down the street from where we live and they're incredibly happy there. And I'm incredibly happy that they're happy. I also want to say that even when you have to work with the government, this is the NIST Zero Energy Demonstration House. It's in Gaithersburg, Maryland.

You can also download those drawings from the NIST site and see what we did. But basically, every side of this cube has two 2-inch layers of foil-faced polyiso. We could use, now we would probably take something like a wood fiber insulation, but it wasn't available at the time. But there they are, you know, had to be publicly bid, we didn't know who we were getting.

We had to give them, you know, a little bit of training, whatever, but they did it. And you can follow the performance of this house online too, they've been monitoring it for years now, and testing a lot of things about how they work with a zero-energy house. And that was, that was the way that house looked in the future when it got completed.

Alright, so back to the other house, the mechanical systems. We took out the old boiler, we, and the oil tank, and we replaced it with an air handler in the basement, and now an air handler in the newly finished attic space, so there's a little bit of mechanical space there, a little bit of mechanical space in the basement.

Harvesting living space in the attic and basement

But we were able, 2,000 square feet, we were able to pick up another 600 square feet of living space in that attic, another 600 square feet of, you know, realtor-approved, like I can count that square footage if I needed to sell it, in the basement. Comfortable on every floor. And, let's see, so the air handler in the attic, we basically used ducts for distribution.

You can see with the arrows basically how that distribution happened. The upstairs air handler took care of the second floor in the attic. The downstairs air handler took care of the basement and the first floor. We had, obviously, we had bathroom fans in every bathroom, those needed to be added. And originally, in this diagram, you can see we were bringing outside air into the air handler to get our air exchange.

As we went on, a year or two later, we added an HRV in the attic. Because we had a way to provide that distribution, we were able to pick up air from the first floor and bathrooms, and then redistribute it into the hallway. Now, let's talk about the water continuity layer.

Again, another diagram, but it explains how it sheds water. So we went down to the board sheathing. In this photograph, you can see where we blew in cellulose to fill that 2x4 wall. It's an old house. There's a lot of framing factor in there. It's really hard to get cellulose to fill it well. We did some infrared to see where we didn't get and we went back to do it.

On the higher level, you can see we're using what I call the squiggly DuPont, which is their water-managed material. I think they made it for stucco, and it was a little bumpier than the flat stuff, so it gave us a bit of a drainage plane as we were coming back to put on the insulating sheathing after that. You can see that. We also basically rewrapped the windows. We took out the old windows, and I'll show you more pictures of that. But we didn't want to affect it on the interior. They were living in this space while we were doing the renovation. It had beautiful trim inside. I didn't want to mess with that. It had beautiful plaster inside. I love old plaster. It's fantastic. We didn't want to mess with that.

In the basement, we created the tub, EPS tub. You can see there's a drainage mat turned up. So, and then we have basically distribution underneath that slab that's coming. So if there was any water penetration, that would then go to the sump that was on the side. That was a way to kind of preserve that space.

Air sealing is tricky in the attic and the basement

In the attic, trying to make the air control layer, we used some tar paper to kind of cover the joint between where the exterior walls meet the roof rafters. If we were really gonna go crazy, and we didn't do that, we would have done a chainsaw and cut off those rafters and rebuilt them. We did that in our house in the barn in Westford, so Joe's got pictures of that, too. But we didn't think we needed to do it. It turned out that was probably one of the leakiest spots in the building when we came back.

This is the basement again, and we've now added a closed-cell spray foam to it. We're going to build a stud wall in front of it, and that will be the finished space below. Up in the attic, we also used blue spray foam, and we filled the rafters with that. So, the R60 roof is made up of the spray foam that's filling the rafters, plus the two 2-inch layers of foil-faced poly iso on top of the roof.

My neighbor came over and asked me if I was crazy and where was I getting the money to do this. Yeah. Oh my god, yeah, you wrapped the whole house in a Faraday cage, like, are you paranoid? What's, what's going on? But again, doing it today, there are a lot of materials that you can use. We probably would have used, you know, the wood fiber insulation to do that, and it would have worked very well.

In the basement, and I think what I'm trying to show here is how we transferred the thermal continuity at the rim joists between the basement and the first floor by spraying that foam in. It then is contiguous with the rigid foam on the exterior wall, so we're getting a sealed cube and I'm going to have control of that inside air.

Windows are a key aspect of efficient walls

Here's Dave putting in the replacement windows. We basically took the old windows out from the outside, again leaving that beautiful trim on the inside, and gave it a new flashing around the fins that were on these replacement windows.

Here's Dave finishing up the inside with caulking, and again, you can see that it really had this lovely stately sort of mid-century trim on it that I just did not want to mess with. But on the outside, because we were putting two 2-inch layers of foam, those windows were actually inset a little bit more than you might traditionally see. So is it an innie or is it an outie? Well, these are innies, okay? Innies, I think you need to take greater care to make them not look stupid. So, in this case, where there was the original sill, and then we, I think I have a picture, yeah, we basically added a piece to it so that that sill did not look like a thin paper sill. And there was some dimension to it. And there you have the innie windows. They look pretty good.

This is just a slide that shows kind of the layering that went on. Again, the stucco wrap from DuPont that was wavy and gave me a little bit of space. And then we, two 2-inch layers of this foil-faced foam. We religiously staggered the joints from one to the other, again, hoping to improve air tightness. We've got some furring strips on the walls at the corner so we can get the corner trim on so it doesn't look weird. Here they are doing it, and putting the stuff up, Dave's team, yay, making it work.

And here they are up at the attic, at the wall roof interface. So we're adding four inches of insulation to the outside face. We're also adding it to the roof deck. Well, that was going to make, if we didn't do something, it was going to make this really ugly fascia and soffit. So the geometry was just to move it out four inches. That way, you can make the soffit and the fascia look correct. This is what they're working on now.

PV works better on roofs that are not pyramids

In 2010, this was another beautiful thing. We decided, naively, that this house is perfectly north-south, east-west. I'm going to have a south-facing slope on the roof where I can put PVs. Then it was like, wait a minute. This is a pyramid. This is a triangle. I don't think that's going to work. Then we had dormers in the middle of it. So we said, okay, we're making a boat shed. Dave made this beautiful post and beam structure. It's my garden shed, or the boat shed. And we've got the 4.9 kW PV system. 28 of them, 175 panels. They've got micro inverters on them. The reason for that is it's pretty near a lot. It's about 50 feet. There are trees on either side. So even though that's directly south-facing, I get some shade in the morning and shade in the evening. My understanding when I was buying all these was that if we lost the whole string, we just weren't getting power on one of them. So this is a way to make sure that all your panels are reporting the energy that they're collecting, even if the one on the same parallel circuit wouldn't have been if you connected them all together.

Max? Oh, yeah, that's my dog Max. Yeah, my Sheltie. Yes, and he's no longer with us. But yes, he thankfully posed in front of him for me. Thank you. Alright, in actual performance, the same graph again. Here's what we had. Without the PVs, we had a 75 percent reduction with respect to its original energy use. With the PVs, we had a 60 percent reduction with respect to the national average. With the PVs, the house had an 80 percent reduction with respect to the national average. So, pretty darn good.

It has natural gas. We switched, we took out the oil-burning furnace and the oil tank. And it's got natural gas for its fuel right now. So, metrics. Total energy use is 62 million BTUs source. The national average was about 190 million BTUs source. So that was a pretty good reduction. The total conditioned square feet after the renovation was 3,600. So if you're doing the math there, that's, before PV, about 33.5 kBTUs per square foot. Afterward, with the PV, about 17.1 kilowatt BTUs. And, you know, air tightness matters.

When we first finished the house, it was about two. We went back and started to find the leaky areas. When I say we, that was Dave. Thank you very much again. And, replaced, you know, a leaky bulkhead door, front door, back kitchen doors. Tried, we should have also taken the porches off the front and the back. We didn't do that, so we had to kind of... meticulously take down this porch ceiling so we could get to the wall underneath and really air seal that. And then the HRV was installed, really eliminating the need for the central air handler and so that helped us with air tightness too. The outside air to the central air handler.

Superinsulation details worked as expected

So, okay, and here's the other thing, the super-insulated assemblies worked. We've gone back, and on the roof, we removed the chimney. It turned out it was wet, not really repointed well. It was really bringing water and humidity into the house. And so we took it out, we closed down that hole, and of course, air tightness improved with that as well. But we could see with that roof assembly how all that sandwich of the exterior roof was working and there was no damage in there relative to the way we layered everything. The same was true with windows. We replaced three windows that were in the bedrooms that they made it, so I couldn't furnish it, it really upset me.

So we made them horizontal windows over the bed, and then on those windows, we used an R5 window. And so we were looking in the wall there too, 13 years later. Again, no damage, everything was good. You can always walk in a house. Me, I can, and I can say, "Is there mold? I smell mold." Like, did you walk in the lobby here? I smell mold. So, I always know with the smell test, like, is everything okay? If it smelled weird in there, something was wrong. But we haven't had that.

You have to actually attach sump pumps to electricity

The basement, we actually had a hundred-year flood about, I don't know, five years ago. And everything would have worked fine if I had actually attached the sump pump to the electricity in the basement. Somehow we missed that. So we got about a foot of, uh, maybe not a foot, but six inches of water in the basement. Luckily, we had metal studs, we had closed-cell insulation on those walls, and it didn't really cause... and then gypsum board, which we just cut off the bottom of it, and it didn't really cause catastrophic failure, and we were able to fix it.

Okay, my electric company there, it's Concord Power and Light, it's a muni. So, recently, they started giving us the charts about how much energy you're using and how much you're collecting with your PV system. And this is a two-year thing. So, in over two years, we basically still paid for 450 kilowatt hours.

PV brings energy use to net zero, but electric companies keep the change

Because, basically, we're giving it back to the grid. We're paying... they're giving us maybe five cents a kilowatt hour. We're paying like 21 cents a kilowatt hour. So it wasn't a win-win situation as far as I was concerned. And then we had a microinverter failure. This was new technology. Some of them just went out. So over the 12 years we've replaced every one of them. These are in-phase microinverters. They were like the... I don't know, they were only ones on the market when we first got them. And we've replaced every one of those microinverters.

Luckily, this, that roof in the, um, boat shed was, um, it was easy to get up, pull off a, a panel, replace the thing, um, and, and so we ended up collecting only about 68 million watt hours, uh, over that 12 year period as opposed to 73 if everything had worked right and we, you know, we worked it with the weather and the sun as it was shining during that period. So, the first three years, the average production of those kilo... of those PV panels was about 5,600 kilowatt hours.

The average electrical use in the house was about 4,000 kilowatt hours. Hot water use was about 170 therms, and heat was about 400 therms. If, in fact, I had a way to store that energy, I probably could have paid for at least a third of the... um, hot water use, um, by being able to use it. So that was... there's the goal for the future. How do I... how do I capture that so I don't give it back? I mean, Concord is really trying really hard to make everybody go solar and, and all of those things. And so they're trying to make it easy for people to understand. But still, it's not a win-win situation. They don't give you what you... um, what you take.

The goals of the house have changed over time

Okay, so what kind of impacts did this whole process make? Well, in Massachusetts, we did a deep energy retrofit program with all the utilities, National Grid and others. NYSERDA in New York State started doing some pilot programs. We continued with our Building America project and the research, and we kind of reported this stuff with our Building America projects. And FIAS Revive was really one of our inspirations, and we're, I'm so happy that they're doing that, and they're really looking at, you know, improving all six sides of the cube, not just a little bit of caulk there, and a little bit of, a little bit of blown cellulose where you could get it. So the goals have changed for this house. Um, you know, obviously, all electric and positive energy. That's where we'd like to be. Um, we ended up changing out the gas range. My daughter was not really comfortable with gas anyway for the induction. That was a kind of a win thing. Um, considering actually getting heat pump, hot water heater to store... store that electricity in the day and then maybe be able to use it later.

Carbon reduction is the primary goal

And I think if I was gonna get to zero, I'm still gonna have to add about, I don't know, three kW of PVs, and I can do that by extending that roof. So yeah, and the goals changed. Electrify everything. Carbon reduction. We need to do that. So, okay, here's what Skyler helped me with last night.

If we had only done a light retrofit of the house, meaning blowing cellulose, caulking, and sealing all the joints, like weatherization really does, we would have ended up still needing a five-ton heat pump. We ended up with this DER and reducing the load. We've really been able to, our max is a two-ton heat pump when we finally get to that.

The blue represents the enclosure upgrades and how that was affecting carbon. And of course, we had a lot of poly and blown foam sheets in there. So that's that bright blue at the bottom of the retrofit, but it's really dwarfed when you look at the green, which is the heat pump refrigerant leakage over a 10-year period. Just the difference between 2 tons and 5 tons. That's a huge emission there, and so that was worth it. And then, the operational carbon, what difference does wrapping all 6 sides of the cube and making it airtight actually make. And so there was a big, big difference there. Thank you, Skyler, wherever you are.


I was just, it was a gut feeling to me. Okay, but there we have a modeled performance. He's got a great tool to do that. You should see Skyler if you want to do it. There he is.

Right, thank you, thank you. That's what I meant to say. So if we had used a fiber, a rigid fiber insulation on the outside, we would have no blue. You know, we could have used it up in the attic, too. We could have used it under the slab. Joe just did a book for timber HP that has all those details. We could have done the whole sixth side with it.

And that would have made a difference, too, so that would be something we might do. Not with this one, but with the next one.

Honey, didn't I tell you about that? All right. And, uh, Lisa's, okay, this is Lisa's, Lisa White's, slide, and it's just showing that if you don't do something to your building enclosure, you're still not shaving your peaks. You got your peaks at the wrong time. It's not working for you by doing the whole building enclosure, skipping down to the very last one on the left. Now you've shaved off your peaks and all of a sudden you can size equipment that's really gonna work and do what you need it to do. Was that about right Lisa? Okay. Thank you. All right. So that's the end.

Q&A Session on residential net zero

Thank you.

Dr. Bales. Okay. Okay. You said you put an HRV in. What does the wintertime relative humidity go down to and are you using a humidifier? It wasn't an issue at all. I haven't really measured it, but you would know what this is my feel. I my throat and Erica's throat and how she feels. So it didn't really it didn't get below 30%.

I'm, I'm pretty sure about that, but it wasn't measured. I have to admit. It's just I could feel it. You can feel dry. You can feel humid. Hi, Chris. Hi. I'm always inspired. Oh, man. You inspire me too. Um, so, I'm new to the carbon counting piece. So, I just wanted to understand what you were talking about. Were you saying that because you reduced from 5 tons to 3 tons, the avoided carbon of that was, um, Um, a better amount of carbon, or a more amount of carbon saving than the blue carbon of the That's right.

That, I think, thank you. That is the point. If you look at, if you looked at that chart and you looked at all the carbon that was used to make those materials that we did that retrofit with, it was dwarfed by the amount of carbon saved by reducing from a five ton to a two ton. And that leakage of. And then, uh, so that was, that was really the big point.

And it was dwarfed by the fact that the energy savings and the amount of energy used was so much less. I feel it was worth it. That's what I want to say. I think it was worth it. So, does that answer? Yeah. Yeah. Okay.

Alright, we got, we got Ken here. He helped me with all of this too. Let's let Ken, Ken will you start? Thank you for this and thank you for sharing it. I wanted to say that to my mind one of the most beautiful images you showed was when the house was stripped down to the board sheathing. Yeah. And it's, it's gorgeous because from that point there's so much potential, right?

From there we know that the hard stuff is done and you can get this to a really efficient enclosure. And I'm sure we all see as we drive around or, or live in the world, lots of buildings that get to that point, but they don't go the direction that you took or, or that I took because I followed your lead.

Han, what are your thoughts on how we can capture that potential and redirect, even if it's just a small portion of those residing jobs to go towards deeper? Well, you helped me with one of those. You know, Ken, when we did the Deep Energy Retrofit book, and we have all those details available. It's free on our website.

The Mass Save paid for it. There was a pilot program where they were trying to teach contractors in the state. It was not ready for prime time. Okay, so it got a little abandoned. But the Solutions Center, all the details on that, the DOE Solutions Center, um, and You know, I think it's time is going to come.

And so, I just think we have to spread the word. I think that's what it takes. You know, from my neighbor going, what the hell are they doing? When we did the house in Westford, uh, we used EPS for that, um, originally. For the, covering the cube, and we called it the biggest beer, beer container, or, yeah, and, and, cooler, thank you, beer cooler in the country.

And, you know, we left it like that for about a year, so everybody, left everybody wondering, what's going on there? So, I mean, I guess for people to see it. And. And Zach and everybody that's, Zach Simke and the, uh, the Passive House Accelerator, telling the story, getting people to know, it's not that hard. You can do it.

It's not that expensive. You can do it. You just have to have the will, and I think the more people that see that it can be done, the more it's gonna happen. That's what I think. Thanks, Ken. Okay, um, I saw this

Thank you. So I just want to say, if you're counting refrigerant leakage for your carbon emissions, then you should recognize that all the carbon emission calculations that I've ever seen don't include the natural gas leakage. The natural gas leakage that's reported for, for instance, Massachusetts, which is the state that we both live in, has been measured to be at least double that by Nathan Phillips at BU with HEAT. They have done all these extensive mapping.

So when I've done operational carbon footprints for clients, commercial clients, you count that. So I could have gotten more credit, right? I can show it two ways to them because in Massachusetts, currently, 65 percent of our power comes from natural gas, which was, I think, a mistake. But that's another story.

And carbon emissions are counted as zero for solar, wind, hydro, and nuclear. And if you believe that, Joe has bridges that he's got a stack of with the pages out of order that he'd like to sell you. So, if you're going to count secondary things that actually do count, count them all. Okay, that's really critical here.

Yeah, and then my question is the Nessie keynote this year was deep energy retrofits are too expensive. We don't do them anymore. What's your thought about that? My thought about that and Rachel's going to talk here, she's up there. I love Rachel and I know the message was very well received and I think, you know, the carpenters, the master carpenters and the people that are working, they think it's too hard and too expensive, and I think we can be in two different spots at the same time.

I think, Rachel, you're going to correct me if I'm wrong, but you were trying to reach more people. In an affordable way, and that was the way to affect what was going on. Rachel. Turning it over to me already. I am. So, um, you know, I was sitting here thinking, Betsy, if I should get up and, and say something.

I don't know how I, how I could not, because you came to the exact opposite conclusion. And your carbon analysis at the end, and there's, there's, I mean, our time frame was 30 years, um, so, and there's a lot more uncertainty, obviously, the further that you go out, but, you know, for those who weren't there, Big Meister was a pioneer of deep energy retrofits, and we have since scaled back.

Um, investing, um, and sort of thinking about the balance of how much we should spend on load reduction versus how much we should spend on electrification a little bit differently. And so, we now do what we think of as more sort of a, a moderate retrofit, which you were calling essentially weatherization, air sealing and insulating as best as we can within the building shell.

And then rather than taking off roofing and siding and adding, you know, in your case four inches of foam or whatever, it's going to be wood fiberboard now instead of doing that electrifying. And our 30 year carbon analysis showed that, um, which was very different than yours, so you should, you and I, we should get together and look at those numbers.

That it was, um, and even when we corrected it, Mark, after you said, I don't know if you saw that, that right, we, so we have, we have, we've done a blog, Brendan did some updated analysis, and it's up on Nessie's website. That the cost per kilogram of carbon saved was still, was better over a 30 year time frame for our approach.

Now, again, so much uncertainty. Um, but, so I think it's, I think it's an open question. I do too. It's not one way or the other. It's not. And so, I just, you know, we're not on opposite sides. Nope. We're trying to figure out what the right thing to do for existing buildings is. And I should also say for folks, um, But I'm only talking about homes, like the home, the single family homes that we work on.

I'm not saying anything about multifamily buildings or other types of buildings. Anyway, this is, so thank you for that, for the analysis that you've done. And I know you said you, you had hoped to call me before you did, did the presentation, but we need to connect afterwards. Yes. Alright. , come back to the house.

We're dancing and singing and eating. It does really well in that atmosphere to talk. Quick question. Oh, Marcus. Patsy, um, we keep being challenged to come up with innovative, uh, retrofit ideas that are like, you know, maybe borderline crazy. Um, and, uh, I, uh, four years ago I tried to do what you'd done when I recited my house in Denver.

area, Litterton. And, uh, I could not find a contractor on the residing, uh, business that, uh, would not, uh, would even consider doing it. Um, and I said I would hold hands. I have, uh, you know, myself, my own experience and the experience of other people either from Owens Gorina or even yourself to ask. Um, and, uh, it got to the point that I, I got threats of being fired as a, as a customer.

Uh, so, like, find somebody else, uh, to do your siding job if you want to install the foam in this, uh, 1974 house. Uh, which needed reciting because of a damn woodpecker that I did not, um, I did not kill, so you all know. Um, I was very afraid of being deported at the time because I was not a citizen. And, uh, now, now I guess I would just be.

we'd be just fine, you know, we could marry each other. But, but I guess my question and, and the challenge that I think we think, I, I, as you know, I think this is a beautiful work. How do we get the siding folks to actually own this retrofit? In my opinion, we have options. We have foam, we have mineral wool board, heck, we have even duck board, if that's the way we want to do. But that's not being done, and it's a challenge that I think all of the people in the room have to consider very, very seriously. How do we actually get somebody to own that business? Because the siding folks, at least the ones that I know, do not believe that that's their business. Thank you.

I agree with you, Marcus, and it is incredibly difficult. And again, I'm feeling like this is going to be a wave and soon coming forward as we're really trying to worry about carbon and energy. That there, we're going to see more of this happening, and I think it's going to happen naturally. Everybody has a home. Everybody can take the position and say, "I'm looking for a hero. I'm wanting somebody that, I'm going to replace my siding. I want you to put on the insulating sheathing." With the National Grid program as well as with the NYSERDA one, I think you got a rebate if you did a certain amount of wall area and roof area and, you know, that helped with the process, but that's not the whole thing. It's really about speed and contractors making money and not losing money as they're trying to do something different. So, I feel like it's going to be a process. I just feel it's going to take time. But, you hit the nail on the head.

Betsy, I have one more. We, we just did a project that started out as a simple addition but became a deep retrofit. And the biggest complaint I get from the builders is, when is the fastener company, the company's going to get up to speed and have fasteners that actually penetrate four layers of one-inch foam. And, you know, it's just, yeah, they still, the builders fast and master. Yeah. Okay. Yeah. Fast and master. That's, we had a whole like, where do we get these fasteners from? We can't get them. Excellent. So they don't screw you over. I got it. Thank you.

Can I just say one thing real quick? Um, I'm listening to the conversation and I think it's just Uh, fantastic. We're thinking about those same things at DOE, et cetera. But the thing that hit me the most about Betsy's presentation is she did this for her daughter. That the value proposition that we have to push harder on. Because we're, we're, you know, I was hit by the 100 a square foot. And I was thinking, oh, shit, man, that's buying a whole new house. Basically. Oh, really? Yeah. Not anymore. Well, Not anymore. In some neighborhoods. But you, but you know what I mean. Yeah. That's a lot of money. And most families in this country can't buy a new house. They can barely afford their own house. So, how do we... I think that's why Rachel is doing what she's doing. So these things are really important and they're important not just because of the money and the environment. They're important because of our families.

Yes, and yes, and um, you know, making an environment, ultimately that house is gonna have another three occupants, that these are people with disabilities. They, you know, and I've been making it work so that they're all gonna have a comfortable space, and we'll share it, and it'll be ten people, and, um, that's gonna be a great thing, and these vulnerable population that they are won't have to worry about being cold, having mold, infestation or any of those things.

So five starfish, ten starfish. Andy, wherever you are. Yeah. That 5 percent leakage comes out of a British study where they actually measured some of this stuff. With the refrigerant you're talking about. Of refrigerant, and thank you for including that because it often, I've never seen it included in a carbon stack like that, so that's great, and it really needs to be. Yeah. It does come out of a study actually where they looked at it, and they even went as far as different kind of connections having different leakage rates and so on. And again, Schuyler made this great spreadsheet that does that, and he, he, I didn't know that, but he, I, I learned from Schuyler last night. So that was good.

The other thing is if you add in the methane leakage that's part of exploration, fracking, drilling, and transporting, it nearly doubles the GWP impact of natural gas. Oh. Yay. Another extra score. Woo! Am I a winner yet? Okay, Betsy, you mentioned your buyback rate with your PV. Yes, and that's something we've been dealing with for a long time and anticipating what, you know, it's going to happen in the utility world, right? So you talked about storage and dispatchable loads that can be scheduled. And then Also related to zeroing out our loads, we need to zero out our loads to the property line. And that includes what's in the garage. So part of our electrification efforts, including our transportation, it's coming faster than anybody ever expected.

And so when we do this math about zeroing out our properties, essentially, we really need to start adding that in. I see a lot of efforts where we're calculating how much PV we need to zero out our house. But we should include the hot tub that's in the backyard and other things, right? Well, we should include our transportation. Um, and it's totally schedulable. You can, you know, if you have time of use rates like most of the world does, we don't yet. You can, I can schedule both my electric cars to charge at a certain time. When, when the sun's shining and I'm making a bunch of power, or when the utility rates are lower. So I just want to plant some seeds here that, we need to start talking about that as part of our... Yes, thank you, thank you, thank you.

The car charger is coming, um, as soon as somebody who's gonna live there has a car that needs charged. Right now it's walkable, which is a good thing about it. You can get everything you need just by walking or taking the train, but that's a good point, and we could store energy that way too. Okay, I'm going to get an electric portion. Well, um, Thank you very, very much for a spectacular presentation. And, um, for all of you, let's go. Thank you

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