Isabelle Nagel-Brice cover photo

Figuring out what you need for a tiny house can be really confusing. Returning guest, Isabell Nagel-Brice has been working with 475 Building Supply, a company that sells high-performance building materials. In this episode, Isabelle breaks down which materials will help your house breathe properly, ventilate well, prevent mold, and just be a healthy tiny house to live in. She shares the names of these various products and explains what exactly they do to make your tiny house a healthy tiny house.

In This Episode:

  • What is Intello Plus and when is it applicable?
  • Why is the Solitex Mento 1000 great for outdoor builds?
  • How an air exchange system works
  • Thermal bridging and condensation issues
  • Cold climate? This is how to build your floor
  • Spray foam vs vapor-open insulation
  • How much building science should you know before moving into a tiny house?
  • Lessons learned from 5 years of tiny living
  • Why these tiny house trends may not work for you

Links and Resources:

Guest Bio:

Isabelle Nagel-Brice

Isabelle Nagel-Brice

Isabelle built her own tiny house and has been living in it full-time for almost five years. She now lives in her tiny house on property she purchased with her childhood best friend (who lives in the “big house” with roommates). They've created an urban homestead and gathering space with other landmates, a huge garden, chickens, and bees. Throughout her build, she focused on environmentally conscious materials stemming from her history with natural building and ultimately became inspired by Passivhaus designs, specifically. As a result, she founded A Tiny Good Thing to offer healthy tiny house building kits and hourly consulting to guide folks through the various stages of their builds. She has worked with builders all over the country to build high-performance tiny houses with quality materials that have less of a carbon footprint, don't off-gas toxic chemicals, and therefore confront climate change through the build environment. Isabelle is personally committed to having less of a negative environmental impact and wants to encourage others to do the same in building and life.




This Week's Sponsor:

Precision Temp Logo


PrecisionTemp is making one product to solve two issues that I know everyone deals with in a tiny house: running out of hot water and heating your tiny house. PrecisionTemp has made the amazing TwinTemp Junior propane tankless water heater, which provides unlimited hot water for your tiny house and hydronic heating. This means you get warm heated floors, so there are no cold spots. It's designed specifically for tiny houses and features whisper-quiet operation as well as high efficiency. If you want more information on how PrecisionTemp can help make living tiny easier and more comfortable visit While you're there, use the coupon code THLP for $100 off the TwinTemp Junior plus free shipping.


More Photos:

Isabelle moved from Bend, OR to tiny-house-friendly Portland, OR

She's been living tiny for about 5 years now

Doors that open the back of the house are cool, but maybe too cool for cold climates


Isabelle has a cozy workstation and sitting area

Isabelle's bees provide plenty of fresh honey

She insulates the hives in wintertime


A completed Healthy Tiny House Kit build by chickpea_yogi on Instagram

Isabelle's well-stocked and tidy kitchen

The sitting area becomes a guest bed!

Chickpea_yogi's Healthy Tiny House Kit build in progress


Isabelle Nagel-Brice 0:00

They were realizing that under their builtins it was just like mildew and mold everywhere. And so they were reaching out and calling me saying like, "First of all, why is this happening and what can I do?"

Ethan Waldman 0:15

Welcome to the Tiny House Lifestyle Podcast, the show where you learn how to plan, build and live the tiny lifestyle. I'm your host, Ethan Waldman, and this is episode 182 with Isabelle Nagel-Brice. Isabelle Nagle-Brice is actually a returning guest. And in this interview, we talked through the materials, the high performance building materials that will help your house, prevent mold growth, breathe properly, so have good ventilation, and just be a healthy house to live in. Isabelle has been working with 475 Building Supply, which is a company that sells high performance building materials and figuring out what you need for a tiny house can be really confusing. So Isabel is going to break it all down with us. She shares the names of these various products, and explains what exactly they do to make your tiny house a healthy tiny house. great conversation, really helpful information and I hope you stick around.

I'd like to tell you about the sponsor of today's episode PrecisionTemp. PrecisionTemp is making one product to solve two issues that I know everyone deals with in a tiny house, running out of hot water and heating your tiny house PrecisionTemp has made the amazing TwinTemp Junior propane tankless water heater, which provides unlimited hot water for your tiny house and hydronic heating. This means you get warm heated floors so there are no cold spots. It's designed specifically for tiny houses and features whisper quiet operation as well as high efficiency. If you want more information on how PrecisionTemp can help make living tiny easier and more comfortable. Visit While you're there, use the coupon code THLP for $100 off the TwinTemp Junior plus free shipping. That website again is coupon code THLP for $100 off the TwinTemp Junior plus free shipping. Thank you so much to PrecisionTemp for sponsoring our show.

All right, I am here with Isabelle Nagle-Brice. Isabelle built her own tiny house and has been living in it full time for almost five years. He now lives in her tiny house on property she purchased with her childhood best friend who lives in the "big house" with roommates. They've created an urban homestead and gathering space with other land maids a huge garden chickens and bees. Throughout her build she focused on more environmentally conscious materials stemming from her history with natural building, and ultimately became inspired by Passivehaus design specifically. As a result, she founded A Tiny Good Thing to offer healthy tiny house building kits and hourly consulting to guide folks through the various stages of their builds. She has worked with builders all over the country to build high performance tiny houses with quality materials that have less of a carbon footprint, don't off gas, toxic chemicals and therefore confront climate change through the built environment. Isabel is personally committed to having less of a negative environmental impact and wants to encourage others to do the same in building in life. Isabel mango rice, welcome back to the Tiny House Lifestyle Podcast.

Isabelle Nagel-Brice 3:37

Yes, thanks for having me back.

Ethan Waldman 3:39

You're very welcome. I'm excited to jump into these high performance building materials and kind of talk about what they are and how they work and why you know why people might want to use them. But before we do that, I'd love to just hear a little bit more about how your tiny living journey has evolved since we last spoke, I think three years ago.

Isabelle Nagel-Brice 4:03

Yeah, it's changed quite a bit. I had moved to Bend just before we spoke last time and living in Central Oregon, and I was living on a beautiful homestead 87 acres with views of the mountains and on the river. And I realized that it was kind of an isolating living experience, just moving to a place not knowing anyone and living outside of town. When I first moved, I was reported to the zoning department of Bend and had to move on to this farm and through that process, I realized that I really wanted more community in my life. And I also realized that I wanted to live somewhere where tiny houses were legal. A lot of people live in tiny houses illegally and have been for many years and I think it takes a certain like personality or acceptance of that. lifestyle to feel comfortable with it. And for me, I realized once I moved up to Portland where tiny houses were allowed and very much accepted in the neighborhood that I'm in, I felt a huge weight had been lifted. And I actually moved to a property, just 12 blocks from where I live now and ended up not being an ideal living situation due to the other people that lived on the property. And it was a little bit of like a kick in the butt to find my own land. And I was fortunate enough to team up with my friend of 20 years, and we bought this property together by dropping letters in mailboxes, pictures of flowers and sweet note and posting on next door. And so we bought this home just over a year ago, off market, they never listed it. And we were super fortunate because we wouldn't have been able to find a property that had everything that we needed. That was a quarter acre and had room for the tiny house, and especially not in this market with all of the competition. Yeah. And so that's where I'm at now. And yeah, I feel really excited to be putting down some roots here, we put in a big garden, and I have my bees, and it's really opened up my experience and quality of life with Living in the tiny house, I think.

Ethan Waldman 6:22

Yeah, that's awesome. I think it's, it's interesting that you kind of experienced tiny living as this kind of solo, isolating experience, it sounds like, and then kind of realize that even though the house is tiny, that you really did want to be in community. And I think that it just tiny living lends itself so well to that.

Isabelle Nagel-Brice 6:46

Yeah, absolutely. And just having a space where like, if I have a hard day or something, I can go over to the main house and have dinner with with my really close friends. And we have barbecues lot and we bring people to the property. And that has really been like a savior throughout this pandemic as well. Because I think that in the beginning when I was living at the other spot, and COVID had just hit and you know, I wasn't working as much and I was just hunkered down in the tiny house that felt really small.

Ethan Waldman 7:17

Yeah, yeah. So moving into the the kind of the performance building materials. There's a company called 475 building supply that I think I saw a talk that they gave at Yestermorrow, which is a building school here in Vermont. Yeah. And I've always had it in the back of my mind to have someone from 475 on the show. And my understanding is that, you know, a lot of the Most High Performance building materials are actually coming out of Europe. Yeah. And so they actually import a lot of these products and are a major supplier for high performance building in the United States. And do you work for them? Or can you explain what your relationship to 475 is?

Isabelle Nagel-Brice 8:04

Yeah. So when I was building my tiny house in Colorado, I was connected with a Passivehaus consultant in builder, Colorado, and he uses many of the materials from 475. And when he was teaching me this different style of building and how to mitigate moisture issues, how to address thermal bridging with my tiny house Personally, I realized that this information wasn't out there. It certainly was not in the tiny house movement at the time, like seven years ago. And it was really hard to source these materials. And I basically just got lucky by living near near this man Cody Farmer who brought in materials from 475 and then another company that I was able to source my exterior insulation from, but I realized that for many builders all over the country, it's not as easy to source those materials. And so Cody and I actually put together kind of a branch of his company that focused on tiny houses specifically and we started to put together the healthy tiny house kit and we're still very close we text often but I ended up branching off and starting A Tiny Good Thing and just honing in on like off grid living and applying these materials to van and bus conversions like RV renovations and then of course tiny houses and ADUs. I've worked on Adus as well. And so at that point I reached out to 475 and said you know i'd love to be a distributor I've been working with your products I have them in my tiny home that I'm living in and that I've been living with. And so I became a distributor for 475 so I can sell most of their products and I sell select line of their products on my site

Ethan Waldman 10:01

Cool cool all right so you you have a cool relationship with this company and you've you've and sell their products that apply well to tiny houses.

Isabelle Nagel-Brice 10:13

Yeah and they often get calls and inquiries or tiny houses specifically and they'll send those over to me because I offer like all natural sheep's wool insulation and composting toilets and other products and can really speak to these people about how to build on a trailer Foundation which is quite different than standard foundation. Yes. So I was

Ethan Waldman 10:37

hoping we could just talk about some of the items that are in the, in the healthy tiny house kit. One of the big ones that I've that I've heard talked about is intello plus

Isabelle Nagel-Brice 10:52

what is intello plus so it's an interior air barrier, okay. So it helps to protect against condensation I really push this product for like container homes van and bus conversions that have an exterior steel shell where you don't have control over the exterior but you do on the interior so it has a lower vapor permeability which means that in higher percentages of relative humidity indoors it won't allow that that condensation to get into the wall system and so it's really ideal for small spaces in that regard. Right The other aspect is that you can create a completely sealed air barrier on the inside of the home and you know with the bus conversion for example you know you have like an exterior shell but it's probably not airtight got it

Ethan Waldman 11:50

got it and then so this Intel of loss basically prevents that moisture from getting into the wall where it will then hit that cold metal shell dance and then you have one run wall

Isabelle Nagel-Brice 12:03

yeah and run down into your sub floor and etc Exactly. And so

Ethan Waldman 12:09

then I guess the other product that maybe is the the companion to this is the Solitex Mento 1000

Unknown Speaker 12:17

Yeah, so the Solitex is an exterior weather barrier Okay, many people building tiny houses are building outside and often like DIY builders are taking a longer time to build so this product is really perfect because it has really high like UV protection so you can have it out exposed for three months and it's still going to function properly. Additionally it can withstand 33 feet of water pressure like in a column which is a huge amount of pressure which you would you know never have but let's say that you build your sub floor and you put down the Solitex Mento and then it rains really hard or something you know I've had clients call me freaking out and it's not not a problem at all. And the technology but behind this membrane is that it drives vapor outside when you have a slight pressure difference. And it's it's based in like a building sciences that there's like a molecular chain that it pushes that pushes the vapor out. So rather than having a membrane that's porous, it allows the vapor to escape and is also airtight.

Ethan Waldman 13:34

So this Intello Plus the one that we talked about first that goes on the inside of your studs, basically between your finished wall material and your studs, right?

Isabelle Nagel-Brice 13:49

Yeah, exactly. And you can also use it if you're doing blow in insulation. So I'm a huge advocate for either blown in cellulose or blown in sheep's wool because it's just gonna get into every little crevice and therefore it's more effective. And so you can put your intellicus up and then you can blow in your insulation so it serves two purposes

Ethan Waldman 14:13

Okay, like creates those pockets between the studs for your insulation to fill.

Isabelle Nagel-Brice 14:19

Yeah, and if you're using that insulation, you just put it up after you've done your bad right.

Ethan Waldman 14:25

And okay and so then the Solitex Mento then goes kind of on the outside of your sheathing, right

Isabelle Nagel-Brice 14:33

goes on the outside of your sheathing and I have different tapes that I include in the healthy tiny house kit. So there they are for taping the seams taping any penetrations so that you can maintain that air tightness and then also, you know there's always a little bit of origami involved with going around the wheel wells and making sure that that weather barrier is taped correctly to the trailer. All, you know, all the trailers are a little bit different. And so addressing that and focusing on, you know, how do we still create an airtight envelope? Totally, with all of the tapes and membranes? Yeah, and

Ethan Waldman 15:12

it is, when you're working with these materials, I would imagine that it could slow things down a little bit in the sense that anytime you penetrate the materials, you have to tape, you have to tape them properly. Otherwise, you've got this amazing material. But then if you leave a hole in it, the vapors gonna get in or out or, you know,

Isabelle Nagel-Brice 15:34

yeah, right. You're just yeah. Basically, if you're having like wires coming through, or your electrical boxes, you want to make sure that you're taking to those and air sealing those. Otherwise, you know, you're you don't need to do an airtight envelope.

Ethan Waldman 15:50

Yeah. So if you if you use these two products, you're essentially creating an airtight interior airspace. Right?

Isabelle Nagel-Brice 16:01

Yeah. And I like to say that you're separating the exterior climate from the wall system, which has its own thing going on, and then also the interior of the house, so you're completely separating. And therefore you're able to have more control over your ventilation, and your moisture management. Yep. You know, tiny houses regardless are going to be built really tight. No, like, no matter what materials they're using, they're so small, with our conventional building materials, it's still going to be tight. It's not going to be airtight, you'll still have air leakage. But you don't really want to be breathing the air that's coming through those cracks in your wall system or in your subfloor. And so this gives you full control over then including your ventilation, and having filtered fresh air continuously coming into the space.

Ethan Waldman 16:57

Right. And that is you work with the Lunos system, right?

Isabelle Nagel-Brice 17:02

Yeah, so I'm definitely an advocate for the Lunos ventilation systems heat recovery ventilation, essentially, it creates, since since it's a single wall penetration, like the Lunas e squared, for example, there are two units. And depending on the plan of the house, all all advise where to best locate these, but typically a tiny house of like 24-26 feet in length, we'll have one e squared pair, so you put one on one end, one on the other. And they switch off bringing air out of the house, the stale air inside of the home, and then bringing in filtered fresh air. So I like to look at it as it's kind of creating, like your house is becoming the ducting system, and it creates optimal airflow that way, and then including the Lunos ego in the bathroom, which has a single wall penetration that's divided in the inner tube, and it brings in air and exhausts at the same time. Nice. And it has a function that you can turn on to for both sides to exhaust so it can replace the back end. And I think that that's really valuable to have. And then the rest of the time, it's just constantly refreshing the air in this space and just adding to that nice cycle of air and the whole home.

Ethan Waldman 18:25

What's the cutoff point for like in terms of square footage, when you need to go from the ego? For the bathroom that would that do the whole house? Are you

Isabelle Nagel-Brice 18:40

Yeah, and a smaller, tiny house like 20 foot or smaller, that's fine as long as the bathroom doors open most of the time. And then in a larger home, I like to include the Lunos squared. I mean, Tiny Homes inside have fairly tall ceilings, you know if they have a loft or something so you have a little bit more cubic feet of air in there that you want to cycle through. Yeah. Very cool. Very cool. So there are

Ethan Waldman 19:09

I've had people on this podcast to talk about it. I had a Canadian building inspector who was kind of sounding the alarm about how unhealthy tiny houses can be and how many mold problems he's seeing. Yeah, I interviewed a dweller somebody whose tiny house was, I mean, this is a vehicle term totaled, you know, just from water damage to the sub floor. They they basically sold the house at a big loss and are doing something else now. What have you been seeing in terms of, you know, are people coming to you kind of after the fact saying like, help? Yes.

Isabelle Nagel-Brice 19:48

Yeah, I've been consulting. It's funny. It's not funny. I've been consulting every winter. Usually not in the summertime, which makes perfect sense. Yeah. Every winter. I Have people reaching out. And this past winter, I had several clients that I worked with who had already built their tiny houses had been living in it for, you know, a couple years, probably definitely a year. And they were noticing mold and mildew issues. And they were realizing that under their buildings, it was just like mildew and mold everywhere. And so they were reaching out and calling me saying like, first of all, why is this happening? And what can I do? And you know, the harsh answer is that you should have built your house differently.

And I can speak from personal experience that I should have built my house differently. I know exactly how I should have done it. And I've been living in it for five years. And now I know what to keep an eye on in my home. And I know what to do to mitigate those issues, but it's not going to completely eliminate it. Because, you know, it's like putting a bandaid on rather than addressing the root cause Yeah, so I got some pretty gnarly pictures this past winter of people with condensation on their floor, under the couch, for example, going along every single trailer beam, it was really obvious. And I put a blog post up about it, because talking about thermal bridging, but to be able to actually see that inside of a home is pretty intense.

And most tiny houses are built without addressing that thermal bridge between the trailer and the sub floor. And the trailer is steel. So it's a huge conductor of temperature. And when you have a cold climate, and you have high humidity inside, you're going to get condensation on those cold areas. And it's usually under builtins. And under cabinets where you're not getting enough airflow either. And then additionally, I actually had it tiny house in my neighborhood I just ran over when they gave me a call to see it for myself. And they had tons of mildew all over like this one area of their wall. And I realized it was right near the wheel well. And they had a built in bench next to it and I opened up the bench. And sure enough, they didn't insulate well, and the steel was exposed. And so that house definitely should have been built differently. And they may have to take all of that all of those buildings out and insulate it and put them back. They also installed a Lunos ventilation system just to have fresh air most tiny houses don't have continuous fresh air. I just worked a tiny house festival last weekend, there probably 10-12 tiny houses there and there wasn't a single HRV Yeah, I'd like to tell you

Ethan Waldman 22:52

a little bit more about the sponsor for today's show. PrecisionTemp. One of the hardest things about being in my tiny house in the winter, is that the floors are really cold. And I could have solved that problem by adding more insulation. But the reality is that a tiny house on a trailer is always going to have cold floors, or much colder floors than you're used to if you are coming from a house that has a basement or is even built on a slab. So the PrecisionTemp TwinTemp Junior propane tankless water heater can actually help solve this problem because you can install heated floors in your house. And you can do it with the same appliance that provides you with unlimited hot water to the TwinTemp. Junior really does solve two issues with one appliance, which let's be honest, in a tiny house, space matters, cost matters and just being more intentional. So you get to use one appliance for two purposes. Right now PrecisionTemp is offering $100 off the TwinTemp Junior plus free shipping. When you use the coupon code THLP at checkout, head over to their website For more information on how PrecisionTemp can help make tiny living easier and more comfortable. And while you're there, be sure to use the coupon code THLP for $100 off the TwinTemp Junior plus free shipping. Thanks so much to PrecisionTemp for sponsoring our show.

It's unfortunately, it's it hasn't become common practice that tiny house builders don't give people the option or put it another way. I think that builders have a responsibility not to present ventilation as an option to their clients but as a require. Yes, it's like you wouldn't build a tiny house without insulation. couldn't do it without ventilation either.

Isabelle Nagel-Brice 24:55

Absolutely. And I would say the same for the sub floor. You know, the fact that builders are building directly putting their sub floor right on top of the trailer, maybe a little bit of closed cell foam, but that's it. That's creating these moisture issues. Yeah. And, and I also have the the I had the special opportunity of fixing my gray water lines under my house before I moved from Colorado to Oregon and pulling out a screw and seeing two full cups I would say of water come out of my trailer subfloor like under the flashing. And I freaked out, I was really, really surprised. And I thought that I had a plumbing leak that I wasn't aware of. So I ripped open the wall in my bathroom, it was right above there didn't have a plumbing leak, I pulled all of my flashing down under my trailer which you know, the trailer manufacturer had installed. And I could see under my bathroom condensation along that metal flashing under every single trailer beam. Wow. And I realized that it was because I put a radiant heat mat under my tile in my bathroom just to add a little heat in there. And when you have a temperature difference, so extreme when you have the cold trailer, and then you have like an 85 degree, you know, radiant heating that right there, you're going to get condensation and I had put foam and spray foam in my trailer and reclaimed foam. And it didn't have a way to like vaporize and escape. And so it just stripped down, it was just being held underneath. Wow. And so that also informed me to build the entire like trailer sub floor foundation differently. And to use vapor open insulation and vents and then build up on the trailer to break that thermal bridge.

Ethan Waldman 26:42

Okay, yeah, that's actually I'd love to dig into that a little more. Like when you are working with a client, and they haven't built their tiny house yet, and they are going to be living in a cold climate. what's what's kind of the ideal floor system on a trailer?

Isabelle Nagel-Brice 27:01

Yeah, so basically, before they get the trailer, I advise on this different plan because they're going to lose a few inches of head space. So if they're doing like steel framing, and they're sending their design out, or you know, just doing all of their plans, they need to address that. And so we talked about that. And then when they get their trailer, they put little like screened events in every day of the trailer, usually two in every day. And then they put vapor open insulation in that in those cavities. So that's either well or, like mineral wool, and they fill that cavity. And then they

Ethan Waldman 27:46

those vents in the trailer those face down like they're in the they're in the belly pan of the trailer or they like vertical.

Isabelle Nagel-Brice 27:55

Yeah, they're in the belly pan. So they're at the at the bottom, and then you put the vapor open insulation, you build basically like a wood frame on top. And you break the thermal bridge between the trailer and the wood framing a little bit with some high density foam. But you only put that foam along the beams and the flange of the trailer so that you have airflow throughout the cavity. And then you pack between those sleepers, you pack in some more vapor open insulation, and then you put your soul attacks down. And you can put your Solitex down before that if you're not using like treated lumber because essentially that wood is going to be outside of your built environment. And so you're really separating the trailer and the sub floor from the rest of the house. If that makes sense. And then your solar Tech's mento goes down, and that goes over the wheel wells underneath your framing that goes over and it wraps up and tapes underneath the sole attacks mento that comes down from your walls. Okay, and you take that scene,

Ethan Waldman 29:07

then your your sub flooring goes on top of the sole attack.

Isabelle Nagel-Brice 29:11

Yeah. Wow. Yeah, that's cool. Yeah, and so then if there is condensation that happens inside of the cavity of the trailer, your insulation will vaporize it or it will drip down and be able to get out of events. And so the whole idea is you know, if you wash a plate and you set it on a counter without a towel underneath it, that water is gonna pull there and have no way to escape. But if you put it on a towel, that towel will absorb some of it and will vaporize it.

Ethan Waldman 29:46

Got it so and when you say vaporize it kind of just dispersed the water and then it evaporates.

Isabelle Nagel-Brice 29:51

Yeah. And then it's not airtight. It has those vents underneath. So

Ethan Waldman 29:57

right. One question And that I get a lot from from people is like, specific help with? How do I frame and insulate properly over my wheelhouse?

Isabelle Nagel-Brice 30:12

Yeah. And I know it's such it's a challenge for sure.

Ethan Waldman 30:15

Yeah, with this being a podcast, it's like, this is such a visual thing. But I wonder, you know, do you have any words of advice?

Isabelle Nagel-Brice 30:23

Yeah, I like to leave a little bit of a gap over the steel wheel well, and you have the soul, the text mental coming up, and under and around that framing, and then you insulate inside of that frame that goes over your wheel well. And I am an advocate for vapor open insulation all around so that you would do that there as well. And then some people will slide a piece of foam in there, and they can tape it closed, they can tape the weather barrier to the trailer, or some of the trailers come with like a built in flange that goes around. Yeah, you can take to that. And then in cold climates, I also really recommend that my clients put exterior insulation on their entire home, because the wall system is so narrow. To begin with, you're going to have thermal bridging through your studs. So adding like an inch and a half of exterior insulation makes a really big, yeah. And on the roof as well.

Ethan Waldman 31:23

So if you do that, that our insulation or that extra insulation, does the mento go over that, or does it go between? Does it go between your sheathing and the insulation?

Isabelle Nagel-Brice 31:35

Yeah, I've seen it done both ways. Okay. But I think just, especially for someone who's a DIY builder, I think it's easier to have it just go over the sheathing. And then you use exterior insulation that's also vapor open. So like rock wallboard or wood fiber. But if you put it inside this old text mento, then it's it's fully, like protected. And then you can do a rain screen, and then your siding. So with a rain screen, you get a little bit of ventilation between there but yeah, I mean, either way, I think if you wrap it in, it's gonna really keep it like clean and right now it's not gonna get moisture in there anything, right? One?

Ethan Waldman 32:18

You know, I think that that rock wall insulation is becoming increasingly recognized as a good choice for tiny houses. I'm curious if you can speak to, you know, if I was a client, and I was like, Oh, I want to do spray foam, or somebody told me I should do spray foam. Mm hmm. What, you know, what do you say? How do you make the case for a vapor open? insulation versus spray

Isabelle Nagel-Brice 32:43

foam? Yeah, thanks for asking that question. Um, I have a lot of reasons. So I'll say my personal number one reason is that I chose to build a tiny house and be in the tiny house movement, mostly for environmental reasons. And I didn't want to use materials that would, first of all off gas, chemicals into the atmosphere or into my own breathing space. And I wanted to use materials that could biodegrade eventually, when the house was taken down. And so spray foam is extremely toxic as it's curing. And you know, if you look at pictures of people installing it, either fully covered, and they have their own ventilation, and they are not, you know, dealing with this material firsthand, it's because it's really toxic.

And the other reason why I don't think it's ideal for tiny houses is because if it doesn't cure properly, like if it's not in a manufactured setting, where it's like in a warehouse that's like temperature controlled and humidity controlled, then it's possible that it doesn't fully cure and then it will continue to off gas into the home once you're in there. And there's definitely like people make the case that spray foam creates an airtight envelope. But when you're putting it into a tiny house, that's going to go down the road and it's going to move that spray foam for example in the subfloor, like in my sub floor separates from the steel beam and then you end up not having an airtight barrier and you have areas where condensation can occur and can move around.

Ethan Waldman 34:27

Got it.

Isabelle Nagel-Brice 34:28

And so vapor open insulation, like rock wool is I think it's so popular because it's easy to source and it's not that expensive. But the process that it takes to to produce it is extremely like energy intensive and you have to heat it up and spit it out similar to fiberglass. So I'm a really big supporter of all natural sheep's wool insulation because it's naturally mold and rot resistant. There's a reason why we wear it. When it gets wet, it's going to continue to keep you warm. And I just love working with it. I actually put it in my beehives in the winter to give them some insulation and airflow above there. So yeah, those are my feelings around spray foam versus paper of insulation.

Ethan Waldman 35:21

Nice. Nice. So with with the sheep's wool, is the R value of the wall kind of equivalent to a bad style. Insulation that's comparable. Exactly. And that's Yeah, are five ish per inch.

Isabelle Nagel-Brice 35:37

Yeah, for the bats for tiny houses ends up being like R-13. Yeah, a little bit more if you do the blow in Yeah. Yeah. And then most common exterior insulation is the mineral wall, the rock wall board, right? And then like do tax or there's other woodfibre boards that are coming out. Right, right.

Ethan Waldman 35:57

Another very popular building material in the tiny house world. I'm not entirely sure why it's so popular. I just think that they both kind of hit the scene at the same time. Is the the zip system sheathing. Yeah, that has so you see it on houses, it's either green or red. And essentially, it's billed as a sheathing that has a vapor barrier basically built on. And you just tape the seams. And you're good to go. No wrapping. Nope. Yeah. How do you feel about that product?

Isabelle Nagel-Brice 36:35

I think you know, it's popular because it saves you a whole step. Yeah. But it also is not like the Solitex Mento that's going to provide that, that moisture drive that vapor drive out outward out of the building. And so you're essentially if you do it, well, you're essentially wrapping your house in like a ziplock plastic bag. Yeah. Which if you have vapor open insulation and an interior membrane like intello, that's airtight, you can, you know, have some moisture flow, but it's not ideal. It's not as good as having the Solitex Mento on the outside. Okay, got it. Got it.

Ethan Waldman 37:17

That's a lot to think about. Yeah, and it's, you know, I encourage, I guess, I want to ask this question. I'm very familiar with it now. Because I've, you know, kind of learned a bunch when I built my tiny house. And then of course, I have my regrets that I there are things that I would want to do differently. And you know, you and I have both been steeped in this for a long time. But I think that it's easy for people's kind of eyes to glaze over, when they start hearing things about, you know, the dew point and vapor barrier and all these terms like, where can people? What do you How much do people need to get educated about this before, before they live in a tiny house?

Isabelle Nagel-Brice 38:04

Yeah, that's a good question. And it's a hard question to because when you're attempting to build or buy a tiny house, you have so many decisions that you have to make, and so many things that you have to learn that adding like the Building Science is, it's a lot, and it can definitely be overwhelming. Yeah. And that's really why I've started consulting and you know, it's mostly education. And, yeah, it can be as basic as like, on a really hot day, you take a beer out of the fridge, it's immediately going to condense in your hand in the air. And that's what happens in your house when it's really cold outside and warm in your house. So giving people like visuals like that, I think is really helpful. Um, and I think the more stories that come out of these tiny houses that are failing after a few years is really important. There's a lot of pride in the movement and especially with the DIY builders pride that they built their home correctly. And I'm like the first one to say, you know, my house was a full progression of my education and I can show you from like, you know, from the beginning to the end, and I can show you pictures of mold and mildew in my house and why that is. And so I think more stories coming out about that, that can really just show people what it's like living in a tiny house. Yeah, and I also work with people who have like health issues and like mold and toxicity issues and Lyme disease, and things like that where they're really sensitive or chemical sensitivities and so they're like, already a little bit kind of like on that more natural page and they want to build a home that's chemical free. And this is really the way to do that. Cool in our

Ethan Waldman 39:58

in our pre interview chat you mentioned that that you've learned a lot of lessons through living tiny five years or five years. Yeah, it sounds like you discovered that there was some flaws in the stub floor the floor plan and the insulation there. What are some other things that you've discovered through through living tiny for five years?

Isabelle Nagel-Brice 40:22

Yeah, I think also to make the point of not only am I live like in the same place with my house, but I've lived in different climates and that's really what has shown me how my house has dealt with the climate so yeah, like yeah, like Ben to Central Oregon and Colorado is really dry but then has these like big temperature fluctuations that can even happen in one day. So that's where I really learned about like the thermal bridging and then my worst winter with mildew in my tiny house was when I was in Central Oregon and I ended up putting in a wood stove in my house just to add some like extra heat because my propane heater wasn't producing enough and I sized up a little bit because I just wanted to like just last my house with heat and when it was like damp inside and just dry everything out and that has made a huge impact. And then I've also just learned about more about building science and about like having gas in your home and how there's studies coming out that showing that gas stoves are leading to asthma in children and most tiny houses are pretty dependent on propane for the off grid reasons Yeah. And and I am curious like how many tiny houses actually end up living off grid and now that I'm I've been on grid and I'm hooked up to shore power I got rid of my solar panels and I'm working right now on building like an electric induction cooktop with just like a small electric oven and getting out my propane range or that indoor air quality yeah I

Ethan Waldman 42:09

sounds like we've been on a similar similar path I feel the same about propane and also being alarmed learning about the indoor air quality issues and also just the fact that that much like I mean it's not surprising This is the oil and gas industry yeah that they have waged a 50 year disinformation campaign to market propane and gas to us that it's better for cooking and that you know cooking on electric is is lame or bad or not as good and yeah i agree it's it is a challenge the propane versus electric

Isabelle Nagel-Brice 42:52

yeah there's there's like stat like what you're saying there's like status associated with having a gas range Yep. You know people people buy a house and it doesn't have a gas stove and that's like you know on their con list right or something they want to change about it but really, the induction stoves that are coming out now are super efficient and really fast. So I'm excited to experience that and yeah,

Ethan Waldman 43:16

door you so your heating now is a combination of electric and wood

Isabelle Nagel-Brice 43:23

Yeah, I have an electric convection heater and when I was in Central Oregon I didn't have I had like 20 amps so I didn't have my full 30 amp hour Yeah, and so I couldn't run that backup heater and it was tough for a few months I would come home and turn on my propane heater and it would take like six hours to bring the house up to temp and it would be like 48 degrees when I came home yeah. And the wood stove is really quick and heats up the home really fast and you know not the best for indoor air quality they're having a fire inside of your space Yeah, but the convection heater in Portland mostly like keeps the house at 66 degrees pretty much through the winter

Ethan Waldman 44:11

is your wood stove does it get makeup air from outside

Isabelle Nagel-Brice 44:15

it doesn't I how I designed the flu I couldn't and how it installed in my house I couldn't access like the direct venting so I just always open up a window yeah every time I use it and honestly it gets up to like 8085 degrees in here really quick and we open like all of the windows and it's too much yeah and but it's it's kind of nice to have that like cycle in the winter. Just like refresh the dried out refresh the air and close back up

Ethan Waldman 44:48

again. Yeah, totally. Are there any other I don't know if you've ever heard the expression like sacred cows, but just things that that are common practice in tiny house building that you think need to be rethink?

Isabelle Nagel-Brice 45:06

Yeah. I've never heard that expression. But I like that. Yeah, I think one one design element that's really popular, our friend French doors that open out, I have them. And what that means is that they are on the outside of the frame of the house. And so the doors themselves are like on the outside of the threshold. And I think it's partially that and then it's partially like not properly breaking that thermal bridge between the bottom of the door and the trailer. And so I've seen numerous houses with major condensation issues that goes up the doors, and like rots out the wood or whatever it is. So that's not ideal. And I think it would be better to do like a standard door or to indent your framing so that it's not kind of like hanging out like that. Got it. And same goes for I mean, just air tightness in general, like install, like those, like garage, roll up type doors, like those just don't seal, right. And so I think that's a really cool trend if you're in a warm climate. But if you're in like a warm, dry climate, but otherwise, I don't think that those are a good application for tiny houses.

Ethan Waldman 46:33

Yeah, I agree. They are so cool. Just the way they let your entire house a wall of your house open to the outside. Yeah, but they do look like a heating nightmare.

Isabelle Nagel-Brice 46:47

Mm hmm. And yeah, I don't know if I can think of anything else. That's like common practice. That I don't recommend anymore. I mean, if I were to build my house again, I would, I would do all electrics, I would take all the propane out. Okay. And actually,

Ethan Waldman 47:05

I guess one last thing that I like to ask guests, or, you know, what are two or three resources that you recommend for maybe for learning more about building science and indoor air quality?

Isabelle Nagel-Brice 47:18

Well, I think that everyone should research Passivehaus design, which is just a design principle out of Germany. Yep. So just like doing a little bit of preliminary research and kind of understanding the concepts. Passive House design is like, the idea is that you're building a really efficient, high performing home that works for you. So the passive aspect is not that it's like passive solar like earthships or anything like that, but that the home has this continuous comfort level. And that's really what we want in any home that we live in. And tiny houses deal with this lack of comfort for various reasons, and how can we address that and just make the home more efficient and work like better for you. So I'm actually about to do a course a Passive House design like certification course that I'm really excited about. And I, I mean, I have a lot of like resources in the tiny house movement, which I'm sure people reference on your podcast all the time. I've been getting more into like the idea of land hacking and house hacking. So those are those are terms that are thrown a lot in like the bigger pockets podcast if you've heard of those. And I think that it really lends well for tiny house living just creating more alternative spaces. And so I've been listening to that podcast a lot. And I was just recommended a book called you are better things by Glenn Adamson by a fellow tiny house, er, and I'm looking forward to reading that. It's, it's all about, from what I know, it's about, like choosing belongings in your space that have like emotional value and that have, you know, multiple functions and that's all about what tiny houses are. Cool.

Ethan Waldman 49:18

Well, Isabelle Nagel-Brice thank you so much for returning to the Tiny House Lifestyle Podcast. It was great to catch up and I love what you're doing.

Isabelle Nagel-Brice 49:27

Yeah, thanks for having me again. So fun.

Ethan Waldman 49:30

Thank you so much to Isabelle Nagel-Brice for being a guest on the show today, you can find the show notes, including a complete transcript at Again, that's

Well, that's all for this week. I'm your host, Ethan Waldman, and I'll be back next week with another episode of the Tiny House Lifestyle Podcast.

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