The science of building better homes
We’ve all dreamt of that perfect home - something warm, inviting, and aesthetically pleasing. But, how often do we consider the science behind construction that makes a house not only a thing of beauty but also a safe and comfortable haven?
We recently sat down with Jess Kismet, a building science consultant who opened our eyes to the hidden factors some of us in the building and construction industry can overlook.
Windows: More Than Just a View
Windows can be our home's biggest liability when not chosen or installed correctly. They are like the gaping "holes" in our home's exterior that lead to unwanted heat gain and loss, affecting everything from energy bills to overall indoor health.
During her travels in Europe, Jess observed how they build all their houses in a way that here in Australia we consider “High-performance”. Europeans are building for more challenging climates, but we can learn from their building practices and how they pick and install their windows. Her advice? Invest in smaller, well-performing windows to minimise costs and enhance energy efficiency.
The Menace of Mould
As we pivoted to the topic of mould, Jess didn’t mince words. She stressed how prevalent and dangerous mould can be, sharing alarming statistics that almost 40% of Australian homes host some form of mould. She detailed how mould can be linked to severe health issues for those suspectible, like chronic fatigue and asthma, and went on to explain the biotoxins they emit. These often go undetected yet wreak havoc on human health. Mould, Jess argues, isn’t merely a cosmetic issue; it's a public health concern that requires more awareness and action from both builders and homeowners.
Building Strategies for Healthier Homes
Jess’s work underscores the importance of proper management of heat, air, and moisture in building design. She shared her extensive experience helping builders and homeowners achieve this balance. A significant part of her job involves educating both clients and builders about sustainable building practices. Her approach is pragmatic, yet she challenges clients to consider the long-term implications of cutting corners, especially when it comes to choosing builders who may not prioritise health-conscious construction methods.
Three Pillars for a Healthier Home
Jess left us with three fundamental takeaways to ensure a healthier living environment:
1. Quantify Air Tightness: Jess stressed the vital role of air tightness testing. Knowing the air quality and ventilation status in your home can lead to healthier living conditions and energy efficiency.
2. Manage Thermal Bridges: Properly insulating the frame and materials, especially steel, is crucial. Windows, often neglected, also play a significant role here and should be upgraded for better thermal performance.
3. Check Insulation: Ensuring insulation is installed correctly cannot be overstressed. It’s about vigilance and verifying performance to avoid compromising on comfort and safety.
Jess, through her building science expertise, aims to enhance awareness and practical application of science in building homes. Her dedication is clear in her personal pursuits such as her own podcast, The Building Sciology Poddie which further explores these themes.
We walked away from this conversation with fresh ideas and a reaffirmed commitment to integrating science into building practices. In doing so, we aren’t just constructing homes; we are creating healthier, sustainable environments for future generations.
LINKS:
Thanks to Hip Vs Hype for having us
Connect with us on Instagram: @themindfulbuilderpod
Connect with Hamish:
Instagram: @sanctumhomes
Website: www.yoursanctum.com.au/
Connect with Matt:
Instagram: @carlandconstructions
Website: www.carlandconstructions.com/
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Matt: [00:00:00] Have you ever wondered what it means to build with intention? Well, I'm Matt, and with my co-host Hamish, we are dedicated to pushing boundaries and building better homes. So we welcome you to join us on the Mindful Builder Podcast where we are committed to driving positive change in the building industry by surrounding you with experts in their field and being open about our lives as builders.
So join us on this mindful journey of construction by subscribing to the Mindful Builder Podcast. Please note that all advice provided here is general in nature and may not apply to every individual situation. It is important to consider your unique circumstances and consult with relevant professionals or experts for tailored guidance.
Use this advice as a starting point for reflection and exploration, and always trust industry professionals when making decisions. Jess, let's be brutally honest. If you could tell homeowners one thing about their living spaces that they absolutely don't want to hear. But desperately need to. What would it be and why are we so blind to it?
Jess: There are so many answers to this, but my mind just goes straight to [00:01:00] windows. They're costing you money if you don't get them right, and they are. Creating unhealthy spaces if you don't get them right. How, why, why are they
Matt: costing us money?
Jess: Well, they're the biggest hole in the envelope that there is. So there's, it's a lot of heat gain and thermal
Hamish: work.
Thermal wound, if you would. Yeah, yeah.
Jess: Yeah. Lots of heat gain, lots of heat loss. And they're, they're hurting the envelope because of the huge amount of thermal conductivity in the frames. If they're aluminum, the cheap ones. Um, and they're, they're condensating and they're creating mold issues, so. Spend more money on your windows in the outlay and uh, make them smaller.
Matt: You are just in Europe.
Jess: Yes.
Matt: And so the difference in windows is vastly different. What? That's, well, what we see in our space are the same. But what we see as a broader view in the the Australian construction world and the Australian homes, they're completely different. Do you wanna just talk about that?
Jess: Yeah. Actually, when I went over to Europe, I wasn't thinking about construction window. I wasn't thinking about how different the houses were gonna be. I was just thinking about going on the school holiday. But as soon as I got there, it was immediately obvious to me how different their construction is, their [00:02:00] doors and their windows are what we consider high performance.
And of course. They get snow where I was. Yeah. And so that's a necessary thing, but uh, we also get very, very cold here. Yeah. And that seems to just slip people's minds when they're designing their homes. It's
Hamish: bizarre, isn't it? You are in town right now because you, uh. Thank you by the way, uh, a part of our SBA event today, and we're talking about, um, health and wellbeing in buildings, and a big part of what you do is about trying to make that environment inside as healthy as possible.
So we touched on mold. Can you tell us a bit about mold? And why it's bad.
Jess: 25 to 30% of the population has a high mold sensitivity. Yep. And those people cannot be in moldy buildings. They have severe health impacts, such as, uh, chronic fatigue is one of the really big ones. And I think there are a lot of, a lot of people to sort of run around the country with all these severe, uh, health.
Ailments that they don't [00:03:00] actually connect with their living environment. You know, the health professionals in Australia don't make that connection for them. And so there's a, there's a huge information gap there. Stats are that 40% of Australian homes, new Australian homes and apartments have got mold in them.
In my experience, it's. Probably a hundred percent because mold, '
Hamish: cause you, you hit, you hit the, you said something just there like mold is everywhere. So what is the mold that's actually making us sick?
Jess: The, there's toxins in the mold. So, I mean, I couldn't give you the exact ins and outs of how it works.
Yeah. There's a biotoxin in mold that, uh, is, is airborne. Um, and you can disturb it, you know, if you've got mold going on your curtains, for example. Yeah. Like you've got a window. That condensates over and over again and the curtains get damp and they grow mold over time. Yeah. When you disturb those curtains, uh, the mold spores, there's a plume of mold spores that you, and we breathe it in, can't see, and you breathe it in.
Yeah. It affects, uh, your lungs and it affects your immune system.
Matt: Yeah. And I think that's pretty high cases. Um, there's a study from South Australia, I'm [00:04:00] pretty sure from memory it was 50% of Australian homes have mold that is directly linked to childhood asthma.
Jess: Yeah. Asthma's huge. Asthma's huge. Um, those stats, I'm again not a hundred percent sure of, but um, respiratory issues are massive and, you know, in connection to mold.
Hamish: Go back to this chronic fatigue thing for a second. Mm-hmm. Because that's interesting. Kind of my mind goes to, um, glandular fever when I think about chronic fatigue. Did you have it when you were a kid? I had glandular fever when I was a kid. Yeah. Kissing too
Matt: many
Hamish: girls. I tell you what, when I got glandular fever, is that why you wanted to bring this up?
When I got G? No, no. Just a gloat. No, no, no. When I got glandular fever, I definitely was not kissing girls. Um, if you had to see me at that age, I, you probably know why. Um, but yeah, look, it's interesting because like we kind of put chronic fatigue in like a little bucket over here and, and don't generally relate it to maybe where we live.
Or sleep or spend 80 to 90% of our time. So like, is, are there actually studies that sort of make that link between mold and chronic fatigue?
Jess: There are,
Hamish: yeah. So
Jess: there's, [00:05:00] um, there's a guy in the US called Richie Shoemaker. Yeah. And he is sort of the, the serve. Guy. He's the doctor. Oh, okay. Yep. SIRS is chronic inflammatory response syndrome, and that is an umbrella term for the multitude of illnesses that come from mold exposure.
So it's basically an inflammatory response in the body. So
Hamish: is sirs, SERC,
Jess: chronic inflammatory response syndrome. So it's, it encompasses so many different things. Um, I have a slide in one of my presentations that lists all of them. There's, there must be. From 30 or 40 different sort of ailments that are directly related to mold exposure, that sort of is not commonly known.
Hamish: Alright, so we agree. Mold equals bad. We don't want mold around buildings. I mean,
Jess: generally, even if you're not susceptible to mold, if you're not mold sensitive, you kind of don't want it anyway 'cause it's. It's, it's unsightly and the, is it just
Matt: getting some white king and bleaching it off?
Jess: No bleach, definitely not.
It will kill the surface mold and it [00:06:00] will make the color go away. Um, but it doesn't kill the roots of the mold. So, and the only way to
Matt: get rid of it is to remove, remove it. Yeah. Yeah. And if that's where I wanted to get at, because I think people have this idea where bit of paint, bit of white king, it's all good, it's all gone, but it's, what you can't see this is, is actually what is hurting you.
Jess: Yeah. And you can kill mold, but it's, all it needs is a little bit of dampness and moisture and it'll come straight back.
Matt: Yeah. Yeah. So now you, you were talking about, uh, doctors and the medicine side of things. Why isn't it recognized by doctors and medicine as an issue?
Jess: There was a research paper done in 2018, uh, the sort of, I forget the name of it, research into bio and illness in Australia.
Um, and it was done in Victoria, I think in this state.
Matt: Yeah,
Jess: I've read parts of it and there were so many. Patients and health practitioners who came to the front who ca put their hand forward and said, this is my experience and blah, blah, blah. And essentially the Australian medical response was, we're just gonna put that over here, umbrella term of things that [00:07:00] we don't understand.
Um, right. And it was sort of dismissed by and large by that study from the, the parts of that study that I have read. Which is pretty frustrating for those people who have to live in tents in their back garden because they can no longer be inside their houses.
Hamish: Do you know what is frustrating that the NCC, which is I guess what dictates how we build here in Australia.
Has made that connection. Now let's put it in the 2022, um, NCC updates, but they've quite nicely handball that responsibility onto the builder.
Jess: Yeah. It's if, if anyone actually pulled that clause out of the code and said, I'm gonna sue you because my house is moldy. It's actually very vague as to. Where that buck actually stops, you know, because there's a whole raft of people who have an input in Absolutely.
How that works.
Hamish: Totally
Jess: down to, you know, to the, the energy assessor, the architect, the builder, the client, you know? Yeah.
Hamish: That's really interesting actually, that you talk about the client because say I could build a passive house. Mm-hmm. Right? And the [00:08:00] clients could turn their HIV off and they could
Jess: mm-hmm.
Hamish: Um, close all their windows and they could actually create an environment where there's mold.
Jess: Yeah, they could.
Hamish: So, you know, we build these homes where we think that the clients are gonna thrive in this environment, but they could be a one star client and, um, create this really toxic environment and they're gonna get sick.
So where does the buck stop? That's really, it's a really interesting point that you make there.
Jess: Yeah. The co, the clause and the code requires. Some, some further development and it requires some, you know, interpretation and, and someone to actually clarify. 'cause at the moment it's, it's in there and it's sort of.
Waking people up and it's making people think. But it's still very vague.
Hamish: It is very vague. And I think without the the, and this is where we think that there's shortcomings in the NCC, there might be just one or two, just one. Maybe just a couple. One or two. One or two. Because you know, we wanna stop mold that's coming from Mr.
Switzerland too. But then there's no, but then there's no requirement for mechanical [00:09:00] ventilation, but we want to make sure the. Buildings are really well ventilated, and then we're gonna put a class four wrap over the entire building. Are we not creating an environment that's probably susceptible to mold if we're not then ventilating properly?
Jess: Yes. So in the 2025 code, um, are you talking about cavity ventilation?
Hamish: Are you talking about, I'm just talking about dis ventilation in the house.
Jess: I mean the, the code currently doesn't, code currently
Matt: says that you just need to be able to open your windows and doors. Yes. And they need to be built in, designed in a way to.
Potentially prevent water ingress. Yeah. I'm pretty sure that's how it's written. It's like it has to have the ability to stop
Hamish: water. Anyway, we, we we're, I'm gonna put my switch on the hat back on again because Rashid can, the NCC, but I think that that what, what I want talk about is mold is bad, and what is it that you do in your daily life.
Mm-hmm. That helps educate people or train people on how to create a really healthy living environment.
Jess: Uh, majority of that comes down to, uh, sort of the management of heat, air, and [00:10:00] moisture, um, and how that is done on site. So I work primarily with builders and clients. I'm finding that the drive from clients is quite strong.
Clients will go to a builder such as. Yourselves. And then sometimes that that price point is out of their budget, they'll go to a, a builder who gives them a lower price. Yeah. And then they'll circle back to me and they'll say, Hey Jess, can you help me do all that cool stuff? But with this builder, my first question is, does the builder wanna know about this?
Yeah. And so that's a large part of my job, is going on site, talking to builders, getting on the phone. Looking at plans like working out how far I can push it with each individual
Matt: builder. Yeah. How do you refer to yourself? Are you a building scientist? Building biologist?
Jess: Building science consultant is sort of what I've knuckled it down to because when someone asks me what I do, I'm like.
I don't know how to tell. And you're going down a journey
Matt: of this building, biologists. Yeah. And do you wanna just tell us what that is?
Jess: Yeah. So building biology is basically just a study of the home and the, the, the, how it impacts your health. There's a, a course that I'm doing through the Australian [00:11:00] College of Environmental Studies with a lady named Nicole sma.
She's fabulous.
Hamish: Was she on your podcast?
Jess: She was,
Hamish: yeah. I listened. She was on that. Yeah. Yeah, yeah.
Jess: Yeah. So. Three. Three, I think. Yeah, yeah, yeah.
Hamish: Yep.
Jess: So she is the, the sort of director of the college. Um, she is sort of leading that building biology industry in Australia and has been doing for some time. I mean, building biology is the study of the home and the health impacts that it has.
So the subjects of things like uh, or mold is obviously the first one. Yeah, there's two very large mold subjects. Then there's, uh, you know, low to materials. There's, uh, water, like subjects on water, um, FNG shui. Yeah, because it also comes down to. The soul. Well,
Matt: this, this where I wellbeing, this is where I wanna get at because I feel like building biology has this woowoo hippie, I'm gonna do a rain dance out in an open field view.
I don't think so. I, I I reckon that's a general, what people would feel. I think it's Matt's general. No, but I think that's what the industry, a lot of people would feel it's that way. But like for us, this is [00:12:00] just how you should build
Jess: this is, this is bread and butter stuff. Yeah. Like the mold stuff is what attracted me to building biology.
Yeah. Um, Feng shui is kind of like a cool. A addition because how you feel in a space affects your wellbeing.
Hamish: Yeah, a hundred percent. I mean, I, I listened to a podcast the other day. I can't remember whose it was, and I had a f couple believe Fway expert on it, and I'm like, it actually sounds pretty fucking cool.
Yeah. I just wanna get back to your, your mentor. What was her name again? Nicole Gilman. Nicole. Okay. Because I was listening to your podcast. And for those who, dunno, what's your podcast called?
Jess: The Building Psychology
Hamish: Party. Thank you. Play plug. Um, she had a really interesting story about pregnancy. Yes. And like, you know, as someone who's, who's gone through stuff with pregnancy and had babies and all that kind of stuff, like it's a pretty traumatic place to be in.
And listening to her story, about how many miscarriages does she have? 10. Like 10, 10.
Jess: And now she's got three children. Happily. 10.
Hamish: Yeah. 10 [00:13:00] miscarriages. Yeah. 10. Yeah. But what was really interesting about her and I, and I, and I always kind of take these kinds of stories 'cause they're quite anecdotal, right?
Mm-hmm. Now, however, the evidence from her experience, she moved rooms.
Jess: Yeah. So she attributed her miscarriages to, uh, osteopathic stress and EMFs,
Hamish: which is pretty crazy right now. I am gonna be the first person to say. I am not convinced on EMFs just yet. Yeah, right. And I think that's fine. I'm on the
Jess: fence too.
Yeah.
Hamish: I'm gonna say I'm on the fence, right? Mm-hmm. I know Matt, I
Matt: think that I, I, I think that they are a load of potential crap, but I also think that there is, you shouldn't be living next to a 5G tower or putting your modem or your solar invert at the back of your bedhead. So I, whilst I think a lot of it is a load of crap, I also think a lot of it is also relevant.
I think the issue is people just jump to the whole end of the other scale and focus on things like this, but EMFs exist. Yeah, they do, but there's no, they exist. There's no study that has actually been independently [00:14:00] taken out or has been peer reviewed that shows there an issue within the Australian household.
Hamish: I've googled this a couple of times. If you go onto the WHO website, the World Health Organization, their opinion is that in some circumstances with some immunocompromised people, maybe sometimes pregnant people can be impacted. By EMS. There's one
Matt: study on pregnant women in a household around, uh, cooktops.
That's it, but only between certain periods of a certain trimester. Yeah.
Jess: I think Nicole's PhD was on EMS.
Matt: Yeah.
Jess: So I ha I would be interested to read that, but it wasn't, yeah.
Hamish: Like it. For people who haven't listened to that podcast episode with Nicole, it is worthwhile going back and listening to it. 'cause it really is an interesting thing just to make you think.
Yeah. If that's all it does, then I think it's. Doing the
Matt: right
Hamish: thing. That sort of being aware of
Matt: just the guru stuff, like I feel a lot of it is. Pushed so far down the other end where it feels like you've gotta wear a tinfoil heart to be part of that conversation. And I think sometimes, like simple shit, [00:15:00] we always say, simple shit works.
We've gotta bring it back to the basics and educate people around, Hey, don't put the solar inverter at the back of a bad head. And just start with that. Yeah. Like you wean people onto the conversation then make people, you can't alienate people. Yeah. And make them feel stupid or, yeah. Yeah. Make, make people feel scared and use fear-mongering to then
Hamish: push that agenda.
And we're talking about cost. And cost of building. And you know, some people might not be able to afford to build a passive house or the homes that Matt and I build. What are the three things, and I'm just randomly picking three. What are the three things that you would say are absolute like must haves in any building
Jess: load or test?
Hamish: Yes. Okay, so air tightness.
Jess: Yeah. So what quantifying your air tightness. Quantify air. Air tightness. Understand how to ventilate it appropriately. Oh yes. I love
Hamish: that.
Jess: So you don't necessarily have to build airtight, but you just have to understand where your air tightness is at in order to make it a healthy place.
Hamish: And we're talking about like a 800 to a thousand exercise here, correct? Yeah. Okay. So quantifying air tightness. Yep. We [00:16:00] should be mandatory in the NC. Let's just put that like how that is not, but let's also point out the NCD does say that we should be building to the, it says in the NCC that all Australian homes should be no more than 10 air changes optional.
Is that optional?
Matt: Yes. How can you have something that you can do it, but it's also like you have to do it, its optional. It's a
Jess: performance solution. So you can, you can make sure that your windows are kind of sealed or able to be sealed. Okay. I thought, I thought, or you can make sure that your exhaust fans are sealed, are able to be sealed, or you can do a bullet on test to, to comply with the building ceiling section of the building code.
So it's not, it's not compulsory. I,
Hamish: okay. So that's number one. Quantifying air tightness.
Jess: Yes. Quantify your air tightness so you can understand what you're dealing with because it's invisible.
Hamish: Yeah.
Jess: The second thing is thermal bridging. So if you have any steel, please, please inate it externally. Please, please.
So, quantifying air
Hamish: tightness, thermal bridges, managing thermal bridges.
Jess: Yep. Uh, including, I put window frames correct in that. I was gonna
Matt: say, but you've said three and then you haven't put windows, which is the most important. I was like, please, please put windows in, windows in that we're
Jess: bridging. [00:17:00]
Matt: Yeah.
Jess: Um, so, you know, upgrade your windows. Your window frames as much as you can. And the third one, uh, non non-negotiable would be check your insulation when it's being installed. Make sure that that is done properly, because if you have big gaps, then. You have them bridges and you have heat loss.
Hamish: Now I was probably a little bit unfair then just saying pick three because, oh, there's, there's, there's, there's lots of them.
There is, but like, I feel that like you're just talking about quantifying air tightness. Because if we kind of use these as subheadings, quantifying air tightness then allows you to understand what ventilation strategy you're gonna even be using. So that could be fans, it could be opening windows, it could be ducted, rangehood, it could be this could be that, or it could be on the other end, a full centralized.
Ventilation system if you're really airtight. Yeah. Thermal bridges, if we look at that as a subheading, oh fuck, it covers so many things. Yeah, it does. You know, timbers and steel projecting out through windows, obviously covers how, how
Jess: the building is framed so that you don't have big
Hamish: correct voids. [00:18:00] Yep.
And then checking your insulation, fuck me. Why? I don't know that that is not something that has, that shouldn't be checked. Mm-hmm.
Matt: Like it's really easy and it's actually easier. It's also a, but very difficult because I think the issue is people walk around with a thermal image and go, yeah, it's all good, but is the heat differential from inside to outside?
Yeah. Actually showing you what's happening. Yeah. Understand what you're looking at. You actually understand what you're looking at too. So,
Hamish: but if you think, if you think of the, the, the investment that you're making in insulation, it's such a small percentage of the overall build cost, but it's probably, I would argue one of the most important Yeah.
Things. And one code,
Matt: one line in the NCC to change can change both. Two of those points is like a building must be verified to, to meet its performance goal. Oh yeah. Yeah. Like that cancels our that That ticks off the installation. Installation. And that ticks off the air tightness. So
Hamish: your three takeaways, quantifying air tightness, thermal bridges, and checking installation.
Correct. Now you have your own podcast. I do. As we talked about before. So my final question to you is, when are we coming on?
Jess: Let's book it in
Hamish: because I feel like, um, a lot of the things [00:19:00] that we're talking about or we talk about when you talk about, are super relevant to both of our audiences. Yeah. So, you know, for, for everyone who's listening to this, who listening, who loves the mind, build a podcast, um, definitely jump on and.
Building psychology. Mm-hmm. Podcast. Yep. How many eps are you up to now?
Jess: Uh, just about to release episode seven on Monday. Boom.
Hamish: And I understand that that's all done by you.
Jess: It, yeah. Yeah.
Hamish: All right. Me,
Jess: myself, and I
Hamish: Now, Jackson, I'm gonna look at the camera here. I feel that there should be a small investment from Climb Shore and Enduro Builders that is gonna be invested in Jess's podcast.
So Jess, you're welcome. Thanks for coming on.
Jess: No worries. Thanks for having me.
Hamish: Thank you.