How To Biohack The Ultimate Healthy Home: Part 2
29 Jan 2026 · 41 min
Stephanie Horowitz from ZeroEnergy walks through retrofitting homes for health: circadian lighting with clerestory windows and automated shades, airtight envelopes with HEPA filtration, testing for radon and mold, and choosing low-VOC finishes. Energy audits and blower-door testing identify where to start.
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Welcome to the BenGreenfieldFitness.com podcast. We provide you with free exercise, nutrition, weight loss, triathlon and wellness advice from the top fitness experts in the nation. So whether you're an Ironman triathlete or you're just trying to shed a few pounds, get ready for non run of the mill cutting edge content from BenGreenfieldFitness.com.
Hey folks, it's Ben Greenfield. And if you've been listening to the podcast recently, you know that we are on a serious kick about making your home a healthier place to be. Now I'm getting experts on to actually talk to you about biohacking your home or hacking your home or basically taking into consideration everything that's around you, from your air to your lighting to your cleaning supplies to just like all the different ways that you can achieve big health and performance physical and mental wins in the place where you spend the majority of your life. And today's guest is Stephanie Horowitz from zeroenergy.com Now Zero Energy is a green architecture and design firm and they're real experts in not only creating kind of net zero energy homes, as the name would imply, but also at making homes a healthy place to be, not only in terms of reduction in energy use and carbon footprint, but also the type of things that are around you when it comes to your health and your body. Now, Stephanie manages a lot of the projects that Zero Energy does, and she's been on a TEDx presentation before. And I'll put the video for her excellent TEDx presentation in the show notes for this podcast as well over@BenGreenfieldFitness.com but she was actually awarded Boston Magazine's Best of Boston for the best green architect. She's received a ton of awards for all the work that she's done, particularly in the area of green architecture. She graduated Cornell University School of Architecture and she's a real expert when it comes to this stuff, so we're certainly privileged to have her on. And Stephanie, thanks for coming on the call today.
Thanks for having me, Ben.
So, Stephanie, let's jump right in to what happens to folks in terms of their physical manifestations of living in an unhealthy home. Are there specific signs that you see pop up over and over again in terms of physical signs that someone's house might be affecting their health?
Well, you know, your home is affecting your health. Sometimes there are really obvious symptoms like an allergic reaction, coughing, sneezing, congestion. But it could be something that's much more subtle that takes place over Time exposure to toxins that start to influence the development of your children or that keep you from reaching optimal health and performance.
So do you notice things like brain fog or poor sleep or specific kind of, like, things that you can really put your finger on when it comes to things that your home might be doing to you?
Yeah, I think that for everyone, it's really different. And sometimes there is something that's really easy to point to, like you don't sleep well when you're at your house, relative to if you're staying at a hotel. So it could be degradation of your sleep quality that you start to notice, or it could be something that really kind of goes undetected. But whatever it is, your home, the place you really spend the most time, has a really big influence on your health, whether there's something that's really easy to point to or not.
So let's talk about some of the things in a home that could affect your health or your sleep or the way that your brain functions during the day. And I just want to jump into the nitty gritty, if that's cool.
Yeah, absolutely.
Okay, let's talk about lighting. I'm interested in hearing how a home's lighting can affect physical health and also if you have specific lighting strategies that you recommend for people.
Yeah, absolutely. Well, you know, Ben, I'm going to defer to you on some of the great health benefits of daylighting. But, you know, we have a lot of great strategies for bringing daylight into a home, which is really the best way to light it. Some examples, using high windows, transom, or clerestory windows are a great way to bring light deep into a space, looking for opportunities for borrowed light. So using an interior window to transfer light from an exterior space to an interior space, using a light tube can be a great way to bring some natural light into a hallway or a dark room.
Now, what exactly is a borrowed light and a light tube? What do those look like, or how do they work?
Well, I mean, I'd say borrowed light is really just a strategy, but you can use an interior window, which is exactly what it sounds like, to bring light from one area into another. We had a client who really wanted natural light in the bathroom so that she could use it while she was putting on makeup. The kind of design worked out that we didn't have a window into the bathroom, but what we were able to do was to put in an interior window that sort of linked up with a skylight or a clerestory window. And that allowed us to bring that Natural light into the bathroom, where otherwise it wouldn't have had any, you know, we wouldn't have had any natural light there.
Right. And what was this light tube that you were talking about?
Yeah, light tube.
So.
It'S literally, it's a tube that has a lens that goes through the roof and it funnels light into an interior space. It's got a really kind of reflective lining on it that helps the light to bounce and transfer. And it's something that you can plan for if you're doing new construction. And it's also something that can be added after the fact as part of a renovation or retrofit.
Huh. That's really cool. I'd never heard of something like that before. Are there other ways that you find that people can set up their lighting scenarios? Like, do you have different types of lighting that you use in different areas of the house, for example?
Well, I think you talked about lighting scenarios, and I think that is really important. And when we work with our clients, we listen to what their sort of experience is with natural light and what their preferences are. I think that designing proper blackout shades in a bedroom is really important for getting great sleep. And one of the things that can be really great is to tie the shades to an automation system so that you can have the shades open in the morning to wake you up with natural light. And that's something that, when we're doing these things already, when we're planning for the blackout shades, when the client has an interest in some sort of automation, we can tie that into the lighting in that particular way.
Interesting. Does that. And I don't know if this is a question you know the answer to, but when you automate something like that, you know, those blackout shades are obviously going to be pretty close to the bed where you're sleeping. And for example, I know that a lot of our more savvy listeners are trying to reduce electromagnetic frequency exposure while they're sleeping.
Yep.
So if you've got, like. If you've got, like some kind of an electrical hookup to automatically make your blackout shades open, does that affect your EMF exposure while you're sleeping?
It can. There are a number of different ways that the shades can talk to the automation system. So it can be hardwired, it can be wireless, depending on the technology. And that's something I would definitely recommend looking at if you're kind of paying close attention to ems. We have a lot of clients who really look to design their bedroom as sort of an oasis where we'll keep out all Things electrical, and look at even things like kill switches to make sure that they can really kind of keep the EMF out of the area where they're sleeping. So I think it just depends on what's important to you.
So you can basically just get, like. What would be the technical term if someone already lives in an existing home and wants to look into those kind of blackout shades that are automated? Are there brands or anything like that that exist out there?
Yeah. So there's the shade, and then sometimes the motor is made by a third party, But Lutron makes an automated shade. Hunter Douglas has some options as well.
Gotcha. Cool. And those basically, for those of you listening in, you know, when we're talking about natural lighting and blackout shades, it's essentially a matter of ensuring that your home is allowing your circadian rhythm to operate in the way that it would in kind of an ancestral way, meaning that you're getting more blue light, natural sun exposure during the day, and then you're limiting artificial light and light exposure in general during the night. I mean, it's simple, but I think a lot of people don't think about building these kind of circadian rhythm concepts into their home when it comes to lighting. So it's interesting stuff. Now, what about Stephanie? I wanted to ask you about airflow in a house. And not only just like, if someone should have air filters installed in their home, but if there's ways that you can design a home or set up a home so that the air you're breathing all day long is actually healthy.
Absolutely. You know, when we talk about air quality, we really need to think about the house as a system. So if you think about the way your body works, you've got one system that introduces fresh air and expels contaminated air. It all comes in through your nose and your mouth and then passes through your lungs. There's no uncontrolled air that seeps through your feet or your armpits. Your house should be no different. So when we design our homes, we detail an airtight enclosure or building envelope. And then we introduce mechanical ventilation, a system that brings in fresh air and exhausts the old stale air in a controlled manner, just like your body. Now, this airtight detailing has a lot of added benefits. It's going to significantly reduce the moisture that gets into your building envelope. And moisture, of course, can lead to rot and mold and things that you really don't want embedded in the structure of your home. It's also going to improve thermal comfort, so reducing drafts, controlling humid. Once we think about the house functioning as a proper system in this predictable and controlled way, we can then start to look at not just filtering that air, but also limiting and controlling the toxins and contaminants that we bring into the home.
Now, what kind of filters do you recommend for people's homes?
A HEPA filter is, is really a great place to start if you have an existing system that has one of those disposable filters. I would say the most important thing is to make sure that you change it regularly. So every two to three months, so many people will don't even realize that there's a filter to change in the first place. And that's a great place to start is just make sure you change it.
Now in a new construction. I know that there's a lot of issues when people move into a new home with a lot of these gases and kind of toxins circulating in the air. Do you think people should wait a certain period of time before moving into a new home or just have these type of air filtration systems installed?
Yeah. In a new home, these products and materials that off gas, they typically off gas the most when they're first installed. So flushing out the home, running your ventilation system on exhaust, only, giving the house some time to literally air out can really help flush these toxins out of the home before you move in.
Gotcha. Now, what about people who live in homes for which they may not be a new construction, but they're concerned about things like mold toxins? You know, we hear about a lot of these things causing lifelong allergy or autoimmune issues in people. Do you have ways that you found. I mean, I know you guys specialize in new construction, but for you as an architect, have you run into ways that people can kind of mitigate some of the effects of, you know, an area of the house that's already been exposed to moisture that might already have molded?
I mean, I think you've got to start with what's there. So trust your nose. If it smells like chemicals or it smells like mold and mildew, you probably have a problem or it's something that's not good for you, and you can start to look at options for remediation. A basement is a really common area where we see a lot of mold and mildew. You know, you want to start with kind of getting rid of what's there and then repairing the broken system. So do you have, you know, water leakage? Is the basement not properly insulated? What is, you know, what's causing that mold? And mildew so that you can fix it so that it doesn't come back.
And how do you. Do you have recommendations for ways to get rid of that mold in the first place?
You know, there are definitely some specialists that deal with mold remediation. I think it kind of depends on where it is. Just getting rid of the material is probably the most effective, but isn't always practical. So for example, like if you move into a house that's got kind of a mildew based, mildew smelling basement and it's got carpeting, you just need to remove the carpeting. It's going to be the first step to getting rid of the problem. If you've got mold growing on the joists in your home, that's a little bit more of an issue because you can't just take them out.
Gotcha. Now you mentioned carpet there. I know that carpet can tend to off gas a little bit. Can you talk a bit about what that is and what we might be able to do about that when it comes to carpet?
Well, let's come back to off gassing and just talk about carpet. Carpet is like the sponge in your kitchen sink. When you move into a house or an apartment, you're certainly not going to reuse the sponge that the old tenant left behind. You're going to get a new one and you're going to replace it frequently. So wall to wall carpeting is kind of like the dirty sponge that you can't replace. It soaks up dirt, allergens, dander, dust, and it's just not possible to clean really well. So when it comes to flooring, you really want to stick to hard surfaces like wood and then add area rugs for warmth. They're much easier to clean and you can replace them.
Gotcha. So there's pretty much no carpet out there that you would recommend.
No, that's not true because, I mean, I think that there's certainly a place for area rugs. You want to look for carpet and any sort of carpet accessories that meet the Carpet and Rug Institute's Green Label plus program.
Okay, that's called the Green Label Plus Program.
Yep.
Okay. Is there a website that folks could go to to see that?
Yeah. So CRI is the acronym for the Carpet and Rug Institute.
Okay, gotcha.
And that'll lead you right to their certification programs. But yeah, you want to look for something that meets or exceeds the standards of the Green Label plus program.
Okay, I'll put a link in the show notes for people over to that.
Resource and you know, sorry, just you know, another kind of recommendation of what to look for when you are looking for carpet. Carpet tiles can be another great option. They're economical and you can replace the individual tiles if they get, you know, dirty or stained. Floor F L O R is a company that, you know, makes a really wide range of products and most of their carpet tiles have that green label plus certification that I mentioned.
Nice, nice. They're the floor modular carpet tiles.
Yep, yep. They're about, you know, they range between, you know, five and ten dollars a square foot. You can, you know, use them as an area rug or you know, you can even install them kind of wall to wall if that's, you know, really what you're looking for in a bedroom, for example.
Cool, cool, great tip. I'll check those out. Now, in terms of other issues from flooring to also walls, cabinets, finishes, stuff like that, I know that when it comes to finishers and varnishes and paints that a lot of this can affect health. What should people be looking for when it comes to non toxic solutions for a new home or things that they can incorporate in an existing home? When it comes to what we're putting on the surface of some of these things?
Yeah. If you've learned to read and scrutinize food labels, you should really do the same with the materials and the finishes that you're bringing into your home or hire someone to help you. An MSDS or a material safety data sheet is kind of like the bad nutrition facts for any given material. And that's the first place to sort of start reading. You can also rely on a third party green certification like the green Label plus program that I mentioned to kind of help you screen the products that you're using. But you know, two kind of easy components to screen for are volatile organic compounds, VOCs and formaldehyde. You want to look for products and finishes that have either no VOCs or low VOCs which are typically defined as having less than 50 grams per liter. And that's something that, that MSDS is going to tell you.
That's called the msds.
Msds? Yeah. Basically any kind of product or finish that you can buy or specify is going to have this MSDS that tells you about all the kind of nasty stuff that's in the product.
Is there a website or a resource that people could go to that would automatically give them that information or give them a safe list?
It's going to be on the manufacturer's website and it's usually, it's pretty easy to find the link. Sometimes it's in the technical documents section. But each manufacturer is going to offer that MSDS on their website.
Okay. Okay, gotcha. And so, once again, the numbers that you said that we should look for when we're looking at the MSDS for a varnish or a finishing would be what?
When you're looking at the VOCs, you want to look for something that has no VOCs or that has less than 50 grams per liter, and it'll be listed as GL.
Okay, perfect. Perfect. Cool. Now, as far as things that you should be concerned about in addition to, like off gassing or, you know, the volatile organic compounds coming off of a finish, if you're moving into a new home that was recently built, are there specific things that you should be concerned about in addition to the things that we've already discussed?
Yeah, I mean, I think that any home, new or old, has. There are a lot of things you can think about and a lot of things that you can do. Take off your shoes, especially if you have kids, you track in all kinds of stuff. Dirt, allergens, pesticides from your neighbor's lawn or the park, gasoline, literally the crap you stepped in. All things that you don't want in your house, and you certainly don't want your kids playing in it. Again, sort of a user behavior. Take a look at your cleaning products. You may be introducing chemicals and toxins without knowing it. The Environmental Working Group is a great resource for evaluating cleaning products, and I think their website is ewg.org the book Organic Housekeeping or Greenhouse Keeping by Ellen Sandbach is also a great resource.
Okay, great. And that's Ellen Sandbach who wrote that.
Yep.
Okay, awesome. I'll put a link to that in the show. Notes for folks. Now, what about if you are moving into an older home or you live in an older home? We talked about mold and screening for mold or kind of, kind of being sure to remove moisture from areas of your home that might have moisture. Are there other things that you should look for if you already live in an old home or apartment?
You know, I think that you can look at some testing so, you know, making sure that you don't have, like radon in your home, for example, and, you know, making sure that you have carbon monoxide detectors. Like really, you know, kind of worst case scenario. Worst case scenario things. There are some meters that will actually look at VOC levels in your home that are kind of neat. And we've just sort of started, you know, using those as a diagnostic tool both in new homes and old homes. To kind of detect if you have a problem. Attached garages are a really big one. It can be a huge source of contamination if you don't have a proper air seal between your home and your garage. And that's something that you really want to fix whether your home is new or old, because it's going to be an ongoing problem.
Interesting. I hadn't even thought about that. So the issue with the attached garage, is it mostly the fumes from a car or are there other issues?
You know, it's the fumes from a car, it's the paint that you're storing out there. You know, it's all the things that you purposefully keep in your garage and not in your home. And the problem is that when the two of them are attached, you might actually be getting those toxins and contaminants kind of coming into, you know, coming into your house without knowing it.
Interesting. Gotcha. Okay, cool. Now, there's a PDF that is over@zeroenergy.com It's a Healthy House PDF and I'll be sure to link to it in the show notes for folks who are interested in checking it out. But the title of that is Building a Healthy House, and it goes into some key concepts for building a healthy home or some of the things that should be taken into consideration for a new home. Are there aspects of that article that we haven't really gotten into that you want to highlight or discuss or any tips you want to give to people from that?
Well, I'm not sure how much we talked about this in that article, but I think you've really got to think about does your home fit your lifestyle? We've talked about things to avoid and control, but how does design facilitate healthy living? And there are a bunch of things to think about. Maybe your workout room does not belong in the basement. A yoga studio with great light and views can double as a study or a guest room in your kitchen. If you make a kale shake every morning, is there a proper place for your blender? That's something that you can think about when you're designing a home. You know, thinking about all those kind of countertop appliances that you might use really regularly but don't want to look at. So a lot of times we'll either rely on a pantry or designing in. It's called an appliance garage, which is kind of like a great place to store those countertop appliances that you use frequently but. But don't really want to look at.
Gotcha. Okay. Now you also talk about ultra Low energy lifestyle like that was the name of your TEDx talk. What does that mean? Ultra low energy lifestyle?
You know, when it comes to overall health and environment, and you know, I'm even talking about big picture here. We really think that energy is one of the most important things. And energy use in your home is sort of an issue that we've really chosen to tackle and focus on as professionals. So when we look at energy use in the US a significant portion of of energy is actually being used and consumed in our homes, and specifically in our buildings, but also in our homes. And by designing greener, more energy efficient homes as well as retrofitting the ones that we have, we can have a really significant impact on energy use that has some great global benefits, some environmental benefits, and it also can really help your wallet keep your operational costs low. So we think that kind of controlling energy use really starts with the home that you design or the home that you retrofit and live in. We look at, you know, we talked about that kind of airtight enclosure, designing a predictable system to control your heating and your cooling, making sure that the things inside your house are really efficient. Your heating and cooling system, your ventilation system, the other things that use energy, like your appliances and lighting. And then the last kind of piece of that energy equation, of course, is the responsible user. So we like to talk about zero energy homes, but say that there's not really such thing as a zero energy home, but there's a zero energy user because that's that last component that as an architect, we don't really control.
Hmm, interesting. You know, I think a lot of this stuff people don't really think about, I mean, not just like using formaldehyde free, you know, wood products or zero voc paints, but also the monetary aspects of the energy loss, you know, and I don't know if that's something that you've done much work with as far as things that people can do that go above and beyond what we'd normally use for energy. And what I mean by that is the utilization of things like solar panels or wind or alternate ways to actually make your home go. Do you guys do much when it comes to giving people solutions for energy sources that go above and beyond the local utility?
Yeah, absolutely. We definitely start with controlling the things that use energy, the things in the house itself and the things inside it. But after we sort of squeeze out all of the possible energy out of the systems and the house itself, we then look to offset that really low energy use with renewable technologies. So solar panels Are really a great one. They can go right up on your roof. If you've got a larger property, they can go in a field and actually offset the energy use that your home uses. And in some cases we're actually getting the homes to be net positive so they're producing more energy than they use, which just completely really wipes out your energy bills and can even start to give you this excess energy to power an electric vehicle, for example.
Wow, that's amazing. So for people who live in an area that does not have adequate sunlight exposure, Are you typically putting those on a roof?
Yeah. And the solar panels, the technology, it really works well all across the country. Whether you're in upstate New York or in sunny California. The panels. Panels work well in all situations. Sometimes there's a lot of shading on a site where it becomes infeasible, but they can really be used anywhere. And putting them up on a roof is usually going to be your best bet in terms of getting access to to unobstructed south facing sun. And it also can be a really kind of economical installation in that you're not paying extra for a ground mount system. It's just sort of clipping the panels to the roof that you already have.
Now what about people who live in windy areas? Are there ways that we can use the wind, I mean, home friendly type of installations?
Yeah, I would say that using wind at the residential scale is a little bit more problematic just because there are some, there are local regulations that make it more difficult to incorporate the wind turbines. And there are some smaller products, vertical axis turbines that people are using in more kind of rural or sometimes residential settings. But in general, I think that the financial aspects of investing in PV photovoltaic panels, the solar panels is really much stronger in most parts of the country. They work whenever it's sunny and that happens every single day. And those are just feeding, it's really reliable.
Are those primarily feeding into like a battery storage or do those feed directly into the home?
Battery storage is usually an add on that. You know, it's a great thing if you really want that backup power. But batteries are expensive and they have a limited service life. So you might have to replace them after seven or eight years, let's say. I think the technology is improving, But I would say that only a small number of our clients choose to install batteries in combination with the solar panels.
Okay, interesting. So are there other aspects of building a zero energy home or a green, you know, healthy home that we haven't got into that you think would be big wins for the listeners.
So, you know, I think that if you're working with an architect, which obviously I think is pretty important, it's really important to retain them for a service that we call construction administration. And the reason being is that you can hire someone to design the greatest, greenest, healthiest home with the most non toxic products and the best building envelope ever. But it's really not worth anything to you if it's just on paper. So the construction administration service is where your architect will observe construction. They'll be a resource for the contractor and they really ensure that what you, you know, you get what you paid for. Basically it's, you know, it's kind of like a personal training service. Right. You can, you know, you can, you can get the information, but you really want to have your architect be your advocate, be your eyes and ears to kind of walk you through the part that matters most, which is going to be the construction or the renovation process.
Now for people who aren't building a new home, are there services that folks can take advantage of where someone will come into their existing home and act as like a consultant to do anything from get rid of mold to improve the energy availability to making an existing home more green? Like are you aware of services like that?
Yeah, absolutely. You know, we, we do work on, you know, major renovations. But you can look into an energy audit. There are a lot of great programs that often run through the local utilities where you can have someone come in and kind of do like a basic assessment of your home. And a lot of times those audits can be either free or at like little to no cost to you. So they'll come in and kind of do some basic diagnostics. They can run a blower door test which is going to see how leaky your house is and start to identify where those leaks are occurring. You know, is it where your house meets the foundation? Is it around your windows? Is it in your attic? It's a great kind of diagnostic test to evaluate an existing home.
And that's just usually through like your local utility company can hunt down something like that for you.
Yeah, yeah. I think if you, if you Google like energy audit and you know your state be probably a first, first place to start. You know, they'll run some kind of great diagnostics and usually give you some suggestions for tackling the low hanging fruit, whether it's air sealing or replacing your lighting, upgrading your boiler, those kinds of things.
Cool, cool. I think I just found a place online@energy.gov where they actually show you a lot of these home energy audits and list a place. So I'll put a link to that in the show notes where people could go as a way to find a free energy audit in your area. Awesome. Well, this is a tough ton of really good information, Stephanie, and stuff we haven't had a chance to discuss before in a podcast episode. You know, a lot of times we think about our body, our diet, our exercise program, but then we forget about the place where we're living all day long. So this stuff is incredibly important. And I think that if you are going out of your way to have a gym membership and go to the gym or train for a triathlon or spend a little bit of extra money on organic food, yeah, you may want to consider some of these other things like HEPA air filters or blackout shades for your bedroom or you know, working with an architect to do everything from improving the lighting flow through your home to the airflow through your home to the things that are used to build your home. If you're building a new home, this is important stuff. So, Stephanie, thanks so much for coming on the call today and sharing this.
Thanks, Ben. It was great speaking with you.
All right, folks, well, I will put all of the resources that Stephanie talks about over in the show notes for this episode@BenGreenfieldFitness.com and until next time, this is Ben Greenfield and Stephanie Horowitz from zeroenergy.com Sign down.
Visit BenGreenfieldFitness.com for even more cutting edge fitness, nutrition and performance advice. Sam.
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