Where’s the Green in GBA?
i am a bit surprised that GBA is completely ignoring the environmental impact aspect of the “green” ! Polysterene takes from 50+ million years to never (!!!) to break down. Using this material lavishly in buildings that are obsolete in a very short time seems to me to be really, really dirty and not green at all! So, what’s up with this?
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This is a thorny question because there are many points of view on what defines green building. Admittedly, this site might be better named "High-Performance Building Advisor" if the context of "green" is environmental issues first at all costs.
We could eliminate all materials that are harmful in their manufacture and don't have acceptable end-of-lifecycle characteristics. If we took that approach to building houses, we could make a positive environmental impact for sure. At the same time, it would be more challenging to build houses that are as efficient, comfortable, durable, healthy, affordable to build and operate, and as buildable as the houses that many high-performance builders are building today. And, many homeowners would not want to live in these houses.
You have used one category of building material as an example, but all building materials can be examined with a lifecycle analysis and through that filter, few modern materials would be acceptable to an environment-first builder. However, I often wonder what the implications of working in that way would be. For example, cellulose is one of the most low-impact insulations, but could that hold true if the entire building industry abandoned fiberglass and other options and only used cellulose? Similarly, wood products look comparatively good in a lifecycle analysis, but what state would our forests be in if all of the millions of vinyl-clad houses built in that last few decades had wood siding, trim, flooring, etc? I don't know the answers, but we have to ask these questions.
Perhaps GBA could do a better job of covering the environmental impact and lifecycle analysis of building materials, and that is good food for thought. But we must balance that with all of the other characteristics that the market demands in a high-quality home or we simply will not make an impact on the building industry. Moreover, we need to help people use all materials well. We're not going to stop builders from using polystyrene products, but if we help them install them properly, in climate-appropriate, durable assemblies, we can help to keep them from entering the waste-stream prematurely.
I could go on and on with this topic and probably even contradict myself in the process, so I'm going to stop here. But this is a good question and I'm looking forward to seeing what others have to say.
Thank you for posing this question. I agree with Brian, it spurs an important conversation. (I also really like the idea of GBA covering the environmental impact and lifecycle analysis of building materials. I will make that a goal.)
My interest in building science was born of my commitment to environmental stewardship, so I very much appreciate where you are coming from. I worry regularly about the products we are using to create the built environment—their chemical makeup, their processing, their impact on natural resources, etc. I have come to the conclusion that green building is a matter of checks, balances, and trade-offs. We use plastics, foams, and tapes to ensure a building’s energy efficiency, which brings down our collective carbon output. There’s no end to the number of test results that prove today’s high-performance building materials work in that regard. But what do those same materials mean for the long-term health of the natural environment? It’s not a question we can answer yet. And that is troubling.
As a “green advocate,” I am in favor of natural building products and materials like straw bale and rammed earth. The problem is they are fringe, and adoptability and scalability are key to the building industry have an impactful role in addressing environmental degradation. It seems there is more traction being gained by building-science-rooted construction methods and materials—I’m sure there are many reasons why people are more willing to jump on that bandwagon than, say, the straw-bale bandwagon. It would be speculation on my part, and time wasted. What matters is finding the best solutions to the innumerable problems the industry is tasked with solving. It’s why this community exists—to foster ongoing and evolving conversations that lead to innovation. The exchange is invaluable and brings real-world solutions to the surface. Do I wish every solution featured all-natural materials? Absolutely. Will that ever be the case? Nope. So what is the next best thing? Finding the least harmful path forward using the wealth of information at our disposal to make decisions that result in, as Brian said, “climate-appropriate, durable assemblies” that lower embodied carbon, cut operating emissions, support occupant health, and keep the waste stream to a minimum. I believe everyone here is trying to do that.
The way I see it the word “green” is open to interpretation clearly you think green means what is best for the world’s environment. In My mind green is the building that saves the most money over time. Someone else may think the greenest building is the one that stands the longest number of years. Another may think the building that uses the least fuel is the greenest.
Almost every building is obsolete in some way in a few short years. Most are remodeled and repurposed. Very few new building will be demolished in their first 20 years.
I tend to agree with you that foam insulation especial spray foam is being overused and is becoming synonymous with quality in the public’s mind when the fact is it is mostly an expensive laze shortcut use to cover poor workmanship and or planning at the last possible moment.
Thomas, I disagree with your assertion that "GBA is completely ignoring the environmental impact aspect of the “green” !". There are many articles, questions and answers posted here than prioritize low environmental impact. I have written many of them myself.
But there is also an aspect of "do less harm." If someone is predetermined to use foam, there are ways to reduce their impact. And I, and others, argue with those who claim that buildings with a large carbon footprint are "green," no matter how much less they cost to build or operate than another building. Through the conversation, the relevant values come out.
It does get depressing when every other post in the Q+A is asking about foam in roof assemblies, but at least there is engagement and the chance to educate. If GBA simply said, "this is what Green is and this is how you must build," there would not be much engagement.
I encourage you to post an article or question that promotes what you think is the right way to build.
Not sure how long you've been reading posts here. But from my experience a lot of people get told for exactly what you mentioned, the non greeness of using virgin XPS, and are often encouraged to source recycled foams or use other materials.
I personally enjoy the technical and performance side of things and do what I can to be environmentally friendly. If I wanted to be totally "green" beyond everything else I'd join an earthship forum.
>"i am a bit surprised that GBA is completely ignoring the environmental impact aspect of the “green” !"
Completely ignoring... whhaaat... ??
I might infer that you may not have been paying close enough attention(?) or haven't been on this forum very long! These issues get discussed fairly often.
More likely it's just a bit of a troll...
(Now rising to the bait... Mmmmm chum! Yummy! :-) )
All stone or earthen buildings buildings may be low-impact from a materials input point of view, but in most locations that won't meet the comfort needs/wants (or even building-codes) of modern human occupants without huge energy inputs. Some insulation of some type is called for to manage the energy & comfort balance.
A reasonable quick reference for the relative verditude (at least from a global warming perspective) of building materials (including insulation) can be found here:
Note that the difference in impact between fiberglass or rock wool vs. EPS isn't dramatically better R-for-R. See:
And while other insulation materials are net-negative (as sequestered carbon), those materials are moisture susceptible and can't be used everywhere (say on foundations & slabs) without risk of failure. Very few people posting here advocate "....Using this material lavishly...", and this is a topic that I warn against several times per month (most months). Where foam is necessary or otherwise desirable for moisture control I'm big fan if using reclaimed roofing foam in lieu of virgin stock goods, something I recommend here regularly.
Lavish use of concrete is also something to be concerned about, given the high global warming footprint of portland cement. For that reason I'm definitely NOT a fan of insulated concrete forms for anything but foundations. YMMV. I'm also not a fan structural insulated panels, ESPECIALLY those made with closed cell polyurethane rather than EPS. Again YMMV.
Dana keeping in real yet again. :)
I doubt very much anything manmade is going to be around in 50 million years, certainly not in any recognizable form. I've seen those "plastic lasts forever!" statements before, but that's really not the case. Plastics are polymer chains -- long chains of carbon atoms with various other groups hanging off the sides here and there. Exposure to ultraviolet light RAPIDLY breaks down most of those polymer chains, polystyrene included. You can run a quick test yourself: put a styrofoam cup outside in the sunlight and watch what happens. It won't even last a few years. Everything degrades, even plastics.
That said, there is more to this than just "it doesn't degrade!". Do you really want your house made of entirely biodegradeable materials that will break down in a short period of time? Are you actually being green by purposely building a home that will need to be rebuilt in a few decade's time? And I don't mean it needs to be rebuilt because it's outdated, I mean it needs to be rebuilt because of literal decay -- materials decomposing which will lead to structural failure. We actually had another member on here who was advocating for homes to be built to last 1,000 years a while back, and his argument was that was greener because they'd last LONGER. While I don't really think a 1,000 year home design is necessarily the best solution either, there are some who would argue that longer lifetimes are better than short ones for building materials.
There is also the total lifecycle consumption of the HOME itself. This includes energy use. Does the energy saved over the life of the home by the use of that foam at construction time exceed the amount of energy it took to manufacture that foam? I think in many cases that's probably going to be "yes". So now that insulation has a net benefit in terms of long-term energy use reduction.
These are complex problems and there are no easy answers. I caution everyone to be wary of anyone who offers simple solutions and claims they're perfect in all cases.
BTW, Dana might be right about the troll, but who can resist the occasional troll bait? Good to see you back again too, Dana.
Although i was born in a rural, forestry area way up in the alps I’m not a troll… 🤪 which you would also realize if you googled me…
Re: polystyrene decomposition: https://sciencing.com/long-styrofoam-break-down-5407877.html
Re: building for longevity and building with “non-green” materials: a good trade-off needs to be found. Either extreme is nonsense. Where the right trade-off lies, as always, depends on believes, knowledge (lack there off) and conscientiousness.
Re less problematic walls: google dr erwin thoma - unfortunately, most is only in german, but google translate might do well enough job to get the drift.
He suggests 100% wood walls and ceilings. No glue, no nails or screws, just doweled together. They offer to come and disassemble your walls when you don’t want the house anymore and reuse the panels. Can’t explain the whole thing in short. They have been experimenting since 70s 80s i believe, and are building houses large and small with these panels for some 20 years with amazing results - insulation-, airtightness-, and air-qualitywise. Not perfect either, also has disadvantages. But, seems better to me than creating a pile of toxic waste - which demolished buildings end up being…
Re insulation: i have had great success using wool insulation. Doesn’t lose function when it gets wet, like rockwool and fiberglass does. Is not dangerous to your health (no protective gear needed when installing it!), regulates moisture, and much more. See: https://havelockwool.com/
My lament is, that material toxicity and environmental impact is too low on the list of considerations - that’s all
Thank you all for engaging in the discussion!
I don't think it's useful to dismiss posters as trolls because their views don't align with the general consensus on GBA.
I don't think anyone dismissed the poster. Both myself and Dana mentioned this "might" be a troll, but we also both posted thought out responses too.
I don't have any problem trying to build reusable structures, or using only naturally occurring materials, I just don't think that's useful on a large scale due to labor, energy use, and other issues. In some cases, natural materials can present their own issues (such as wool carpet shedding fibers, where polymer carpet does not).
As I said, these are complex issues with no easy answers, and also no "one size fits all" answers. It's good to see other perspectives though, and some of those other perspectives have certain things of merit that can possibly be incorporated into the larger industry. I would not ever want to dismiss any potential positives just because they didn't fit with the current consensus.
There are too many examples of inventions that were dismissed at the time because someone lacked the foresight to see where they might lead. Some notable examples are the transistor (the first prototype looks like a high school science project), the now-ubiquitous Liquid Crystal Display (LCD) that nearly everyone is probably using to read these posts (the inventor almost got fired from his lab for wasting his time on a "useless" technology), and the adhesive on 3M's "sticky notes" (which was supposed to be a new type of superglue). As I recall, silly putty was supposed to be a lubricant too.
It comes up on occasion, but it's also important to remember that local material availability matters. If "exotic" green insulation is not available locally, purchasing/shipping it does not necessarily result in carbon savings.
Similar considerations apply to alternative and/or high performance building practices and the local labor market.