What’s the Definition of ‘Green Building’?

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What’s the Definition of ‘Green Building’?

I’ve identified ten principles that show up in the various definitions of this tricky term

Posted on Nov 24 2017 by Martin Holladay

Recently I spent some time accumulating definitions of “green building” from as many sources as possible. These various definitions included ten different characteristics of green buildings.

Of course, not all definitions agree, and none of the definitions include all ten of the characteristics that I identified in the various definitions.

The three most common characteristics appeared in most of the definitions. According to most sources, a green building:

  • (1) Is energy-efficient.
  • (2) Is water-conserving.
  • (3) Uses materials in a resource-efficient way.

Beyond these three characteristics, sources differed widely. Only a few definitions noted one or more of the remaining seven characteristics that I discovered (and list below).

A green building:

  • (4) Uses materials produced in ways that minimize pollution; in other words, uses materials that minimize the environmental impact of the project.
  • (5) Uses materials and processes that are environmentally sustainable.
  • (6) Is designed for operation that minimally impacts the environment.
  • (7) Provides above-average indoor air quality or promotes human health.
  • (8) Disturbs the site as little as possible.
  • (9) Is durable.
  • (10) Is as small as possible.

The logic behind the definitions

Let’s look at the logic between each of these ten characteristics.

1. A green building is energy-efficient. Energy use is strongly associated with greenhouse gas emissions, so reducing energy consumption tends to reduce damage to our environment caused by burning fossil fuels.

There are many different ways to reduce energy use: for example, we can buy more efficient appliances, install thicker insulation, or specify windows with a very low U-factorMeasure of the heat conducted through a given product or material—the number of British thermal units (Btus) of heat that move through a square foot of the material in one hour for every 1 degree Fahrenheit difference in temperature across the material (Btu/ft2°F hr). U-factor is the inverse of R-value. . Determining whether the environmental benefits of reduced energy consumption are valuable enough to justify the cost (the environmental cost as well as the financial cost) of expensive energy-saving measures is tricky, so implementing this point takes judgment.

It's also worth noting that most countries in the world are now transitioning to energy sources that don't involve greenhouse gas emissions. Once a region completes this transition, the environmental argument underpinning energy efficiency mostly evaporates.

2. A green building is water-conserving. Almost all green building definitions include this point, and it generally makes sense. Of course, if you live in parts of Canada, Iceland, or Norway where fresh water is abundant, it makes little sense to invest in expensive equipment to save water — especially if the expensive equipment requires unusual resources to manufacture. So it's unclear (at least to me) whether this point is universal enough to be included in a green building definition.

3. A green building uses materials in a resource-efficient way. This point is tricky, but the idea is that a house that requires 8,000 board feet of lumber is greener than a house that requires 16,000 board feet of lumber.

So what’s better: a house built with straw bales that were trucked from a farm 300 miles away, or a house built with 2x6s and OSB? That’s where the math gets difficult. Good luck figuring it all out.

If you're aiming to use materials in a resource-efficient way, remember to choose materials with low embodied energyEnergy that goes into making a product; includes energy required for growth, extraction, and transportation of the raw material as well as manufacture, packaging, and transportation of the finished product. Embodied energy is often used to measure ecological cost.. For more information on this issue, see All About Embodied Energy.

4. A green building uses materials produced in ways that minimize pollution; in other words, uses materials that minimize the environmental impact of the project. This point is valid, but is hard for most builders or homeowners to assess. Is the factory where this OSB was manufactured responsible for water pollution? If so, is the pollution associated with manufacturing OSB greater or less than the pollution associated with manufacturing plywood?

If you want to delve deeply into this field, you should probably subscribe to BuildingGreen, a web site that publishes well-researched articles that try to make judgments on this type of thorny dilemma.

5. A green building uses materials and processes that are environmentally sustainable. To be sustainable, a behavior or process must be able to be continued at its current rate for 10,000 years or more, without the behavior causing any environmental degradation. Sustainability is a very high bar.

Lots of existing industries, as currently undertaken, are unsustainable: for example, peat moss harvesting, ocean fishing, and oil extraction.

Let’s say that you want to build a new single-family home in the U.S. Is our present rate of single-family home development sustainable? That’s a difficult question to answer, but I suspect not. So while the sustainability goal is admirable, it’s very hard to adhere to.

6. A green home is designed for operation that minimally impacts the environment. Operating a building usually requires the consumption of energy, regular maintenance, and cleaning. Ideally, the operation of a green building should minimally impact the environment. In this vein, it might be argued, for example, that a building that uses a solar thermal system to produce domestic hot water is greener than one that has a gas-fired water heater, or that a terrazzo floor is greener than a vinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate). floor (because vinyl floors need more frequent cleaning and energy-intensive buffing).

Ongoing operation expenses include transportation energy associated with commuting and shopping. A home designed for "operation that minimally impacts the environment" needs to be located close to jobs, shopping, schools, and public transportation.

7. A green home provides above-average indoor air quality (or “promotes human health”). This point — which on its face has nothing to do with the ecosystems that support life on this planet — has always seemed incongruous to me. Nevertheless, many green building definitions include this point, proving once again that when it comes to our cultural attitudes about the environment, it’s really not about pandas, bats, frogs, or orchids — it’s all about us.

Besides being more anthropocentric than any other green building principle, there are a few other oddities about this one. For example, it's strange that the bar is so low. Shouldn’t any home, by design and by law, conform to the principle that no home should be poisonous — whether or not the home is “green”? If our homes are poisonous — most aren’t, of course — that’s a strong condemnation of our building codes and our regulatory agencies.

8. A green home disturbs the site as little as possible. This green building principle appears in just a few green building definitions.

Taken literally, this principle dictates that homes on piers are preferable to homes with basements; that homes without any landscaping features are preferable to homes with lawns, plantings, or mulched areas; that homes without parking spaces are preferable to homes with parking spaces.

In areas subject to periodic wildfires, builders are usually advised to perform severe modifications to a building site, to make it harder for a wildfire to ignite the home. Such modifications put the “don't disturb the site” principle to the test.

This principle raises the question: should we be managing the land adjacent to our homes — those areas traditionally referred to as the front yard and the back yard — for human use, or should we be striving to mimic the natural ecosystem that existed before the house was built?

Another question raised by this principle: Do we envision that our existing home sites will someday be restored to a condition that resembles wilderness? If that’s the goal behind this principle, it seems unlikely to occur.

9. A green home is durable. The logic behind this point is that manufacturing building materials has an environmental cost, so it makes sense to design and build homes that last longer than average. It seems intuitively obvious that rebuilding a home every 50 years has a greater environmental cost than rebuilding a home every 150 years.

I’ve always been skeptical, however, of the value of durable construction specifications, and I lean toward the conclusions reached by Stewart Brand in his landmark book, How Buildings Learn. Buildings are frequently modified, and it’s hard for today’s builders to anticipate future needs. For more on this topic, see Green Homes Don’t Have To Be Durable.

10. A green home is as small as possible. While this point is easily defensible, most green building definitions avoid mentioning this issue. Needless to say, most North Americans don’t want to hear this truth.

In the United States, the first important tiny-house advocate was Henry David Thoreau, who built himself a 10 ft. by 15 ft. home in 1845. In Walden, Thoreau wrote, “I used to see a large box by the railroad, six feet long by three wide, in which the laborers locked up their tools at night; and it suggested to me that every man who was hard pushed might get such a one for a dollar, and, having bored a few auger holes in it, admit the air at least, and get into it when it rained and at night, and hook down the lid, and so have freedom in his love, and in his soul be free. … Many a man is harassed to death to pay the rent of a larger and more luxurious box who would not have frozen to death in such a box as this. I am far from jesting.”

As you might gather, Thoreau abhorred debt. He wrote, “When I consider how our houses are built and paid for, or not paid for, and their internal economy managed and sustained, I wonder that the floor does not give way under the visitor while he is admiring the gewgaws upon the mantelpiece, and let him through into the cellar, to some solid and honest though earthy foundation.”

GBA readers get to vote

I invite GBA readers to identify which of these ten principles seem important to you. If possible, choose the four most important principles, and tell us why these principles should rise to the top of the list.

Any readers who are interested in my perspective on these issues might want to read Adopting a Green Lifestyle.

Martin Holladay’s previous blog: “Revisiting Ventilation.”

Click here to follow Martin Holladay on Twitter.

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Nov 25, 2017 5:23 AM ET

My top 4 plus the one least important
by Brad S

Based on where I think residential construction is headed during the next 20 years I think the following are the top 4:

1. A green building is energy-efficient.
7. A green home provides above-average indoor air quality (or “promotes human health”).
8. A green home disturbs the site as little as possible.
10. A green home is as small as possible.

Least important is:
9. A green home is durable.

I think it's unreasonable to expect human labor to play any more than a minor role in the 2030-2038 range. In terms of physical labor humans won't stand a chance. Most of the architecture and engineering will be performed by software. Prior to 2012 I wouldn't have expected this outcome. However, with post-2012 advances in computer vision it's increasingly clear ubiquitous robotics sometime during the next 20 years is a given. 3D printing is a big deal in enabling a lot of the mechanical aspects of robotics, but computer vision is the kicker.

Part of the reason I purchased an older home is that I believe it won't exist in 20 years. I'll make a few upgrades but I need to remember everything will get demolished and rebuilt in a fairly short time frame. We're looking at a level of automation during the next two decades that is going to make human lifeways just flat out weird compared to today.

Nov 25, 2017 7:46 AM ET

Response to Brad S
by Martin Holladay

Thanks for your vote, which gets the ball rolling. Anyone else what to share their opinions?

Nov 25, 2017 2:04 PM ET

Top 4 or 5
by Robert Opaluch

Voting most important, or admitting my biases…
I’d pick five in this order:
#1 energy efficiency, though personally I view this as an affordability issue more than an environmental protection issue.
#2 water usage “efficiency” very related to #1 energy efficiency?
#9. Durability contributes to efficiency too, and makes it more usable by people. Otherwise they live with defective worn out stuff, dump it in the ocean, or pile it into landfills. Not good.
#3 Materials minimize environmental impact, again related to efficiency in my view. Cleaning up afterwards or leaving trashed areas isn’t an efficient use of natural resources.
#4 Minimize environmental impact. Clearly a green “protect the environment” issue. Finally I’m thinking like a young person? :-)

Least important:
#8. Disturbs the site. Unrealistic more than unimportant. Except for Native Americans, people disturb the earth everywhere they go. Only way to accomplish this is zero population growth a long time ago? Saber tooth tigers didn’t do their job! :-)

Comment on #10 Small as possible. Tiny homes are 200-300 SQFT, possible but not practical for a lifetime of use IMHO. I’d suggest “as small as practical.” I’ve designed a series of homes with similar construction. The smallest 560 SQFT 1BR seems too cramped for satisfied long-term use, unless spending significant time in other shared or city space outside that unit. Practical 1,056 2BR version is small but typical of 1950’s size homes, used and enjoyed for decades.

Nov 25, 2017 3:33 PM ET

May I add one?
by stephen sheehy

How about resilience? The ongoing debacle in Puerto Rico, and Maine's recent week-long power outage have reinforced my belief that houses should be able to remain habitable when the grid goes out, the roads are blocked and the sh*t has hit the fan. They should enable occupants to stay in place, cook, be warm and survive in the face of low-probability, but serious, disasters.
We're looking into battery backup for our solar array, which makes no financial sense except as an insurance policy against an extended period without grid power.

Nov 25, 2017 4:07 PM ET

by Brad S

Resiliency is a pretty good one. I don't know what that means in practical application, but it's certainly an interesting topic.

Puerto Rico is an excellent example. My feeling on climate change is that we're in the middle of the worst of it for a couple decades, it won't be as bad in the longer term future because culture and technology will change. But today, it's bad.

If a green home is meant to function as part of an ecosystem then it is also geographical and political. A large earthquake could turn my region (Seattle) into a transportation island, road access totally cut off. Not sure what would happen to the grid. Though it if damaged our hydroelectric we'd need to import electricity at a much higher cost.

Does a green home include natural disaster mitigation? Safe rooms or basements in the Midwest to mitigate tornado threat? Or maybe that's outside the scope of green building.

Nov 25, 2017 4:12 PM ET

Water efficiency
by Brad S

If I lived in Israel, water efficiency would be one of the top four for sure. They rely on desalination. California? Maybe. Get rid of the grass lawns they've had for decades, a touchy subject in California because it is part of their culture.

Nov 25, 2017 9:55 PM ET

by Malcolm Taylor

For power outages, is battery back up now a viable alternative to a generator?

Nov 26, 2017 5:41 AM ET

Response to Stephen Sheehy (Comment #4)
by Martin Holladay

While it's pretty easy to make a case that it's desirable for a house to be resilient, it's unclear to me whether resilience has anything to do with being "green" -- generally described as having to do with protecting the environment.

For human occupants, resilience is desirable. But the ecosystem doesn't care very much whether humans have electricity after the next ice storm. (That said, gasoline-powered generators produce a lot more air pollution that most sources of grid-provided electricity, so it might be argued that homes without gasoline-powered generators are more green than homes with gasoline-powered generators.)

Nov 26, 2017 5:46 AM ET

Edited Nov 26, 2017 5:56 AM ET.

Response to Malcolm Taylor (Comment #7)
by Martin Holladay

Q. "Is battery backup now a viable alternative to a generator?"

A. I would call battery backup an available alternative to a generator. A 5,000-watt Honda generator costs about $2,000. Such a generator is powerful enough to make most homes comfortable during power outages, although the generator only works if you have access to fuel (generally gasoline, propane, or diesel).

A $2,000 investment in batteries and PV won't provide you much. Even a fully charged $6,000 battery system will only help your home limp through three days without power, and if the weather is cloudy, you're out of luck after three days.

Nov 26, 2017 9:42 AM ET

Reply to Malcolm regarding battery backup
by stephen sheehy

I've been quoted around $10-12,000 for battery backup for our solar array. That's to store about two dollars worth of electricity, i.e. 12-14 kwh.

Putting it in dollar terms, it's nuts. But as insurance against an extended grid outage, it makes more sense. We managed ok during a recent six day outage, but we did lose quite a lot of food. And relying on battery powered lights got old. Going to a hotel, with the dog and cat, isn't much of an alternative.

A battery, if carefully managed, can last indefinitely over a month long outage, so long as the sun comes out once in a while. We figure we only really need a few kwh per day if we're careful. We need a few hours of power each day to keep food cold, a few minutes of running the well pump. The house stays warm for several days without power. Around here, when it is very cold, usually it's clear, so we get heat from the sun and of course solar power. In December and January, we average about 10 kwh per day, which is enough to get by. In an extreme situation, I'd need to clear panels of snow.

A generator works, but there are drawbacks. They are loud. They are also expensive to operate. Our last house had a whole house generator that used about a gallon of propane per hour or $75 per day at current price. That's $500 per week. And the cost to install is close to that of a battery backup. If we knew we'd never be without grid power for longer than a week, we'd get a cheap gasoline generator and make do. But in a Puerto Rico type disaster, would we be able to get gasoline or propane every several days? l

Nov 26, 2017 1:23 PM ET

Edited Nov 26, 2017 1:24 PM ET.

by Malcolm Taylor

I see the appeal. If conditions are favourable you end up with an unconnected net zero house - although not running at full capacity until the power comes back. You also then have made a start on battery storage, which could be enlarged later.

But surely the comparison has to be with a generator that would yield a comparable amount of power, not a whole-house one. Even a Honda 2000 would run what you need. They are quiet and use a negligible amount of gas. It does sound like presently a purely financial analysis favours a generator.

Nov 26, 2017 2:31 PM ET

Low impact now!
by Dan Kolbert

At our discussion group last month, we talked about an idea I've heard Paul Eldrenkamp of Byggmeister (and facilitator of a peer network I'm in, in addition to being someone whose judgment I've always looked to) discuss - if we realize we have a very short time frame to do something about global warming, we should be looking at materials with very low embedded energy/carbon. If the payoff is in 50 years, that may not do us much good - the up front energy load adds to the problem at the most critical time.

Nov 26, 2017 2:58 PM ET

Edited Nov 27, 2017 8:43 AM ET.

Response to Dan Kolbert
by Martin Holladay

In my view, choosing materials with low embodied energy is part of Point #3 ("a green building uses materials in a resource-efficient way"). But it's worth being explicit here -- and I agree with you and Paul.

If you are looking for resource-efficient materials, choose materials with low embodied energy.

I appreciate your comments, Dan. I have edited my article to include a reminder about choosing materials with low embodied energy.

Nov 26, 2017 4:00 PM ET

Location locatlon location
by Jon Harrod

For me, it's 1) Energy efficiency, 7) Health, 8) Minimal site disturbance, and 9) Durability, in that order.

I think it's important to frame energy efficiency and site disturbance in fairly broad terms, taking into account the critical important of location. For example, a passive house far out of town may have a larger total energy footprint than a less efficient house inside city limits, once transportation energy is considered. By the same token, a house that's infill within existing road and infrastructure networks will have a smaller "site disturbance" footprint than one that requires a new access road. Avoiding loss/fragmentation of natural areas and productive ag land need to be keystones of green buildling practice.

Nov 26, 2017 4:01 PM ET

Martin and Dan Kolbert
by Malcolm Taylor

Realistically will the choices builders make have a material effect? This is a very different question to whether we have an obligation to build responsibly. It's not a moral question, but one strictly based on numbers: If builders take up Dan and Paul Elderkamp's suggestion, does it make a difference?

What percentage of greenhouse gasses are attributable not to the building industry as a whole, but to the choices builders make?

What percentage of greenhouse gas emissions are attributable to the building industry, as opposed to the other major sources like transportation, livestock production, etc.

Does anyone have a ball park figure for what we could possibly reduce current levels of carbon emissions even with mass adoption of Dan's suggestions? I'm not trying to be defeatist, it would just be useful to know where we stand.

Nov 26, 2017 4:26 PM ET

Response to Malcolm Taylor
by Martin Holladay

For a partial answer to your question, see my article, All About Embodied Energy. In that article, I wrote:

“Twenty years ago, Ray Cole, a professor at the University of British Columbia’s School of Architecture, made some oft-quoted estimates of the embodied energy in residential buildings. Cole estimated the embodied energy of a 3,750-square-foot ranch house. According to Cole, a ‘conventional house’ has 2x4 walls and R-24 ceiling insulation, while an ‘energy-efficient’ house has 2x6 walls and R-42 ceiling insulation.

  • For a ‘conventional’ house in Toronto, the heating energy use is 136 MMBTU/year; embodied energy equals 948 MMBTU (or 7.0 years of heating energy).
  • For a ‘conventional’ house in Vancouver, the heating energy use is 101 MMBTU/year; embodied energy equals 948 MMBTU (or 9.4 years of heating energy).
  • For an ‘energy-efficient’ house in Toronto, the heating energy use is 78 MMBTU/year; embodied energy equals 1,019 MMBTU (or 13.1 years of heating energy).
  • For an ‘energy-efficient’ house in Vancouver, the heating energy use is 57 MMBTU/year; embodied energy equals 1,019 MMBTU (or 17.9 years of heating energy).”

Nov 26, 2017 4:34 PM ET

Response to Jon Harrod (Comment #14)
by Martin Holladay

Ongoing transportation costs associated with a remote location would fall under Point #6 ("a green home is designed for operation that minimally impacts the environment").

I agree that a green home needs to be located near shops, places of employment, schools, and public transportation. GBA has published many articles on that issue, including these:

Reduce the Need for Driving

Location Efficiency

Getting Around Without Fossil Fuels

Location Efficiency Trumps Home Energy Efficiency

Thanks for the reminder. I have edited my article to reflect your point.

Nov 26, 2017 5:16 PM ET

Edited Nov 26, 2017 5:16 PM ET.

Our notes
by Dan Kolbert

Here's the chalkboard from our discussion group.


Nov 26, 2017 5:31 PM ET

Edited Nov 26, 2017 5:33 PM ET.

by stephen sheehy

I think that purely from a financial aspect, a smallish generator works. But we'd need something bigger than 2000 watts, since the well pump needs 240 volts. I did a brief search. I found a 5000 watt Honda for about $4,000. Figure $1,000 for an electrician. Then we need to store it in the garage and store fuel. Ends up about half the cost of the battery system. I'm still mulling it over.

One last point. The air pollution produced by portable gasoline powered engines is appalling.

Nov 26, 2017 5:50 PM ET

Edited Nov 26, 2017 5:51 PM ET.

Response to Stephen Sheehy
by Martin Holladay

Online retailer that sells a 5,000-watt Honda generator for $2,149:

Online retailer that sells a different model of 5,000-watt Honda generator for $1,699:

Nov 26, 2017 5:56 PM ET

by Malcolm Taylor

I was thinking more in terms of generalizations. I wouldn't presume to know what is best in your situation - and no one (well except maybe Dana) has a good handle on what may happen to the grid in the future.

Nov 26, 2017 6:14 PM ET

by Malcolm Taylor

Small world. Ray Cole was my thesis advisor at UBC in the mid '80s. He made me remove the solar thermal attic I was designing into my grad project, insisting that unless I was prepared to engineer it properly, I couldn't just throw it in there as some architectural feature. He is a good guy.

Green Building seems to me to have two fundamental components. One would be a responsible stewardship of resources and our environment independent of the effect on the larger global community. The second is a response to the existential threat of climate change.

Climate change offers a unique threat in that unlike other potential problems, an architectural response that only affects the project you have control over doesn't help. I live in a high seismic zone. If I design and build projects that resist earthquakes and these projects are left standing then I have achieved something. But if I and others design our projects to mitigate the factors leading to climate change, and these design choices are insignificant in mitigating the change, then it begs the question as to why we are doing them.

I could happily adopt Dan's chalkboard list as a credo to build by. What I'm not sure of is whether it does anything about the bigger picture.

Nov 26, 2017 10:09 PM ET

We have to hope so
by Dan Kolbert

I share your lack of faith, Malcolm. Clearly we're already locked in to a pretty scary future. At this point we're at the mitigating its effects as best we can.

Nov 26, 2017 11:01 PM ET

by Malcolm Taylor

I'm glad builders like you and the rest of your group exist. It gives me great comfort - whatever happens.

Nov 26, 2017 11:37 PM ET

Stone Foundation
by Ethan T ; Climate Zone 5A ; ~6000HDD

Dan, Thank you for posting the results of your talking group. The one item that caught my eye was "Stone Foundation." Insomuch as I am writing from a building with a stone (boulder) foundation built on a Main St. in the Hudson Valley in perhaps the late 1700s and am about to start new construction on a very rocky (stony) site - I'm wondering if you could expound on this topic... are you talking Frank Lloyd Wright rubble trenches or concrete/stone foundation/walls as seen at Taliesin West?

Nov 26, 2017 11:53 PM ET

Edited Nov 27, 2017 12:00 AM ET.

Living Building - Limits to Growth and Inspiration Imperatives
by Ethan T ; Climate Zone 5A ; ~6000HDD

Martin, thank you for posting your list. In order to clarify my thoughts for an upcoming build, I started looking at the Living Building Challenge as a guide for my thoughts on the topics you bring up. The reason I did this was that I found it difficult to continue weighing all the different parameters and I figured the ILFI had done a lot of the convoluted thinking for me.

Since we were going through the motions, we then decided to at least attempt the Challenge - we'll see how or if we get there (there is also Petal Certification which is sort of like LEED Silver). One idea that I get from the LBC is that there are some disqualifying characteristics, listed in the main imperatives, which disqualify a project from being considered a green, or living building. These imperatives are Limits to Growth and Inspiration + Education.

Regarding "Limits to Growth", I think it is a reasonable assertion that humans have "conquered" enough of the landscape and that no "green" building can be reasonably built on previously undeveloped landscape. This is a tall order, I know, but I think it is one that is at least worthy of giving voice to, and one that we succeeded in passing muster for. We had to convince the ILFI that our treed village site was valid, and did so via various maps showing proximity to transit, services, and other homes.

Secondly, regarding "Inspiration and Education," I think your list is missing some form of these concepts in terms of beauty and community engagement that actually give value back to the world - a super ugly, uninviting energy efficient building is a problem. I guess, as a write in term, I would like to add "Beauty, Inspiration, and Education," as I truly believe that in some form these are crucial parts of a "Green Building."

Lastly, to your points about the difficulty sourcing various green products or healthy products, I think you are doing readers a disservice by making it sound like there are no resources available. I am surprised how much traction the Declare list (https://living-future.org/declare/) is having, and I think there is also a lot of information available regarding FSC lumber (also widely available), Greenguard, etc. You make it sound more daunting than it has to be. Sure - there are many options and tradeoffs, but there are also guiding principles which can help lead the way.

My new answer to people asking me when such and such a design feature will "pay back" is "i'm not exactly sure, but I believe it is the right thing to do." Until the fellow building a 2000 sf plastic deck can tell me when his deck will "pay back," or the guy installing a 4K TV as big as a pool table can tell me when it will "pay back," I don't see why each and every design decision in a house designed to last for the ages has to "pay back" over some prescribed length of time.

Nov 27, 2017 6:14 AM ET

Edited Nov 28, 2017 4:24 PM ET.

Response to Ethan T (Comment #26)
by Martin Holladay

Thank you for your comments.

I'd like to clarify a few things. You refer to this as "your [my] list," but I want to make it clear that I gathered these points from published definitions in books and online. In that sense, this is not my list. This is a job of reporting.

A corollary of the above point: My own list would be different. (For a glimpse of my own views, see Adopting a Green Lifestyle.)

While you have suggested that green buildings need to provide "beauty, inspiration, and education," I don't think that the ecosystem cares about those points. Like the focus on indoor air quality, a focus on "beauty, inspiration, and education" is anthropocentric. It has to do with homeowners' desires, not the ecosystem that we are currently threatening.

Finally, you mentioned that there are a lot of resources available to green builders who are confused about material selection, including the Declare list and FSC lumber. My problem with this approach to green building is it focuses on shopping, and shopping is a big environmental problem. I don't think that an owner/builder who orders a truckload of FSC lumber should feel proud. Probably the planet would be better off if we all stopped shopping -- whether we happen to be buying ordinary sheets of OSB or FSC lumber.

Nov 27, 2017 8:51 AM ET

Edited Nov 27, 2017 8:52 AM ET.

Response to Ethan T (Comment #25)
by Martin Holladay

I have a few opinions on stone foundations, since that's the type of foundation I built for my own house (see photo below).

For a new house, a stone foundation is possible but impractical. While my foundation didn't cost very much in dollars -- I gathered and washed the stones myself, so the materials (other than the mortar) were free -- it took many months of labor to build.

When all was said and done, I had a foundation wall that was neither waterproof nor well insulated.

If a green builder is worried about the embodied energy of a concrete foundation, the obvious solution is to design a house on wooden piers.


MH house cellar 1.jpg

Nov 27, 2017 1:55 PM ET

redefining "Green Building"
by William Janhonen

In my decade plus years of teaching building science I usually start by telling my classes that I dislike the term "green building" as it doesn't really mean anything. I am on a campaign to change Green Building to "Common Sense Building". This term solves many of the dilemmas faced by the listed definitions by building to a location. You must use common sense when building so you don't build on the coast of North Carolina the same way you would build in the mountains of upstate New York. Therefore as you stated in some of your answers, a cookie cutter approach will not work when locations require differing solutions to heating, cooling, moisture movement; better known as the physics of building science.
Plus it is tremendously important to note that true high performance building or energy efficient building must be designed in-it can't be pasted on. True HP/EE buildings require that everyone drinks the Kool-Aid and agrees from the design phase as to the component compatibility.
I was at the IBS show years back and saw a vendor with a huge fish tank full of water with a clock on the front. He was from Finland and had a method of creating pressure treated wood without chemicals and the clock showed how long the wood had been in the water. I was very impressed and I asked the individual how long he had been using this process? He advised me they have been using this process in Finland for over 80 years. When I asked him if this was part of the Green Building program in Finland he responded," Green Building? In Finland we just call it Building." This is the point we need to achieve where we just build using common sense according to our climate location without worrying about calling it something. Shakespeare said it best, " A rose by any other name would smell just as sweet." A home built with the proper materials using methodology providing proper ventilation, balanced cooling/heating versus climate with the proper orientation while utilizing air sealing and moisture sealing techniques would not need anything except being called a common sense home.

Nov 27, 2017 2:19 PM ET

Edited Nov 27, 2017 2:21 PM ET.

Response to William Janhonen
by Martin Holladay

I have no objection to "common sense building," and I imagine that most authors who post articles on GBA believe in common sense. No one is going to argue against it.

Being in favor of common sense is a little like believing that society should take care of widows and orphans. Who could object?

But that doesn't address the needs of the subset of builders who want to build a home that is different -- those who want to focus on building a home with minimal environmental impact.

Nov 27, 2017 6:30 PM ET

This is THE topic, isn't it?
by Andy Kosick

When we start talking about defining "Green Building" it seems to me that it quickly becomes as much a philosophical question about expectations and human behavior as it does a question of construction. With that in mind.


(10) Is as small as possible, because it's what people need to hear the most. I don't see bigger houses making anyone happier. This decision comes early in the process and has the, I think, unique ability to positively effect almost everything else on the list. This should be expanded to mean minimal geographic area as well and it should be understood that the ultimate option in this category is not to build at all.

After that it's hard to avoid...

(1) Is energy-efficient and
(2) Is water-conserving

Then probably...

(6) Is designed for operation that minimally impacts the environment or (9) Is durable. My logic (coming from working largely in existing homes) is that while embodied energy is worth paying attention to, a building's impact over time is far more important. By durable I mean it should be Durable/Recyclable, it's either built to last indefinitely or with a clear plan for the end of its useful life.

I'd like to add...

(11) Is occupied by people who understand their impact on the environment. The single most important criteria of a green building may be the people living in it, this makes education and understanding some of the most important tasks a green builder has (here's where I thank Martin for all he does). Also people, because at some point we're going to have to have a conversation about our shear numbers in the light of how we'd all like to be living, because even if we all become vegans and live in NZE multi-family tiny houses we're only going to shoehorn so many of us on this rock.

Nov 27, 2017 7:12 PM ET

The vote so far
by Martin Holladay

To score your votes, I'm awarding 4 points for every #1 choice, 3 points for every #2 choice, 2 points for every #3 choice, and 1 point for every #4 choice. High points win.

Results so far:
1. Energy efficient (15 points)
2. Indoor air quality / health (8 points)
3. Is small (5 points)
4. Disturbs the site as little as possible (4 points)

Nov 27, 2017 10:25 PM ET

More for Ethan T
by Dan Kolbert

Ethan - our discussion group is, as Mike Maines described it in "Steve's Garage" on this site, a freewheeling affair. Some items we discuss at length, some just get thrown up.

The stone foundation was an idea someone mentioned as part of a larger discussion on avoiding concrete. It did not get much discussion. I can't imagine it being a solution anyone other than someone with lots of time, no money, and a strong back would subject themselves to.

We did talk about helical piers as being a way to avoid a foundation. It does create the problem of insulation and air sealing the bottom of the house, and not gaining any ground heat, but those are more easily done than collecting, moving and laying several tons of stones.

Nov 27, 2017 11:01 PM ET

Disturbing the site
by Malcolm Taylor

The most famous proponent of this approach is Australian architect and Prixter prize winner Glenn Murcott, who urged that we "touch the land lightly". But he clarified that “Touching the land lightly is not about a building with just four columns”.

A lot of cultures have done extensive land work when they build, but end up with very ecologically sensitive dwellings. As Martin points out, what counts isn't what you do to the site, it's what you end up with and what you leave when you are gone.

Nov 28, 2017 8:05 AM ET

Edited Nov 28, 2017 8:06 AM ET.

Response to Malcolm Taylor
by Martin Holladay

I appreciate your comments. As many commenters have pointed out over the years, one important way to reduce environmental damage to our planet is to stabilize or reduce the human population. Basically, we are the problem.

That said, it's humans who are reading articles on GBA, not bears or squirrels, and the creatures who are wondering how to handle their front yard and back yard are humans. According to most moral philosophies, we have a right to live on this planet -- the idea is to do so with environmental sensitivity.

In Vermont, the climax ecosystem is either a mixed hardwood forest or a softwood forest, depending on elevation. Humans don't want to live under a dense forest canopy, because we enjoy sunlight. Most of use eat food crops, and food crops require sunlight. Human habitation in Vermont has resulted (in the early 21st century) in a patchwork of pastures, plowed agricultural land, and woods. Should all of Vermont revert to woods, and should humans live in the shade? Or can we accept some level of human-caused "site disturbance," acknowledging (as most landscape architects do) that some types of site disturbance result in beauty?

Nov 28, 2017 4:06 PM ET

Edited Nov 28, 2017 4:12 PM ET.

My take on climate change
by Brad S

"Green Building seems to me to have two fundamental components. One would be a responsible stewardship of resources and our environment independent of the effect on the larger global community. The second is a response to the existential threat of climate change." - Malcolm Taylor

Short term climate change: resiliency to extreme weather events and political response failures related to climate change.

Long term climate chage: Doesn't matter.

I'll offer an opinion that I know will be unpopular. I've talked about impact of robotics in twenty years, but I haven't talked about technology in 80 years. Even at the extreme end of -- realistic, not crackpot -- climate change projections in 2100 human populations won't feel negative impacts from climate change. Things will be so different in 2100 that adjusting green building efforts today with the goal of having a positive impact on how people live in 2100 is a complete waste of time. No matter what you do today in regard to home construction you will have zero impact on the living standards and lives of people living in 2100.

The biosphere is what it is today due to the processes embodied in modern evolutionary synthesis. However, human intent (Bioengineered Selection) will become a prime mechanism of global biological evolution by the end of the century. You might argue human intent already is a prime mechanism based on agriculture, but I'm talking about a fundamental shift in control over the mechanisms of change. What you see happening in bioengineered bacteria and yeast today is analogous to what you'll see across the entire biological spectrum in 80 years.

I'm not suggesting one should descend into nihilism. True, what we do won't matter in many regards, but it's good to do the best we can with what we've got. In addition, if you know where things are headed it helps guide where to direct your efforts today and how to construct a psychologically healthy mental disposition. For example, I wouldn't start bemoaning human activity and population growth as an existential threat to the biosphere. Yet I would try to mitigate pollution that causes health problems for people living today. Frequently, addressing acute pollution for the sake of improving population health aligns with the interests of those who are motivated to behave in a way that will "save the planet" from climate change.

Consequently, I think of Green Building within the context of local environmental impact rather than long term global ecological impacts. Yet, if you buy a product that has negative impact on a different locality you might violate the Green Building code. Granted, it's hard to buy a television -- or induction hob -- that isn't produced in a region where coal supplies electricity and the local population suffers lung disease as a result, so I give myself generous leeway to prevent neuroticism. Thus, I limit my view of Green Building to the first fundamental component of Malcolm's quote.

Nov 28, 2017 4:16 PM ET

Response to Brad S
by Martin Holladay

According to a Danish proverb (sometimes incorrectly attributed to Niels Bohr), "It is difficult to make predictions, especially about the future."

Nov 28, 2017 6:10 PM ET

The short and long term goals are not at cross purposes @ Brad S
by Dana Dorsett

Not an "or" conjunction it's "and".

Reducing health-consequential combustion emissions by replacing power plants & transportation energy with zero or low emissions energy sources is a money saving opportunity, not a cost...


...it reduces greenhouse gas emissions.

Building tighter houses improves energy efficiency & comfort...


...it improves indoor air quality, right now.

Ignoring or completely discounting long term consequences isn't good judgement. Even though all plans will inevitably change, it's still better to have a plan, and adjust as-needed to fit the evolving circumstances rather than getting stuck in the perpetual now. Fixing climate change is a lot cheaper now that it would be if putting it off while focusing on other things. Sure, there's a discount rate for paying extra now for benefits that won't appear for generations, but being cognizant of future consequences can affect present day decisions for near-zero or even negative cost, and SHOULD be paid attention to.

The error bars on the notions of transformative bio-engineering (and the potential for unforeseen consequences) are large, and doesn't constitute a real plan. But getting out of the "dig it up, set it on fire" mentality for energy production has a clear, relatively short, and low cost path, and can be planned for, even if the plans will surely change. At this point low carb renewables have an even a lower cost than the dig-it-up-and-burn-it path of the past 200 years, on a trajectory to becoming even cheaper.

The whole discussion about batteries solely as backup is misplaced, but it's pretty much stuck there by the current (totally artificial) electricity market structures. If residential rate structures start to include demand charges similar to those applied to commercial & industrial rates, batteries utilized as load-levelers could become rapidly economic for homeowners, with or without rooftop PV. Presently there is a lot more value in a home battery if it is put to use as an enabling device for higher grid throughput & provide ancillary grid stabilization services that it would ever have as Hail Mary backup for when the grid fails. Current electricity markets don't have mechanisms for homeowners to allow that use and monetize that value, but that can change, since electricity markets are regulatory constructs, which can evolve (and have) to address changing circumstances. Many aspects of electricity market regulations will change in that direction within a decade, maybe sooner in locations where the need is higher. New York's REV may well be one of the initial places where that becomes possible, but California may beat them to it.

Nov 28, 2017 8:46 PM ET

by Malcolm Taylor

I've been promised a lot of wonderful possible futures during my life. Perhaps my happiest summer was spent at Expo '67 travelling between marvellous pavilions on monorails. The whole site representing a harbinger of the wonderful way we would all live when i grew up.

The idea that we are going to engineer our way out of the problems and limitations we face has paled for me over time - as has my faith in predicting the future. I can't in all conscience leave to to some possible technological break through, or second coming, to ensure our future. I feel compelled to act, no matter how inconsequential the results. I do like to be clear-eyed about the chances of success though.

Nov 28, 2017 9:13 PM ET

Edited Nov 28, 2017 9:23 PM ET.

Response to Malcolm Taylor
by Martin Holladay

I was there too, in Montreal in 1967 -- Habitat 67, the concrete boxes with the disturbing thermal envelopes, and the geodesic dome designed by Buckminster Fuller for the U.S. pavilion. Every time I cross the St. Lawrence River on the Champlain bridge, I think back to the summer of 1967. Later that summer, I was in San Francisco, but that's another story...

Fifty years later, how come we don't have more monorails? We were promised monorails.

Nov 28, 2017 10:49 PM ET

by Charlie Sullivan

1967 was 50 years ago. Over the 50 years from 1917 to 1967 the way of life in industrialized countries changed dramatically. In 1917, there were still horse-drawn rail cars on New York City streets, and airplanes, made from wood and canvas, were a novelty without many applications outside of the military. By 1967, the concept of modern American suburban life was well established: single family houses with lawns and transportation almost exclusively by automobile. I don't blame people in 1967 for expecting equally dramatic changes over the next half century. After all, the half century from 1867 to 1917 had equally dramatic changes, so it seemed like a well established pattern.

But people's daily lives look remarkably similar to what they looked like in 1967. The sizes of the cars have gone up and down, and the sizes of the houses have gone up, but things are mostly configured in the same way. Even the airplanes look essentially identical.

I don't know what the pace of change will be in the upcoming half century, but I think it would be foolish to count on the changes being rapid, or being for the better.

Nov 29, 2017 12:30 PM ET

by Malcolm Taylor

I agree. It's also worth noting that the technological and information revolution of the past several decades is the first major change our societies have experienced that has not resulted in increased productivity.

Nov 29, 2017 1:03 PM ET

What’s the Definition of ‘Green Building’?
by Christopher Glasspool

I think there is a number eleven definition, and it is about intention, about the intention of the design, the intention of the builder, and the intention of those that make the dwelling a home. Any one of those three components can turn a dwelling Green, but embodied together, the dwelling becomes not only more Green, but also has a larger impact on the Green Evolution.
Number 10 in my opinion is really number 1, as the amount of material used per single family or single person,in my logic at least has to have the largest impact. Definition number 10 would also address multiple family residences, condos, apartments, co-housing / living, and duplexes. Green architecture is about resource conservation, and health.
I have a hard time of putting any of the other definitions as second, but number 9 is the most ambiguous, of which you touched on. It goes back to my first paragraph about intention. I have one friend in town here who designed, built and is living in a home that has no concrete or plasters, and is meant to melt into the ground after two generations, and I have another friend who designed a home that never got built, that was all about lime cements and mortar, and was supposed to stand at least 1000 years - they both are Green Goals, or at least Green Intention.

Nov 29, 2017 1:53 PM ET

Response to Christopher Glasspool
by Martin Holladay

If Americans are filling the atmosphere with CO2 at a rate that will result in catastrophe -- and I think we are -- I don't know whether our intentions matter much. Most Americans are well-intentioned, and almost everyone will happily tell an interviewer that he or she believes is protecting the environment.

Good intentions aren't enough, in my view.

Nov 29, 2017 3:13 PM ET

RE: 1967 @ Charlie Sullivan
by Dana Dorsett

"I don't know what the pace of change will be in the upcoming half century, but I think it would be foolish to count on the changes being rapid, or being for the better."

I disagree, at least partially. It would be foolish to think that at least SOME thinks WON'T change rapidly, though those rapid changes won't all be for the better.

As Tony Seba likes to point out, transition in urban personal transportation from primarily horse to primarily automotive took less than 20 years. Now that price & power density thresholds have been crossed the transition from primarily fossil fueled to battery electric automotive technology will probably take less time than that.



The cost of ownership over the lifecycle of an EV is already cheaper than fossil burners, and at the double-digit learning curve of batteries that will continue to be true even assuming fairly steep oil price deflation. The more interesting questions will be whether and how fast the transition from private ownership to "car as a service" those EVs will be, and how soon the majority will be self-driving.

The transition from fossil electricity to renewables is happening faster than most people really understand. I had a guy comment to me earlier this year something on the line of "Solar? Who cares? It's less than 2% of the power." That perception ignores the power of exponentials. The installed base of PV is doubling every two years (actually slightly less more like 22 months) , and that 1% is less than 7 doublings from 100%. Does that mean the US will be operating on 100% solar power by 2030? Clearly not, but it clearly IS a paradigm shattering shift in progress, and it's happening faster than even the most optimistic projections of 3 years ago. The cost of solar drops by about 20% with every doubling, and at the utility scale (along with wind power) is now cheaper than any other form of new generation, with a levelized cost cheaper than just the fuel & maintenance on a nuke, and soon to be cheaper than the operating cost of a combined cycle gas generator. This is totally screwing with the wholesale power markets, and the regulations will have to change to keep utilities from going under, but the transition is already inevitable, and the pace of that transition is accelerating.

Almost all new generation being built today in the US and elsewhere is now low-carb renewables, even where it isn't being subsidized or given a lot of policy support. In the US new wind exceeded all new fossil burners in 2016, and operates at a similar capacity factor to combined cycle gas (~45-50% of nameplate capacity, averaged over a year):


What was a trickle, less than 0.1% of the US grid mix a decade ago has now become a rapidly rising tsunami. The last coal plant has already been built, the last fast-ramping gas peaker in the US will probably come online next year, and it's only a matter of time before the economics of combined cycle gas no longer pencil out. There has already been one merchant combined cycle gas casualty to the daunting market forces of wind power in TX, and as more wind and solar go onto the grid with $0 marginal cost, the capacity factors of the remain combined cycle plants will be eroded.

So yeah, expect some things to change fast, others no so much, and there is always the unexpected. In 1967 a lot of analysts reasonably postulated that electricity demand would be monotonically increasing with time and scale with rising GDP, and that it would be largely met with nuclear power by now. Neither of those turned out to be the case. So predictions of how much and what type of energy sources will be in use in 2067 have large error bars, but it's a fairly safe bet that whatever it is won't be more expensive or dirtier than wind or solar is right now. There is still a lot of legs left to the learning curves of wind, PV, and batteries, but that doesn't mean that nothing can disrupt those markets. The true believers seem to think that small modular reactors still have a shot (I'm a skeptic on that one), but time will tell.

These are just the more predictable fast transitions that we're already surfing the wave on. There will surely be others, some on completely orthogonal subjects.

Nov 29, 2017 10:43 PM ET

Edited Nov 29, 2017 10:44 PM ET.

Dana and Malcolm
by Charlie Sullivan

Dana, thanks. I agree on both the general spirit of your comments and the particulars. In terms of changes that directly affect the way people live their daily lives, reconfigurations of transportation could have a major impact, and one that affects energy in some major ways as well.

Malcolm, I think that we have right here on GBA some clues as to why "the technological and information revolution of the past several decades is the first major change our societies have experienced that has not resulted in increased productivity." Duh, guys, is it because we are responding to trolls instead being productive?

Nov 30, 2017 12:50 AM ET

by Malcolm Taylor

I think there's enough time in the day to be productive and have a bit of fun too :)

Dec 1, 2017 2:22 PM ET

On resilience (comment #4)
by Marcus de la fleur

I like Stephen's suggestion to throw resilience into the mix - and unlike Martin (comment #8), I see an environmental connections.

Somebody mention food was wasted during a power outage. There is an environmental impact right there. It may be fairly small - but it is still there.

On a larger scale, take tropical storm Harvey that flooded Houston and the thousands of cubic yards of trash it generated (water damaged furniture, appliances, drywall, etc.). I would argue that the environmental impact here is hard to ignore.

Resilience could lead us to structures that can flood and dry out without major damage or without producing that enormous amount of trash. Or resilience could lead us to not build structures in places that should flood - floodplains, wetlands, etc.

In short, I see a connection between resilience and environmental impact.

Dec 1, 2017 3:05 PM ET

Response to Marcus de la Fleur
by Martin Holladay

You've convinced me that resilience details can reduce the environmental impact of a building project, so it may be worth including in a green building definition.

That said, for whatever reason, I never found resilience listed in any of the green building definitions I researched.

Dec 22, 2017 8:11 AM ET

by Robert Swinburne

Functions well and looks nice! Because otherwise it gets removed, replaced, renovated or other. Not very "green"

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