More Building Matters
When people say, “Earth’s climate has always changed,” I think back to a college geology class I took in 1992. The professor’s PhD research specialty was drilling deep in glaciers, peering back hundreds of thousands of years, and comparing carbon dioxide (CO2) levels with surface temperatures. My professor would agree that both temperature and carbon-dioxide levels have always varied. But he would add that they have always correlated very closely with each other. The relationship is complicated, with higher temperatures often preceding higher CO2 levels, but they always end up following a similar path, largely because of what we now know as the greenhouse effect—the CO2 and other gasses trap some of the sun’s energy from leaving the atmosphere. The problem is that CO2 levels are now much higher than ever before, and the temperature is just beginning to catch up. (CO2 is not the only greenhouse gas, but it’s by far the most common, so it is used as currency: other greenhouse gasses are typically converted to the damage they would do if they were CO2.)
Even with supercomputers, scientists can’t predict exactly what the results of climate change will be, any more accurately than they can accurately predict the weather for next week—there are just too many variables to consider.
But just as we know within a certain range what the weather next week will likely be, scientists have an increasingly accurate picture of what the future holds for us, and it’s not good.
In October 2018, the United Nations released a report from their International Panel on Climate Change, summarized with, “Large, immediate and unprecedented global efforts to mitigate greenhouse gasses are required.” Previously, the Paris Agreement had bound 200 nations to keep temperature rise to 2°C, but the IPCC report cites 1.5°C (2.7°F) as the maximum we can reach without catastrophic results. While a couple of degrees may not sound like much, it will have enormous impacts on the world as we know it: stronger storms, acidifying oceans (and the associated loss of shellfish and coral reefs), a weakening gulf stream in the Atlantic that would cause much colder and more extreme weather in Europe, and the decline of species and ecosystems. Increasing drought and higher temperatures will cause migrations that will spark hostility. Some sources seek to inject uncertainty into the UN’s predictions, but the vast majority of the world’s scientists agree and are already measuring the changes as they occur, though they are often all but impossible to observe directly. A 1°F temperature rise isn’t exactly obvious.
Believe it or not, buildings do matter
This is the biggest challenge humans have ever faced, and it requires the world to act together for this common cause. Every action, large and small, has consequences, and this is an unprecedented opportunity to work together. We need to drastically reduce carbon emissions, and we need to prepare for the possibility that we won’t be able to prevent climate change from accelerating.
Buildings have a big impact on greenhouse gas emissions, in two ways: (1) their operating energy, the total impact of the energy needed to heat, cool, and ventilate a home or other building, and to power its lights, outlets, and appliances; and (2) their embodied energy, which includes everything needed to create and install a material or product and, some argue, to recycle it as well.
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In the United States, both operating energy and embodied energy are heavily dependent on fossil fuels. Globally, almost 40% of energy used is related to building construction and operation. The only country that contributes more greenhouse gas emissions than the United States is China, which has twice our emissions but four times our population. According to the Department of Energy, U.S. buildings account for 39% of primary energy consumption and 72% of all electricity consumed domestically, and together they contribute more to total greenhouse gas emissions than either the transportation or the industrial sectors. Including embodied energy, the United Nations calculates the impact of U.S. buildings to global warming emissions at 48% of our total emissions.
What we can we do about it: Small steps
The ways to reduce energy consumption are well known: improve airtightness and insulation levels; install efficient windows, doors, fixtures, and equipment; design to take advantage of the sun’s rays (while guarding against overheating); be smart about how you operate your home.
Energy improvements with a return on investment of 5% or higher are a safe place to put any extra money, and even lower returns can represent an affordable donation toward environmental stewardship, with better returns than bank savings accounts. |
Some simple ways to reduce operating carbon are to use LED bulbs (with the variety now available there is no excuse for people still clinging to incandescents or halogens). Air-seal your home; as much as 50% of energy lost is through air leaks. Add insulation. Install more efficient equipment. Be ok with being a little warm in summer and a little cool in winter; previous generations were not the wimps that we have become. More-efficient envelopes can be more susceptible to mistakes, so learn the building science needed to make them safe or hire people who already understand how to do it. It’s not hard, but it is different than building in 1950. Net zero energy homes—those that generate as much energy as they use on an annual basis—need to be mainstream, not niche.
To go a little further, like many designers of efficient homes, I use an energy modeling program to weigh building options: everything from overall shape and orientation to window and equipment selection to wall and foundation systems. I use BeOpt, an energy modeling program that is simple to use and a free download from the Department of Energy, and show clients the return on investment to go above code-minimum construction. BeOpt’s most unique feature is that it can automatically show the most financially-prudent path to specific energy use targets, all the way to net zero or net positive annual energy use, using nationwide average costs. The user can modify costs or add new assemblies to the substantial list programmed in. I tell clients that considering the stock market is due for a slowdown, energy improvements with a return on investment of 5% or higher are a safe place to put any extra money, and even lower returns can represent an affordable donation toward environmental stewardship, with better returns than a bank savings accounts or similar low-risk vehicles.
Finding the balance point between expenditures and gains is also the intent behind the Pretty Good House approach to home design and construction, which you can read more about at Prettygoodhouse.org.
Traditionally, operating energy has been considered much more important than embodied energy, as the overall emissions from operation for a typical building are around 80% over 50 years compared to 20% for embodied energy. But with the climate clock ticking, it is critical to reduce embodied energy as well. (Read The New Carbon Architecture by Bruce King for a thorough analysis.)
The simplest way to reduce the impact of the materials used is to use less of them: design and build smaller homes, renovate instead of building new, recycle or upcycle whenever possible (and use materials that can be reused in the future), shift to multi-family buildings instead of single-family homes. Another is to avoid materials that contribute more heavily than others; two common construction materials strongly tied to global warming are certain types of foam and concrete.
The most readily available and affordable rigid foam, extruded polystyrene (XPS) uses blowing agents that are 1400 times more damaging than CO2. There are two viable alternatives: polyisocyanurate and expanded polystyrene (EPS). I have been designing high-performance homes on tight budgets for over five years, without specifying XPS, so it is possible—it just requires a little more legwork to get the right materials. (Note that I said I had not specified XPS; it still shows up occasionally because it’s so versatile and easy to get that builders sometimes use it instead of what I spec.) Conventional closed cell spray foam has blowing agents that are almost as bad as those in XPS.
Many cast concrete footings are oversize, built to standard sizes instead of optimized for their particular sites and structures. Foundation walls are often thicker than they would need to be if they had proper steel reinforcing and were allowed to cure slowly. |
Concrete is the most commonly used construction material in the world and the Portland cement in it is responsible for more than 8% of total CO2 emissions. It’s not going away, but it is possible to reduce its impact. The easiest is to simply use less of it. Many cast concrete footings are oversize, built to standard sizes instead of optimized for the site and structure; foundation walls are often thicker than would need to be if they had proper steel reinforcing and were allowed to cure slowly. Where basements are common they are rarely necessary, and they require more concrete and insulation (almost always climate-damaging foam) than a slab foundation. It’s even possible to minimize the amount of foam used in a slab-on-grade foundation; I recently designed a small house with a concrete-free slab; we simply ran an insulated grade beam around the house, and inside that we floated a wood floor over high-density EPS foam. I’ve also been specifying concrete with pozzolan admix, which uses industrial wastes (typically fly ash) to replace part of the Portland cement while maintaining or improving the strength. Another, new technology injects CO2 captured from factory emissions into concrete, resulting in a stronger concrete and capturing the greenhouse gas. CarbonCure, one producer in this category, is already available at limited plants around North America.
Building-science discussion groups are popping up; if you don’t know of one, start one. |
Buildings that use less energy and have less embodied energy require a deeper understanding of construction than we needed in 1950 or 1970, so we should expect that more education is necessary to design and build good homes than in the past. There are many educational sources, but one I recommend is to find or start a discussion group. For the last ten years a building science discussion group has met monthly in Portland, Maine, led by builder Dan Kolbert and hosted by Performance Building Supply, and was the source of the Pretty Good House concept. Last spring I started a similar one near me (search “Building Science + Beer” for more info.) Similar groups are popping up elsewhere; if you don’t know of one, start one. Just getting professionals and interested parties together in one room for an informal, open discussion leads to a surprising amount of learning and relationship-building. There are also more formal groups: NESEA, Architecture 2030, Passivhaus/Passive House, USGBC to name a few that I have found valuable.
What we really need to do: Giant leaps
Ideas such as those above are a start and should be the minimum level of thought put into any new home. Unfortunately, the situation is dire, and much stronger action is needed, including:
We need policy changes to force the free market to respond. There are some things that industry and individuals are just not inclined to do without pressure, even when the result will be strongly positive for everyone. The free market can be a wonderful thing, but it’s not good at everything, and has not proved effective against climate change; we are at the point where we need government intervention to encourage behavior in the right direction—and not just our government, as the US does not exist in a vacuum. Very little in the market is not controlled in some way, and fossil fuel production is heavily subsidized in various ways; instead it needs to be taxed, with the earnings going toward policies and technology to help us through this next age of climate change. A carbon tax is the simplest and often-recommended policy change, in use and effective elsewhere.
An efficient home may use $300 per month less in energy costs than a poorly built home, money that could go toward a mortgage. |
We need to greatly reduce operating energy in all our buildings, through efficiency measures and through cleaner forms of generation. The Passivhaus program was designed in the 1990s to limit each person’s building-related emissions from contributing to climate change. It’s very hard to meet the standard with single-family homes or in more extreme climates, and relatively simple with multi-family dwellings—a hint at which is better for the planet. Going further, the Living Building Challenge charges participants with creating buildings that use fewer resources of all types than they take to build and operate. It’s a challenge indeed, but also quietly setting a new direction in the high-performance world.
The LEED standard has been effective for institutional buildings but the initiative has run out in the residential sector. Building to Energy Star standards is popular where it is subsidized, but the standards are not particularly stringent, and many states don’t provide incentives. Architecture 2030 aims for all new buildings to be carbon-neutral by 2030, 20 years ahead of the timeline set in the Paris Agreement, but in alignment with the recent UN report.
New buildings need to be carbon neutral to meet the necessary targets, but the existing building stock contributes much more to operating energy use; we need mass weatherizing and equipment upgrades. |
Banks need to consider operating costs when providing loans. An efficient home that uses $300 per month less in energy costs than a poorly-built home could pay for a $60,000 larger mortgage to fund the energy improvements and solar power generation. A few banks are already doing this but it’s rare.
For power generation, arguments against subsidized photovoltaics are valid, as they favor those wealthy enough to afford a PV system. But those are typically the same socio-economic class of people who also profit from owning stocks in subsidized fossil fuel companies, so the argument does not hold up to scrutiny. The more PV that gets installed, the more affordable they become, and the more they contribute to a stable, distributed energy generation system. But those smaller systems are not being built quickly enough; what we really need is much more industrial-scale renewable power generation. As an aesthetically-oriented environmentalist I hate to see the changes these power generators bring to the viewscape but compared to the alternatives I don’t think we have a choice. At least creative farmers can graze animals among PV fields and wind turbines. (The UN report also had a harsh critique of industrial animal-raising practices, but some encouragement for small, diversified farms including multi-species rotational grazing, which dovetails with using fields for PV generation.)
We need more housing to accommodate a population that, for better or worse, will continue to grow. But we can’t all live in 3,000 sq. ft. custom homes in the countryside. At bare minimum, we need to build smaller, more efficient homes, but we really need to be building multi-families buildings, which are a much more efficient use of resources. New buildings need to be carbon-neutral to meet the necessary targets, but existing building stock contributes much more to operating energy use; we need mass weatherizing and equipment upgrades.
As for materials, one technology that is nascent in the US but has proved itself elsewhere and is gaining traction in the US is Cross Laminated Timber (CLT). It will probably never pencil out for single-family homes, but it has long been used in Europe for larger buildings, where it can replace a significant amount of the carbon-intensive concrete and steel normally used in such buildings. If it comes from a sustainable source it can be a strongly carbon-negative material, meaning the more we use, the more we save, for buildings where steel, concrete, and foam or mineral wool insulation would normally be used.
Some approaches are on the fringes, but as consumers become educated about alternative ways to build, they are becoming more popular: straw bale construction, high-performance offsite construction, tiny homes (on or off wheels). All have tradeoffs compared to conventionally sized and built homes, but each has advantages.
Use local materials. While moving large quantities of products from one side of the globe to the other can take a surprisingly low amount of energy on a per-unit basis, the heavier the product the better it is to buy local, especially if buying local supports your local economy. In Maine, the most heavily forested state in the country (on a percentage basis), the most affordable wood siding comes from the west coast. We are just now getting our first CLT plant, and research is under way on wood-fiber insulation, long common in Europe.
What if we don’t do enough?
We are at the most critical juncture in human history. Your future self, your children, and your grandchildren will know that you had the opportunity to do something now and either chose to or chose not to. Every decision matters. |
The United Nations’ recent report has set a dire prediction. We will find ways to do better, but we all must prepare for a more severe climate (including stronger and colder winters) and what that will do to various societies. The damage we are inflicting today won’t be fully felt for decades, so it’s hard to focus attention on something that feels intangible. But we don’t have a choice. I recently described the situation to someone who was trying to convince me to focus on serving the needs of those who suffer from Lyme disease, currently at least 200,000 Americans. A noble cause, and their needs are real, but compare 200,000 individuals with every single person and other animal on the planet. Just in the next hundred years that’s at least 20,000,000,000 people who will be affected, many severely. That’s 100,000 times more people than currently afflicted with Lyme disease in the US, and more than 50 times our current population. Our failure to act will mean all of them will suffer, and many species will be eradicated, because we couldn’t act in time. And that’s just in the next 100 years. Consider the common question, “if you could go back in time and change one thing, what would you change?” We are at the most critical juncture in human history. Future-you, your children and grandchildren will know that you had the opportunity to do something now and either chose to or chose not to. Every decision matters.
With the significant changes that will likely happen, despite our efforts, we need buildings that are more resilient in the face of stronger storms, longer droughts, and potentially questionable power supply. We need to show developing countries how to build resilient communities that are interdependent and secure. (And we could learn a lot from the low-impact lifestyle often practiced, out of necessity, in developing countries.)
What if we don’t need to do anything?
There is the slimmest of chances that climate change deniers are right; after all, this is science that is impossible to prove with 100% accuracy, and the climate and its interaction with all of the earths’ systems is a big, dynamic thing. What if all of the societies on the planet work together toward a common goal, instead of warring over resources? What if people had cleaner air, lived in healthier homes, lived healthier lifestyles and had more close relationships, in more comfortable homes? What if we support local economies instead of sending our money overseas and complaining that locals don’t have work? What if we are better prepared for droughts, storms and power outages? What if we better understood the connection between ourselves and our planet’s ecosystems? Wouldn’t those all be good outcomes?
20 billion people and incalculable species are depending on you to do the right thing.
-Michael Maines is a builder and designer in Palermo, Maine. He is a contributing editor to Fine Homebuilding magazine. Photo by Alexander Andrews on Unsplash.
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33 Comments
GREAT article! One thing I'd add...overpopulation and projected human population growth was considered a serious problem when I was in college nearly 50 years ago. Aside from China adopting a "one child" policy for many years (now discontinued), nothing seems to have been done to address human overpopulation of our planet. Our species is destroying the planet and other species because there's just too many of us, using limited resources and dumping waste everywhere. Not to mention USA pets overpopulation, or our introducing invasive species!
And human population is exploding not steady state. Overpopulation has contributed to pandemics, mass starvation and poverty, ethnic hostilities and widespread wars, not exactly the best solutions to controlling human overpopulation. The notion that increasing birth rates will help nations economically is misguided.
We need to consider limiting population growth rather than take it for granted. We wouldn't be worried about our impact on the planet if there were far fewer of us humans thereby doing less damage. And maybe we'd be building smaller and fewer buildings if we addressed overpopulation in some ways.
The venerable Malthusian Trap and soon Eugenics will real its ugly head. Lets not go down that road again.
The top house picture looks like a scene out of the movie - The Book of Eli :)
In that scenario, climate change happened abruptly when WW3 happened and the world powers decided to unleash nuclear bombs. Hopefully we are not faced with that scenario, as all the energy efficient practices we employ will not matter in that scenario. Depending on your world view, the above fictional but possible scenario may be where human civilization is heading to, hopefully not.
As far as population control. A male getting a vasectomy is a simple 30 minute out-patient procedure that costs under $1k or sometimes free if you have insurance coverage. The human population issue has a deep religious factor. Secular societies birthrates have actually held steady or declined but in religious territories, the population is exploding.
The Pew Research study stated, "The world's total population is expected to rise to 9.3 billion, a 35% increase between 2010 and 2050, However, "over that same period, Muslims, who have a comparatively youthful population with high fertility rates, are projected to increase by 73%." Muslim growth benefits from the fertility factor because "globally, Muslims have the highest fertility rate, an average of 3.1 children per woman." This is above a replacement level of 2.1 which is "the minimum typically needed to maintain a stable population."
https://www.pewforum.org/2015/04/02/religious-projections-2010-2050/
How do we know the world is overpopulated? By just believing what we are told? We do not know how many people shared the earth years ago for comparison. World population can fit in Massachusetts and comfortably in Texas. All you have to do is look at all the unpoplulated land in the world to see how you are being deceived by the globalist who want the world for themselves and their prodigy. Do you really trust or know who these researchers are who claim there is a rise in CO2? If you are so concerned, then go plant a tree and refuse to build corporate buildings that spew waste and CO2 into our world. Stop the ever ongoing wars with their inefficient tanks and planes and other weapons of mass destruction that do more damage then 95% of the human population. Tell all other life forms they can only have one offspring and see how that goes. What about the world's oceans. Should we decrease the fish population too so the oceans of the world don't get overcome by to much CO2? Use your heads people and stop believing the lies we have been told by those who are to stupid to get real jobs that contribute to society rather than try to control it.
To all those who feel we need to reduce the world population, set an example....you know what you gotta do.....
Part of the problem revolves around incentives. Namely govt incentives. By in large the state incentivizes sprawl beginning with road construction (public financed), cheap access to residential mortgage credit (GSE's), insurance schemes (ex. Flood Insurance, Wildfire), public utility schemes.
Removing these incentives would result in higher population densities in areas less susceptible to natural disasters and a reduction in per capita energy use.
A small change to insurance programs to favor rebuilding in a less risk-prone area over rebuilding in-place after flood / wildfire could go a long way.
Fabulous post !
There is much opportunity for efficiency improvement in existing housing. I have worked with my neighbor on eliminating ice dams from their 1977 built 2 story with 60% cathedral ceilings. I monitored the house prior to any work being done and the heating energy use was 5.49 Btu/sf/hdd (Btu's per square foot per heating degree day). The work on the ceilings is complete with comprehensive air sealing and insulation to R-49. The first 2 months of this heating season is showing an energy use of 4.02 Btu's/sf/hdd. Ice dams appear to be eliminated. Additional efficiency improvement can be realized when the forced air furnace is replaced going from 80% to 95% efficiency along with an ECM fan for reduced electrical use. My math says this would put the Btu/sf/hdd number at 3.6. With just 2 changes, one to the building envelope and the other mechanical, quite a drastic reduction in natural gas usage is realized. There are other areas in this home that could use improvement namely some lower level air sealing and rigid insulation on the foundation walls.
Minneapolis/St. Paul is filled with homes ready for efficiency upgrades. Cheap natural gas over the years keeps these projects on the back burner. It is the thing to do however, a dedicated funding source and clearinghouse for these projects would go a long way. We have the knowledge to do these projects safely and cost effectively, time to do it.
Michael Maines writes an interesting and though-provoking blog about how building practices can help alleviate climate change, and half the posts wander off into the weeds on topics only tangentially at best related to what he is discussing. Surely the site is called Green BUILDING Advisor for some reason?
Another way energy efficient buildings can be advertised is that an efficient home offers comfort and less money to be spend on heating/cooling utilities. My energy efficient home is super quiet, comfortable in both winter and summer, no leaky drafts, no insect/rodent infiltration issues, and my utility bills are dirt cheap. Those reasons can be used to "sell" better buildings, even if one doesn't care about climate change issues. We have to face the fact that there are some people who don't believe or care about the climate change issue and therefore other techniques have to be used to get them to want an efficient home.
Someone needs to study the rodent infiltration thing. I know lots of homeowners who would jump at rodent elimination before airsealing. After all, a house "needs to breathe" but it doesn't need mice. :D
Where do you live? If using exterior rigid foam every house built east of the Mississippi in CZ 3 or lower would have the potential of being infiltrated by carpenter ants/termites.
>"...there is no excuse for people still clinging to incandescents or halogens..."
You mean the folks with the motto, "You can have my light bulbs when you can take them from my dead, burnt, crisp hands."??? :-)
Incandescent bulbs are even still sold in Germany (as space heaters for the poultry industry.)
>"For power generation, arguments against subsidized photovoltaics are valid, as they favor those wealthy enough to afford a PV system. But those are typically the same socio-economic class of people who also profit from owning stocks in subsidized fossil fuel companies, so the argument does not hold up to scrutiny. "
People who are wealthy enough to buy NEW homes ( particularly CUSTOM BUILT homes) are generally in the same socioeconomic class as those who can easily afford PV, as well as affording an accountant capable of showing the the math on the present value of that investment. The Federal mortgage interest deduction subsidy is a bigger deal than the PV subsidy for most.
Surveys show that the populations who actually INSTALL PV are heavily weighted toward the middle class, not the upper-middle or wealthy, and not the people who are making their living off the capital gains of their investment portfolios:
https://www.greentechmedia.com/articles/read/hard-times-for-solar-companies-means-good-times-for-solar-buyers
"The solar industry in the U.S. still has a lot of room to mature and grow. The typical customer is a middle-aged, middle- or upper-class, a homeowner and usually male. There are plenty of other customer classes, however. (GTM Research and PowerScout recently analyzed the income levels of solar customers and found that 70 percent are middle-income.)"
Bottom line: Most people rich enough to be buying a new home can also afford the PV to run it, subsidized or not. People who can't afford the PV also can't afford the custom house, mortgage interest tax subsidy or not.
I'm with Dana. Many of us who frequent GBA are not in a position to walk the walk financially. I heat a very under-insulated house with wood off my own land. However, when I fly across the country, (rare indeed - I try to minimize air travel in favor of trains) I look down and see the vast thickness of human habitation and think " a new house here and there in all that doesn't make a lick of difference" But we still have to try don't we? Saving up for PV in VT....
I wonder how many of those middle-income PV buyers used PACE loans?
A pv system for the average house, after federal credit, costs about a third as much as a new pick-up truck.
As much as I would love a solar array on my all electric home, I can't justify it with the utility averaging $75 month, approx 500 KWH monthly for a 1400 square footer with basement, code built home that's fairly tight and R50 attic. Replacing the aging HVAC system and refrigerator will probably drop another $20 bucks off the bill. Seems simple enough.
We need it solved at the utility level, not on an individual basis.
New trucks and vans are a necessity to the tradesman who puts 80000-100000 miles a year on a vehicle. Better gas mileage wouldn't hurt.
> both operating energy and embodied energy are heavily dependent on fossil fuels.
Sometimes, but not reliably enough to use energy efficiency as a proxy for carbon efficiency. For example, Seattle claims their electricity is 97% fossil fuel free.
If you care about carbon, I suggest calculating carbon. It's not hard to be more accurate than the quote.
> what we really need is much more industrial-scale renewable power generation.
Agreed, large scale wind and solar are far more carbon efficient than residential scale solar.
Why not just ban detached single-family residential construction?
I lived in a 400 square ft apartment in Portland Maine years ago.
12 units total in a tiny building.
The ceiling above me, someone else's floor. I'm almost certain a Madame was operating a brothel upstairs.
I prefer single family detached, 5 acres minimum. Go and try it, you'll eat your words.😁
See my reply to Mr. Wheeler below.
John, why don't you go live in an apartment building and leave the rest of us alone? Your idea would work in North Korea quite nicely.
Tom,
I'm pretty sure john was being facetious. Calm down.
I am partly being facetious however based upon various suggestions it is the only logical step. I've seen posts which suggested that policymakers should limit the size of homes based on some definition of "need". How is that any different than requiring PV, banning NatGas hookups, banning certain mixes of concrete or banning foam product (speaking to you 475 building supply)? Why not just require all detached homes be built out of straw bales? Too radical you say?
There are policymakers who under the fear of climate change would figuratively have no problems forcing almost everyone into a multi-family flat, give them their govt allotment of recyclable clothing which comes in some shade of beige next to their weekly allotment of food.
That is of course unless you can sell your urban home at the top of the market cash out some stock option and then using those proceeds build a passive house which is priced well outside local market hundreds of miles away in BFE so you can sit on ones patio and pontificate about how getting back to nature has made life so much more satisfying while meeting the govt requirement of BTU's per square meter.
Btw...N Koreans have a low carbon lifestyle. ;)
We know how to reduce carbon, the question is how to do it in ways that people find acceptable. Ie, doesn't change their life too much.
Better than lots of rules is carbon taxes - then everyone wants higher pozzolan concrete without knowing or caring about carbon impact.
Here in SE Michigan where basements are common, there are some big factors not related to efficient use of materials and low operating expenses that would need to be addressed to encourage a switch to slab construction.
#1: Taxes
If I want a house with conditioned space to store things, a 3000 sq. ft. ranch on slab is going to have higher taxes than a 1500 sq. ft. ranch on a 1500 sq. ft. basement.
#2: Lot restrictions
If I just want space to store things and don't care about whether or not it's conditioned (or even directly attached to the home), that space will be considered as a garage or accessory structure and subject to limits on square footage vs. home size and / or lot size.
1500 sq. ft. ranch on basement + a 600 sq. ft. attached garage = OK
1500 sq. ft. ranch on slab + 600 sq. ft. attached garage + 1500 sq. ft. accessory structure = Not allowed
#3: Builder pricing models
The traditional pricing models of local builders I've seen usually just lump things into a generic $ / sq. ft., with the basement cost being just a small upgrade charge or essentially "free".
Point #2: In the SE US basements are rare so garages are almost always attached and storage is either above the (2nd floor access) garage or in an attic space if the space above the garage is a bedroom(usually master).
Point #3: In addition due to the rarity an unfinished basement will cost $30-$50k extra vs slab.
Goes to show how different local market conditions can be.
Not sure that the cost to build basements here is really all that different, but a house here with a basement vs. without will usually go pull in at least $30-50k extra, so it's almost always in a builder & buyer's financial interests to include one.
Also worth factoring into local cost considerations -- most trades here vastly prefer working on plumbing / HVAC / etc. where most everything is run through the basement ceiling vs. needing to enter crawl spaces, open up walls, or work in attics. End result is that the labor rates for work lead to a lower long-term TCO for a house with a basement.
It's hard to make a comparison, partly because basements aren't the concrete walled open spaces they were. Here a new-build, code compliant basement needs insulation, ventilation, wiring, and drywall to the four ft level. At that p0int it usually makes sense to fully finish it - which means it's cost is comparable to any other part of the house. That also means the accessibility of the services for maintenance or renovation disappears. All that for a somewhere that yields poor spaces with no windows, difficult egress, and that is susceptible to water damage. Put the same money spent into the above grade area and I'd bet the selling prices would be pretty close.
Particularly for commercial buildings, there's a huge amount of waste in the practice of retail stores moving into a location, tearing down an existing structure, and then building a new one of similar size just so that it better matches their "standard" store format.
i.e.: Is it really a net gain for the new Walmart to be LEED certified if they tore down a 100,000 sq. ft. structure that was less than 20 years old to build it?
A little late, but thought I might post this chart of historical CO2 levels vs. Temperature (all from proxies of course).
That graph is misleading and has been pretty thoroughly addressed here, among other places: https://skepticalscience.com/co2-higher-in-past-intermediate.htm. Short version: it doesn't matter, we still have a problem.
Interesting link. I'll study it. Btw, love that house in the intro!
Thanks, but I had nothing to do with it--it's something the FHB editors found. But I like it as well, and think the image is evocative of the climate issue.
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