Why Don’t Green Buildings Live Up to Hype on Energy Efficiency?
e360.yale.edu
e360.yale.edu
Triple pane glass? Check. Green materials? Check. High efficiency heat pump? Check. Etc. Etc.
If you check as many boxes as possible your building is labeled green and everyone applauds.
The real way to measure this would be energy used to construct the building, factoring in supply chain and then ongoing energy usage per square foot. You would also need to factor in what the building was being used for and perhaps, depending on the building, the output and production of said building.
All of this is to say, it is complicated. I suspect many modern buildings are space inefficient leading to less production per square foot. Therefore even if it is a green building that is well designed there is a certain level of inefficiency in that it is a larger than needed building that has to be lit, heated, cooled, etc.
And to clarify, I don’t believe the “check boxes” are completely meaningless, rather the issue is that it provides room for gaming of the system to achieve a rating. This of course will probably always occur to some extent.
Thank you for edifying me.
What is objectively true vs. what is subjectively understood and expected from "Green" as an ideology, are generation two completely different things.
Expectations are unreasonable in the latter. So that causes the judgement of "success" to be unreasonable.
Most people do not have an objective understand or perspective of what being Green under LEED would mean.
Most people think and act as though you can throw up a few solar panels and then run an iron blast furnace with the Green energy. The numbers simply don't work. Most people do not understand how much energy is required to provide their current lifestyle!
The level innumeracy and its universality of that innumeracy is that Epic Fail.
It's the worst in places that are the most religiously strident places like California. In general, you'd need land for solar panels equivalent to your entire neighborhood to merely duplicate and provide your current energy use just from your own home. And that doesn't even cover EVs being charged!
So how much did that house cost you? And now you need 10x that much land just to be Green? And what about the energy inputs to build and keep the Grid going so you can use cheap land for that? It's a lot more than anyone typically is aware of! Try 20x-500x depending on specifics of things like thermodynamic efficiency and resulting impact on supply chains!
And a 10x-20x puts you into fossil fuel, nuclear power territory being optimal.
That's false because it is based on the assumption that you should convert the input BTUs of your natural gas heater directly to hypothetical kWH consumed if substituted with electricity, which is silly because if you are trying to generate 100% of your energy consumption locally (a goal of questionable value itself), you would change your mechanical systems to electrical ones that are 3-5x more efficient at delivering space heating than natural gas furnaces.
The most efficient nat gas furnaces are 96% efficient, but heat pumps routinely achieve 300-400% efficiency. That works out to far lower energy input for space heating.
A far more sensible approach to local electricity generation is to move to more efficient building and mechanical systems and only generate enough electricity via solar+storage to power critical loads during a grid outage.
> And that doesn't even cover EVs being charged!
Given, the average American commute distance, EVs will always be a grid coupled technology due to their huge energy requirements. This is a good thing because they will needed to provide buffers for grid and home resiliency to less predictable power supply and demand patterns.
Which people?
> It's the worst in places that are the most religiously strident places like California.
Like the prior quote, this characterizes and denigrates a different set of people. It tells us nothing but your willingness to insult and ignore them. Let's stop dismissing people (probably not coincidentally, a certain political grouping being dismissed using the language common to another political grouping) and use genuine curiosity about the world - and other people - to further our knowledge. Maybe some people in CA know something important; maybe they should be treated with respect and listened to, being other genuine people.
Math please. A 100 square foot solar panel would generate around 150 kWh per month given around 5 hours of sunlight a day. The average household uses under 1000 kWh per month. So you'd need around 700 sqft of solar panels to cover that which fits on the roof of a single story house easily.
edit: And plenty of people sell electricity back to the grid on average while having rooftop solar panels.
Electrowinning iron takes about 4kwh per kg. So maybe $200/ton worth of electricity.
The LEEDv4 marketing materials don't have the tone I would expect if LEED has actually evolved into something more useful than a greenwashing marketing program. Maybe they've improved it but I would need to have some third party say "earlier versions of LEED didn't actually mean any of the things you would expect, and LEEDv4 has corrected that in a meaningful way."
Society is extremely inefficient
it seems to me that we could still provide more with less (resources and time), without going in analysis paralysis
Well, western society didn't adopted central planning, in a good part as central planning's failure to meet society's needs.
Anyway, I don't think it's fair to criticize these efforts by depicting them as some sort of failure or the result of incompetence or shortsightedness. We have to have some humility when discussing these topics specially if they are from a field where we have no insight at all. In this case, we should keep inind that valuing energy efficiency and externalities is something that's extremely novel where society as a whole is just starting to take it's first steps. It's quite literally a highly transformative change that involves changes in all steps of an entire industry, including in building regulation and even urban planning. Change is happening as we speak, but what you are looking at, and criticizing, is society's first step in a much needed direction.
I think it's fair to at least voice it out, I'm just trying to dig out what are the real reasons and potential new ideas.
In the case of the building where I lived, they were required to retain the original windows for historicity: rickety, drafty, single-pane affairs that leaked prodigious quantities of heat. These windows were very large and the ceilings high, so in winter you essentially needed to run the heater non-stop. To offset that, they unnecessarily and often quite uselessly over-engineered other parts of the building construction for green-ness, which I presume helped with whatever scoring system made the building "green". None of which changed the fact that the building fundamentally leaked energy like a sieve.
It was always a mystery to me how they managed to LEED certify one of the most poorly insulated buildings in which I've ever lived. Nothing else you do to a building should be able to offset that fact.
The process you’re describing is called lifecycle analysis and it’s complicated.
The greenest building is something like a giant tent, high on total resource efficiency but lower on comfort.
There are tradeoffs to consider and a lot of them are lifestyle choices, like wearing a sweater indoors.
"...students and staff told the Guardian that the plant’s wood storage area is now being used to store Christmas decorations."
https://www.theguardian.com/environment/2016/mar/03/uea-aban...
"Once the decision was taken, the estates team appear to have been driven by a need to meet a timescale to qualify for a DEFRA grant.
The estates team seem to have struggled to find a proven technology at scale, but were introduced to Refgas, who convinced them that their design would work.
With time pressing and due diligence on Refgas incomplete, the standard procurement and contracting processes were bypassed."
https://www.edp24.co.uk/news/confidential-report-reveals-str...
[0] https://en.wikipedia.org/wiki/Cogeneration
[1] https://www.bioenergy-news.com/news/university-of-east-angli...
A large part of a building's NABERS rating had nothing to do with how much energy the building consumed at all, but whether or not it implemented certain "green" technologies.
As someone who had worked in the insulation industry for 25+ years prior to this, it used to shit him to no end.
After a howl of protest, they went in and removed the flow restrictors. Now the shower heads spout a satisfying amount of water and the sink taps work the way they should and life is good. Probably makes very little difference in the overall "greenness" of the building but these are just examples that I know of.
Good green building design isn't entirely rocket science. The biggest cost in terms of energy is heating and cooling. Depending on your location the sun is either your enemy most of the time, or only for a few months.
Either way, you need good thermal mass, low U walls, low U windows and air control This will get you 90% of the way to low energy, the last 10-20% is a lot harder to get.
Agreed, I think the Pretty Good House concept sums it up quite well without going too deep into building science: https://www.prettygoodhouse.org/the-whole-shebang-in-one-rea...
Green building design is normally ~90% conservation outlined in the link above and 10% green energy sourcing
Most of the problems could be traced to simplified models they claim, yet the two they actually mention in detail clearly did not. And they make no attempt to quantify the contribution (in terms of cost Vs energy waste) of the ones that do.
It seems highly unlikely that they'll rival having your heat on too high and the windows open to vent the heat.
In particular, a school in a valley in the UK having its lights on doesn't on really seem like a big deal as long as they're using LED lights. Attempting to harness natural light in this type of building sounds like a feel-good notion that can't possibly compete with decent led lighting run from a renewable grid.
I live in a house with huge southeastern window... and when there's occassional clear winter morning, the light and later the warmth, that's...glorious! No idea how could I replicate that with LEDs, would be probably pretty expensive.
If it was as simple as light exposure, leds on glasses would be an easy cheap fix - wear light therapy glasses x minutes a day while you work or listen to podcasts, etc.
Plants store their solar energy in a hydrogen-carbon bond for storage. To compare a plant with a solar panel and LED you need to also include the storage technology, which is usually batteries. Because plants do not as a rule glow brightly, a more apt comparison would involve, say, a locomotion system. Comparing the efficiency of, perhaps, a car that drives at night powered by a solar/battery system vs. a plant/combustion system. It would be an interesting experiement.
And yes, I know the dye doesn't absorb green. It's still a green dye; last I checked we name dyes by their reflected color.
You meant a "green, light-absorbing dye" (using hyphens to make the distinction clearer), the previous poster understood "a green-light absorbing dye".
Most indoor lighting is below 1000 lux. Bright daylight without direct sun is 10000 lux. There's no comparison between proper daylighting and almost any reasonable amount of indoor lighting. This is why it's very difficult to see things even on a very high luminance screen like a Macbook Pro outdoors during daylight.
I didn't mean compete in terms of max lux output, though if they actually wanted to do that for whatever odd reason (film studio? indoor weed farming?), the basic tech probably could as well.
I meant effective task lighting for multiple people and multiple tasks across seasons in a large building with multiple very similar large rooms that have windows in different places but usually along one wall only (in a valley, in a cloudy country relatively far from the equator).
Which on the face of it, seems totally absurd. Things such as Night School, and schools/offices near the poles for example, exist. Is there something more specific that you're actually saying?
Especially children need significant time spent in bright daylight in order to develop normally. It's not beyond our technology, but nobody actually does it.
Maybe that's just me, but natural light is way better for my mental health than artificial light. Being forced to depend on artificial light makes me feel like I'm in a basement, which I don't like at all.
How much energy is used to build and maintain the building.
Can the building function as a building people want to use - if just sits empty its a huge waste of energy. Removing all the windows would help but wouldn't be very appealing.
And lastly ventilation is probably of of the most tricky, it's very easy to create an energy efficient sealed box, but how do you create a healthy environment - older buildings are drafty but it comes with health benefits and keeps the building dry by allowing moisture to escape. The answer is normally a complex HVAC system but that then uses power and requires maintenance.
ASHRAE 62.1 and 62.2, "Ventilation for Acceptable Indoor Air Quality":
* https://www.ashrae.org/technical-resources/bookstore/standar...
> The answer is normally a complex HVAC system but that then uses power and requires maintenance.
> older buildings are drafty but it comes with health benefits and keeps the building dry by allowing moisture to escape.
Drafty buildings are bad. The air comes in through random cracks and crevices, which may have mold and which also allow bugs and rodents to enter. The rodents may leave droppings, which the flowing draft may then pick up particles from. There are no health benefits to that.
> The answer is normally a complex HVAC system but that then uses power and requires maintenance.
The drafty house you laud above will also use power: in the winter air that was heated will leak out, and the cold air that comes in will have to be brought up to temperature; in the summer the cooled air will escape and the hot (and perhaps humid) air will then need to dealt with to make the building comfortable. And that doesn't include dealing things in the air like dust and pollen (plus the above mentioned critters).
Or you can install some ducting to remove stale air from the house (esp. bathrooms and kitchens), and introduce fresh air (esp. to bedrooms) that is first filtered (MERV 13+) and then tempered via an ERV/HRV core so there's a minimum of re-conditioning needed. The main source of maintenance is the changing of the filter(s). And running an ERV/HRV will use less energy (W or BTU) than re-conditioning the leaky air.
This is a solved problem: build tight, ventilate right.
After air tightness throw on some insulation (while reducing thermal bridging) and you can have a house that uses minimal energy in dealing with environmentals. You just have to make the effort up-front when designing it (or when doing a renovation/retrofit).
* https://www.greenbuildingadvisor.com/article/understanding-f...
* http://dx.doi.org/10.3390/ijerph120708448
* https://www.researchgate.net/figure/Mean-PM-25-removal-effic...
Just make sure your system can handle whatever MERV you go with (higher = more back pressure that needs to be designed for).
* https://www.zehnderamerica.com/our_products/comfowell-silenc...
Which allow MERV 16 and even carbon filters:
* https://www.zehnderamerica.com/product-category/comfowell/
Mandating (whole house) dehumidifiers in building codes may help with that if air tightness is also mandated.
https://www.kane.co.uk/knowledge-centre/what-are-safe-levels...
I’m horrified to think of all the poor people in these programs that are probably feeling bad but have slightly better energy bills. Good health is the most important quality we have. There need to be energy conserving air exchangers put in with each tight house made. That’s the best of both worlds.
Airborne contagions do not spread from bringing in outside air and tempering it via an HRV/ERV. The risks rise when you do not bring in fresh air but rather recirculate indoor air, but these can be reduced by using MERV 13+ filters:
E.g. a cheap addition to existing installations: aircode.se
Limited but sane research from around 2013(?) points to even cheaper options of ventilation treatment.
That is a link to only one of their articles. Generally pretty buildings with lots of glass are inefficient (glass has a r value of about 2). Buildings that look like windowless Boxes with no windows can have an r value up to infinity. The easiest way to make a "green building" that has glass walls is to compare it to extremely inefficient buildings in the prebuild analyses.
The perfect wall (perfect order of exterior wall control layers) makes for highly energy efficient buildings. https://www.buildingscience.com/documents/insights/bsi-001-t...
Fun stuff
Designers wanted to show off, sought the maximum possible savings under the most optimistic cases, and just couldn't stick to fundamentals, nor a good study of the conditions at the site.
Something designed with smarts, instead of 'to be smart' in the know it all sense might have met expectations. Though just like machine learning can produce solutions that tear through the test cases it's given, there are probably factors like acoustic isolation that get overlooked by the quest for maximums outside of a wholistic set of goals.
This model-reality gap in discussing energy and resource efficiency has long been an issue with all sorts of things, from toilets to materials to washing machines and so forth. There's some prototypical lab schema that's used to evaluate efficiency (in energy or other resources) that fails to take into account real-world conditions, and once it's put in those real-world conditions the efficiency breaks down.
We live in what might be considered a green home in some ways, and try to be sustainable, but I do think there's lots of limits to the scenarios that are used to develop them. I suppose in a general sense this can be extended even further as one example of model-reality discrepancy with all sorts of things we use.
The other thing this article maybe misses is that even in buildings that aren't trying to be green, or are, but with reference to non-green elements. I've gone into new buildings of different types, and when there's elements of the building that are relatively specific to that building (i.e., the design of the building is unique), there's all sorts of problems that arise due to discrepancies between what the designers had in mind and reality. One building I'm familiar with had certain design elements for aesthetic and practical reasons, but ended up creating huge sound problems; another one was done for aesthetic and other reasons but had a problem that was obvious in hindsight, but led to critical facilities being unused because people shunned it until it was rectified.
This isn't necessarily a criticism of the article but I think it's important to keep in mind a lot of these arguments aren't unique to "green" goals or buildings per se.
I’m all for posting actual results to an online (and public) database. I’m opposed to projects who don’t do that having an arbitrary three week delay in planning permissions. (If you can safely cut three weeks from some projects at the developer’s option, either you’re cutting corners on those projects or needlessly delaying the others.)
People boarding airplanes in the priority lane don’t get to board faster because there is a redundant wait applied for everyone that can be removed for prio boarders. You just let prio borders bypass the queue.
These standards, however should be updated to consider occupant load and ongoing monitoring of energy consumption in these structures.
Although approaches like these if done well are a huge improvement for a building's occupants (in comfort and efficiency), they are of still of limited global impact because they are optional.
Going forward, to have any hope of impact on climate change the best of these approaches, from architectural and system design to construction, needs to be put into the building codes. Relying on the Prius (or nowadays Tesla) effect is not enough.
That said, demand for increased savings/efficiency and comfort must be induced in the population via incentives and via the general discourse, and not just be part of an expensive optional green building certification pursued by enthusiasts.
I assume they were actually saving energy, but who knows?
Low power bulbs were one example of this, some models taking minutes to reach full brightness, nowadays led bulbs do well, I gladly use them.
Smart cooling in some office buildings do stupid crap like allow you only plus or minus two degrees of freedom on the placebo thermostat, or disable the air conditioning of the entire open space as soon as a small window is opened (of which the space had 20, so it was inevitable). Supposedly the system cooled the walls rather than circulated air... Summer sweat doesn't go away fast. But it's okay, the building's efficient and green on paper.
Once color temp became a consideration with CFL, two bad things happened: (1) they used cool white, which doesn't feel cozy but will feel dim if it's dim, and (2) they tried to do "lumen for lumen" replacement (using those equivalency guides) which meant their already dim house now looked wrong.
Whereas if you swap for CFL (or these days LED, which work way better) and just aim to halve your wattage...you still end up putting down about 3 times as much light which just plain looks nicer unless you're specifically aiming for mood lighting - which most people aren't, the options just sucked before hand (I have wall sconces for atmosphere setting lights, overhead is all neutral/daylight color).
Super sealed and well insulated walls are great! but bugs and things get in, can't get out, and you have biological processes (rot, mold) that go on from there. Walls with poor seals on the outside don't collect crap, what crawls in finds nothing to eat, and crawls out.
The inside can be better sealed but should it be? Fresh air is worth a lot; and while your air quality won't be better than outdoors; it won't stay worse for very long either.
Digging into a hillside for at least one wall of the house gives you opportunity to use a large volume of earth as a heat sink. I also gives you the opportunity to deal with moisture issues and drainage problems, everything has trade offs.
This is usually applied to small buildings but much of it scales up. New York's use of radiators to provide heating and air circulation is underappreciated genius.
Tangentially: Why don't buildings replace interior lighting with sunlight collectors and mirror systems (or fiber optics?) directing the free, renewable exterior light to where it's needed? Too expensive to implement? Yes, you'd need electrically powered lights to supplement it, but you would eliminate energy consumption for lighting when there is sunlight.
Tip: Just don't turn on the lights during the day. It's a bit dimmer, but far more peaceful and relaxing, and the sunlight through the window is enough (especially when looking at an illuminated computer screen) - depending on the room, of course.
Example: I always get 2 or more times uses out of every polythene shopping bag that I get my hands on. At least once for carrying groceries, once for carrying trash, and maybe once or twice more for storage.
If everyone did that, the demand and production of polythene bags would go down by at least half. This is something almost every household in a 3rd world country do. But almost nobody does that in a first world country- instead they waste resources on green buildings and such.
Bags cost a few cents each. I spend $100 per month on natural gas to heat a poorly insulated apartment during the winter.
"How California became far more energy-efficient than the rest of the country" [2019] https://www.vox.com/energy-and-environment/2019/5/31/1864690...
TLDR: California Energy Commission's performance standards, which automatically improve over time at predictable rate, instead of administrivia of targets, specifics, picking winners & losers.
More background:
"Climate change policy can be overwhelming. Here’s a guide to the policies that work." [2018] https://www.vox.com/energy-and-environment/2018/11/16/180963...