> With all due respect, looking at your numbers my hunch is that you need better insulation.
With all due respect these are the kinds of "tiny" details that renewable enthusiasts conveniently forget. Yes, this person's house needs better insulation. As does everybody else's.
You can't just wave this away with "your math is wrong". These numbers reflect reality, not wishful thinking.
I wish you would expand and clarify the point you are trying to make. Currently it sounds like you are angry at a group of enthusiasts.
I think for me and the OP it’s quite clear that optimizations can be made on production and consumption side. And in their circumstances financial reality says that increasing production is much cheaper, while possibly providing extra cash that would enable investment for reducing consumption, which in turn would lead to more income.
> I wish you would expand and clarify the point you are trying to make.
The problem with people enthusiastically proposing renewables as the cheap solution to our energy needs is the thousand "little" details like the one above. Whose only mention is in the comments like "your math is wrong, invest in insulation".
No. The math isn't wrong. Bo, the consumption is correct and shouldn't "should be lower". Because it's directly indicative of the reality.
Yes, you have a couple of enthusiasts who can sink another X kiloeuro into rebuilding their house. For the absolute vast majority of users it's not a viable option.
So yes, the answer to "PV energy is almost enough in summer and not nearly enough in winter" isn't a dismissive "you're doing insulation wrong".
I think they're trying to say that insulation (and probably other factors) is not just one person's problem but an issue of a huge scale, which is true. If solar works for you, then that's great, but for a lot of people (the majority?) it wouldn't work, or at least not without spending a very large amount of money to retrofit your house for it.
I think it's a good point even if stated quite poorly.
Let me put it this way: is me having solar panels making things worse for "the majority"? If so, how?
Because it sounded like the usual trope that if a solution does not fix all problems for all humans everywhere, than it it sucks and the person doing what they can is a naive fool, if not a straight up villain.
As for cost effective - subsidies. Big fat subsidies, especially for the poor countries. There are more important things than cost effective. We're all in this together
Cost is not really a valid reason not to pursue renewable. We need to switch to renewables no matter the cost, so as many people can survive as possible, and limit mass extinctions
> Cost is not really a valid reason not to pursue renewable.
If you have a money printer in the basement or free materials and slave labour, sure. In every other case it quite simply is.
> We need to switch to renewables no matter the cost
All true, but not relevant - we live in the real world where we make practical decisions. One of the aspects of that is not spending more than you have (for example so you can still eat).
How is this a tiny detail. We live in a passivhaus. We hardly ever heat. Improving insulation of old houses is an important aspect here. Reducing energy consumption is as important as generating and storing energy.
The point is that in some situations it can be more cost effective to generate additional energy than implement energy saving measures such as insulation improvements. My house was built in the 1600's it's very difficult to insulate properly.
Real Question: I see posts like this often on HN. Why not tear down these houses and rebuild with energy efficient ones? I know... blah. blah. blah. historical this and that... but do you want to suffer from 40+C summers? This is the price of history! Think about it. Really really! Please start tearing down these horribly inefficient houses that are "historical". We already do it for office buildings!
The issue is that it's ridiculously expensive. You have to pay an inflated price for an existing, perfectly fine home. Then you have to pay to have it demolished. Then you have to pay to build a brand new home. It's going to cost >2x what the resulting home is actually worth.
When the old homes decay to the point that they need to be torn down, then they will be. But destroying perfectly good houses is just too expensive in this market.
The point is not that everyone should live in a passivhaus. The point is that better insulation can help reducing energy consumption. Not best: better. Those are two different words. No, you don't need a passivhaus, but the passivhaus example, which barely needs heating, is useful for demonstrating the efficiency of insulation.
> The point is that better insulation can help reducing energy consumption
Yes, that's a wonderful tidbit that fans love to say.
It's also about as relevant to the discussion at hand as giving tips of how not to spill your coffee on the deck to keep it dry is to a sinking boat.
You can't solve climate change with better insulation. Sorry.
Part of the problem with the discussion about climate change is that people who've never actually looked at the numbers feel the emotional need to take the position of an expert and explain what will help.
And yes, if a car is rolling down the hill at you, at some level, technically, throwing a grape at it will slow it down.
But not enough to matter.
When you take the time to put your solution in the specific context of the discussion, and take a look at how big the impact is, you realize "oh wait, no, this actually isn't a valid line of thought."
You might as well try to solve the national debt with a ten dollar bill.
You're missing way, way too many zeroes.
In order to stop climate change, we must go carbon negative. Energy reduction does not change carbon dynamic spread, and cannot solve the problem without reducing our energy spend to zero.
I enthusiastically recommend that you read some work by the academics before continuing. These are not new ideas, and they have been roundly and thoroughly debunked for decades.
It turns out that yes, we have thought of insulation. This was not a curve ball. Owens Corning has so thoroughly advertised it to us that by the time I said their name, we all shared a memory of their mascot, its song, and their theme color.
There is a reason that absolutely nobody who's got actual traction in the field is offering improved insulation as a solution.
The reason Passivhaus is a good example is simple: they claim a 90% reduction in carbon, and when they tried to get LEED certified, LEED said "actually you increase carbon, we're not certifying you."
You're listening to marketing, and trying to hold it up as engineering. Every time you attempt to google for this, please do yourself a favor, and check whether the text you're looking at is word for word identical to their marketing materials.
Try a university study. None of them say it's a benefit, and there have been tons.
Respectfully, no, weird houses that make carbon worse aren't going to fix this either. Thanks for understanding.
A lot of what you typed have nothing to do with my answer. You also seem to be making a lot of very uncharitable and unpolite assumptions about me that don't make sense at all, since I only posted one single message, so I'll assume you're under the impression that I am someone else. Sorry but I won't be dragged into an internet argument.
Seems like every time extremist solar fans try to say "I don't understand why everyone doesn't just do it my way, which doesn't work unless you engage in exotic housing outside of cities," and someone points out why that doesn't actually work, they take it like a personal attack
I appreciate that you don't see how a direct answer to your question, where you asked what you don't understand and it was spelled out for you, doesn't relate to the discussion.
I agree, your attempt to make the world's energy problems about the way you live personally in a Passivhaus doesn't relate to this discussion. That was kind of my point, as well as the point of several other people who've replied to you so far.
You might as well ask why everyone doesn't just live in an igloo. It's because they don't work in the places that most people live, like downtown. And if you try to ask the company "hey, I see that you claim you reduce carbon by 90%, why wouldn't LEED certify you, they only require 30%," the company will quickly change the topic.
I'll try it a little differently.
"If your solution doesn't work for 99.99% of humans, your solution just doesn't work."
No, I wasn't selling anything. This wasn't spam. But, you knew that.
I was making a good faith attempt to answer the question you asked.
I think what this person meant is the renewable enthusiasts treat insulation as something easily done whereas it will take 100 years to insulate the majority of houses in Europe in my view…
I know you are just illustrating an opinion and not meaning it literally, but I want to stress how ridiculous your number of 100 years is in reality.
The expected economic lifetime of a building in Germany is approximately 100 years. Which means that on average, the house will be torn down and rebuilt after at most 100 years, because additional upkeep would not make economic sense.
This means that if you do not change policy except mandating modern standards for new buildings (which is already done) and do literally jack-shit, the normal economic activity will have the problem sorted out in that timespan.
For reference: Of 22 million buildings in Germany, "only" 12.5 million are built before 1977.
The German government aims at having pretty much all buildings energetically renovated in 2050.
The biggest problem is that 1. there are many house-owners who literally do not give a shit even if they can save lots of money by an investment. Not everyone is economically minded and there is no political will (or legal basis) to force these people for their own good. And 2. for bigger apartment buildings etc. it is hard to do an invasive renovation while the units are occupied, limiting the scope of renovations to something that can be done in-place or one unit at a time or without affecting tenants.
>The expected economic lifetime of a building in Germany is approximately 100 years
Source?
Counter examples: my house is built 1908. Lots of other houses built around the same time in the area I live in. My parents live in a house from 1749. The entire village where they live is made of houses built 200+ years ago, it's written on the house in general, hence easy to check.
Hence I very much stand by my prediction it will take 100 years to isolate the vast majority of houses in Europe. Of course it's just a prediction based on my observations, I'm not an expert in the area.
Assuming an economic lifetime of 70 to 100 years for new buildings is industry practice based on standards like DIN 276. You can find those numbers (with some variation) on pretty much every web page dealing with economics of building, for example here: https://www.bauprofessor.de/wirtschaftliche-nutzungsdauer-ge...
You can also approximately extrapolate that number from the source I have given you. (Which is based on a survey by the federal government of Germany) If approximately 50-60% of houses are older than 50 years, then assuming a approximately linear to progressive attrition curve you will get a number around 100 for the average lifetime.
Of course a long tail exists, but 1. I was talking about economic costs, people might just like their houses and renovate even though it is financially not worth it, and 2. after 100 years the historical protection (Denkmalschutz) gets more and more relevant and is a whole different set of regulations.
I think you misunderstand what "economic lifetime" means here. It is mostly relevant for tax purposes.
In other words: if you build a house for $X and live in it then for tax purposes it is assumed that (on average) after a 100 years you must have been spending $X for maintenance so that you can sell the building for $X. If you have spent more money, then you can't deduct that from tax (exceptions exist).
Or in yet other words: if you don't spend anything for maintenance then after 100 years (on average) the building will be worth nothing, meaning that it will cost the same to rebuild it compared to fix it.
But since most people maintan their buildings, i.e. fix the roof when it starts leaking, fix the doors and windows when they break or are not airtight anymore etc., buildings are much older than 100 years. 100 years is the _minimum_ time before it's even worth to rebuild on average.
These maintenance tasks are exactly what this discussion is about.
You will do major work on roof or facades every 50 years or so. This is exactly the opportunity where you pretty much get insulation for free.
After 100 years the house will have been all but structurally rebuilt once, just for upkeep reasons. You perform energetic renovations together with the upkeep tasks.
And when the house is old enough, the monument protection agency will even force you to do it by that time.
> The expected economic lifetime of a building in Germany is approximately 100 years. Which means that on average, the house will be torn down and rebuilt after at most 100 years, because additional upkeep would not make economic sense.
This is just wrong. An economic lifetime of 100 years does not mean that the (on average) buildings will be torn down and rebuilt after at most 100 years.
And I have already explained why that is. Please read my post again and try to understand it.
> You will do major work on roof or facades every 50 years or so. This is exactly the opportunity where you pretty much get insulation for free.
No. This is also just wrong.
Yes, when major work on roof or facades have to be done, this is usually the best opportunity to also improve insulation. But you don't "pretty much get insulation for free". Unless you have a very uncommon definition of "pretty much for free".
Mind that I'm not saying that insulation isn't worth it or anything like that. I'm just pointing out that some parts of what you are writing are wrong. And the sources you cited are not supporting your claims. That's all.
Please don't forget that my claim is in the context of somebody else claiming that insulating all housing in Europe would at least take 100 years.
Now you are literally redefining the terms I use and then quoting them back to me to argue your new semantics, are you serious?
On average, a house is considered to last 100 years in Germany. Call it economic lifetime or whatever else you want. I still stand by that claim, as it is common knowledge. I quoted specific numbers on the housing stock which are consistent with that claim (though no proof of causation, as there are plenty of reasons why we have a lot of new stock, for example in general rising number of buildings.)
And of course the insulation is not "for free", but the additional costs are usually worth it. I also mentioned that many people decide irrationally because they do not want the work associated with planning and ordering the maintenance to be performed.
None of this matters to show that the above mentioned claim how long renovation of the current housing stock will take is completely out of the world.
Note that I am by no means a civil engineer or architect, but following the discussion and researching the topics associated with the Energiewende in the different sectors for over a decade now. I may still well be wrong in this instance. But you won't convince me of that if you try to prove me wrong on semantics and just asserting that I were intellectually unable to understand your arguments. So please also state some relevant facts and sources to support your claims if you want to try further to convince me, otherwise continuing this discussion is probably a waste of time for me as we both will probably not learn anything new. Thanks.
> But you won't convince me of that if you try to prove me wrong on semantics
> (...)
> On average, a house is considered to last 100 years in Germany.
First please define what you mean by "last" so that we share the same semantics and then provide a source on this. And if you mean that a building will have been destroyed and rebuild after 100 years on average then I doubt this claim - after making such a strong claim I think it's up to you to provide evidence.
> I quoted specific numbers on the housing stock which are consistent with that claim
Are you referring to https://www.bauprofessor.de/wirtschaftliche-nutzungsdauer-ge... ? Because if you do, then again, you misunderstand what they are talking about. Also, don't forget that average house-ages are misleading due to WW2 where a lot of old houses got destroyed. So you can't e.g. just take the average age of existing houses, that doesn't work.
> And of course the insulation is not "for free", but the additional costs are usually worth it.
Look, I agree with you - but the way you said it before is so exaggerated and easy to misunderstand that it's no wonder that you are getting these kind of responses. This is a very emotional topic and it's good to try to adjust the language accordingly.
> I also mentioned that many people decide irrationally because they do not want the work associated with planning and ordering the maintenance to be performed.
It's easy to call someone irrational - but why do you think they don't want this work to be performed. How comes? I doubt that you assume they want the planet to die, so what do you think are their reasons?
> First please define what you mean by "last" so that we share the same semantics and then provide a source on this.
Le me just try to give a definition, "lasting" for me means that you only do maintenance and rework that you would still consider the building year to remain the same after you are finished.
Also the semantics of the term "lasting" were not the issue, the issue is that you do not my sources because you find the term economic lifetime and its definition unacceptable.
Someone else in this thread posted a similar source from ourworldindata which has a bit older data but also shows the same trend.
The latter source also has a more detailed breakdown of building years. But even the former source mentions 1977 as its index year which already alleviates the external effects of WW2, people did not just live without houses for 30 years, the lost housing of WW2 was mostly rebuilt in the 50s.
Also, I do think that your claim is not valid. I do understand that the source I gave for economic lifetime, and also the norm I quoted is acting with fictions required for taxes and accounting reasons. The thing is: These fictions are intended to reflect reality. So I don't get why you are so hung up on where these calculation models originate, as they are specifically designed to reflect reality. If they were outlandish, especially when lifetimes on average are longer, these calculation models would absolutely be changed because then the state earns more money due to lower depreciation. If it was the other way around, the calculation model would be challenged in court.
Of course there is no natural law that a house collapses after 100 years. But not only in architecture, in all of engineering, it usually does not make sense to design for an infinite lifetime. If you double the lifetime of anything, it will cost a lot more money. Why would you spend more money today to build a house with better materials, when you don't even live to see the rewards in the form of lower maintenance and renovation costs in a 100 years. By extension this applies for the amount of money you want to spend in maintenance, at least for natural persons. In many situation it makes sense to simply use up the bound capital.
Now this leads to the following:
> It's easy to call someone irrational - but why do you think they don't want this work to be performed. How comes? I doubt that you assume they want the planet to die, so what do you think are their reasons?
As an anecdote for illustration, my grandparents still heat with oil, but the heater soon needs to be replaced. My grandparents are absolutely stubborn in that they want to replace it with a completely new oil-based heater. The literally only reason is: They are old and don't want to try out something new, even if it is functionally exactly the same (like a wood pellet heater). I literally offered them to pay 100% of the new heating system (reversible heat-pump because heat is one of the primary killers of elderly people and I would like my grand-parents to be around a bit longer...) after they bought heating oil on the ATH this spring and they still disagree. There is literally no economic incentive of looking the gift horse in the mouth, and they are unable to offer any other rational explanation.
You may also skimp on maintenance because you think "I am going to die soon anyways". Or people are planning to be living in a large 200 square-meter mansion with 3 stories until they are 90 when in reality they sell the house at 60 and suffer the loss of value when re-selling due to insufficient maintenance.
And some people just want to live in their house and don't give any thought to it until there is an emergency. Then people will have expensive repairs and still won't think twice about changing their behavior.
Some small house owners skimp on maintenance because they bought their houses as an "investment", and they are dependent on rent income to reliably subsidize their life. Even when the income could be higher in the future with some investments and quickly ROI, they won't accept saving up for it and taking on the economic risk.
Even for institutional housing owners it makes sense to tear down units eventually, even if it is just to get rid of the long-term tenants who make larger renovations annoying to impossible.
There is a lot of small house-owners and in general, most people are just really bad at basic accounting.
This is also a big reason why the housing market in general is such a pain in the ass.
> But even the former source mentions 1977 as its index year which already alleviates the external effects of WW2, people did not just live without houses for 30 years, the lost housing of WW2 was mostly rebuilt in the 50s.
It does not sufficiently alleviate the effects of WW2 and other developments.
For instance, the population got reduced to 82% due to WW2 [1].
Also, living space per person has increased a lot over time. I can't find a source for 1945, but here is one from 1971 to 2014. The number of squaremeters per person has almost doubled during that time. [2]
So no, people didn't live without houses for 30 years. But they needed/used way fewer houses overall.
> Also, I do think that your claim is not valid. I do understand that the source I gave for economic lifetime, and also the norm I quoted is acting with fictions required for taxes and accounting reasons. The thing is: These fictions are intended to reflect reality. So I don't get why you are so hung up on where these calculation models originate, as they are specifically designed to reflect reality.
You are misinterpreting them. They don't literally say "houses are worseless on average after a 100 years". They say "houses are worseless on average after a 100 years without doing anything to increase their value". And this is certaily more or less accurate. However, most people don't just let their buildings rot. Some do, but most don't that's why buildings are on average not being rebuilt after a 100 years.
> Why would you spend more money today to build a house with better materials, when you don't even live to see the rewards in the form of lower maintenance and renovation costs in a 100 years.
I find it a bit offtopic, but a very common example is that parents want their children to inherit it so that they don't have to worry about rent or can rent it out for some extra income. Other examples include people who don't necessarily want to stay in the house forever but want to increase the value to sell it later to a higher price. Some people also just enjoy building something that lasts (I am one of those). I think you can agree with that, no?
> My grandparents are absolutely stubborn in that they want to replace it with a completely new oil-based heater. The literally only reason is: They are old and don't want to try out something new, even if it is functionally exactly the same (like a wood pellet heater). (...) and they are unable to offer any other rational explanation.
First, let me say that I understand how you feel about that. I know the situation and sometimes it pains me to see what people do. I would have adviced the same as you. However, without knowing the situation, I think that sometimes in these situations the problem is safety concerns.
The fact that they are unable to "offer any other rational explanation" really makes me think that there is quite the chance that they do have a reason and they are just tired of providing it. If I had to make a bet, I would say they had some bad experience with modern technology in one way or the other. And they maybe also know a time where the winters were cold and heating didn't work. They do not understand heat pumps (not even I fully do) and they are afraid that when something stops working, they are helpless. For them, it feels like a total lack of control over something that is crucial to their life. But would you accept that answer? Probably not. Maybe they already hinted at it - try to remember if they did that and if you properly acknowledged their fears. With oil, not only do they use a technology that has worked for a long time and is much more well understood by them - it actually also makes them more independent of restrictions to power/heating compared to other solutions - at least as long as they have a full tank.
Unfortunately they could very well not be irrational but very rational when considering their situation. Is the decision good? No, I don't think so. But it is not irrational.
Of course, maybe I'm totally wrong. But it wouldn't be the first time that I see a conflict like you describe.
In the end, let me give you some advice to your situation. If you think that it could really be feeling of control and safety that makes them stay with oil, then how about offering them to install an aircon? Aircons are heat pumps as well, and very efficient ones as well (usually more efficient than air/water heatpumps). They can keep their oil, but the aircon might make it able to reduce the oil consumption by a huge chunk, depending on the circumstances. It doesn't cost too much and you even get BAFA Förderung. And on top of that, you can use it to cool/dehumidify of course - heatstroke is also a common reason for elders to end up in hospital. That solution is what I would try in your situation.
> And some people just want to live in their house and don't give any thought to it until there is an emergency. Then people will have expensive repairs and still won't think twice about changing their behavior.
This is not irrational, only lazy.
Irrational means to do something even though you know it's wrong. E.g. out of a mood.
> It does not sufficiently alleviate the effects of WW2 and other developments.
Remember, we are still talking about the claim that renovation of the building stock takes approximately 100 years.
It does not matter whether we are building more because people need more space, or because houses are actually replaced. All that matters is that the percentage of the building stock built under modern energetic regulations rises sufficiently fast.
This is why this discussion is so frustrating for me. It's all about semantics that don't matter, when my point was actually just disproving a point I thought to be ridiculous (which with the new research I did for my rebuttals was actually sort of disproved, as Germany seems to be really good at renovating the building stock compared to e.g. Eastern Europe), which is also why this will probably be my last post in this thread.
> You are misinterpreting them. They don't literally say "houses are worseless on average after a 100 years". They say "houses are worseless on average after a 100 years without doing anything to increase their value". And this is certaily more or less accurate.
You seem really hung up on the topic of depreciation accounting (AfA) and don't seem to get my point. Depreciation is regulated and does not exist in a vacuum.
Depreciation is a legal fiction to model the reduction in value of assets in such a way that it is easy to calculate, but also close to the actual value that would be fetched on the market due to the depreciation.
You are essentially claiming several things with your argument: 1. depreciation is not correlated with actual value loss, and therefore 2. the economic lifetime model used to calculate depreciation does not correlate with actual use lifetime.
The first is correct: Renovation expenses can be used to raise the book value of the asset making them balance-neutral.
The second is not and especially does not follow from the first for the reason that I told you, the lifetime model used in depreciation calculation is based on the observed lifetimes in reality. There is also feedback in the other direction as engineering decisions are taken based on the best practices in economic lifetimes, which is why I cited the relevant DIN norm for cost calculation for builders in my first post.
> That solution is what I would try in your situation.
Thanks for your advice. But I already tried that. And it's pretty funny that you literally try to explain the mentality of my grandma to me. But what do I know it's only my grandma.
Let's just let the topic rest, I do not really care about this discussion anymore.
> Assuming an economic lifetime of 70 to 100 years for new buildings is industry practice based on standards like DIN 276.
Sure, but that wasn't the standard 100 years ago. There are plenty of existing houses that are 100+ years old that will continue to stand for at least another 100 years.
Your parents house was built in 1749. Do they pay the equivalent carbon tax to own a house like this? Unless it has been hyper-modernized, but the exterior remains old/ancient, I struggle to understand or support your argument.
More brutally: If you parents want to live in a house from 1749, should 1.5 billion people (probably more!) in South Asia be forced to live in unsustainable conditions (much high average annual temperatures) for the "history" of your parents' house? Absolutely not.
In contrast, if you support massive gov't subsidies and personal taxes to pay for the upgrade of these homes to 21st century energy standards, then... sure, no problem, they can live in a home from 3000 BC!
A lot of people in Eastern Europe live in apartments and houses that can be insulated extremely cheap. There are even EU or government programs that make it affordable.
It's not really "extremely cheap" and probably only refers to covering old buildings with external insulation.
Most of the Soviet-era panel apartment blocks (https://en.wikipedia.org/wiki/Panel_building) have extremely shitty internal insulation, too. So you end up heating your neighbors, the street, the elevator shafts, stairwells etc.
You can't really fix that without extremely costly renovations.
Khrusschchyovkas (https://en.wikipedia.org/wiki/Khrushchyovka) are marginally better due to materials used, but they are 50 years past their demolition date by now, and will be also very expensive to retrofit.
There is also an insane number of new construction in the past 30 years. Perhaps for the in-EU Eastern European countries regulations and standards work. Everywhere else it's "whatever we build, as cheaply as possible"
I think having some insulation is better than having none. But yeah, if you want to do it properly, it would cost a lot more.
As for heating your neighbours, a lot of cities have city heating and is paid depending on how many people live in the apartment, so you don't care that much about it. Of course, some folks have gas boilers in their apartment (like me) but it won't make sense financially to insulate the inner walls.
I think it's the same for new buildings here too, if not worse. A lot of regulations aren't actually respected and because a lot of builders left for WE, there's a huge problem with finding skilled workers.
What I mean with legal basis is that the laws do not exist yet.
The constitution would allow these laws, even to the point of expropriation. But as long as the laws do not exist there is no legal basis to act on.
In case of conflict, there are some court rulings already, for example the highest court recently ruled that you may infringe on the neighbors property, if you need to insulate your walls in such a way that the thicker walls would then be on the neighbours property.
Much of eastern Europe, so not particularly rich or well run countries, went from zero (due to cheap Russian gas in Warsaw pact) to ~everything insulated (because trying to cut dependency on a mortal enemy) in less than two decades.
The EU paid for lots of insulation here in Bulgaria. Mostly blocks of flats, of course. They were ugly and really needed it. Hope you guys enter the union soon
Except the large majority of buildings are not going to last anywhere close to 100 years, and they will be very likely be replaced with better buildings long before that.
And most of the buildings that instead have a lifespan beyond 2122 are historical buildings built with very thick walls and they don't need insulation work beyond replacing windows.
There are many statistics on building lifecycle that you can easily find on the Internet.
So such estimation is really not grounded in reality.
> Except the large majority of buildings are not going to last anywhere close to 100 years, and they will be very likely be replaced with better buildings long before that.
We need a quote on that. And no, "bulidings last on average 100 years without doing anything to them" is not it.
"Replaced with better buildings" inevitably means "displacing large swaths of population". Because you can't just wave a magic wand and replace houses. For the past 4 years I've lived in a district built in th 60s. So, 60 years ago. If you're telling me that those dozens of building with hundreds of people living in them will be just up and replaced, you're delusional.
You can usually improve insulation by popping down to the local DIY store and buying some rolls for your loft making a big difference.
Of course you can only do that once. And if you’re a landlord why would you pay your money to insulate when you wont save any money as your tenants are the ones paying the bills.
Have you ever heard of mould? Moisture in the walls? Caused by shifting dew points. Your "just pop down to the hardware store" DIY insulation will do a lot of damage.
In some countries, you can't rent out homes that fall below a certain standard for insulation, and the efficiency is rated as part of every property sale, which internalises the cost savings and makes it worthwile.
> With all due respect these are the kinds of "tiny" details that renewable enthusiasts conveniently forget.
I mean generally it is well known that you cannot just put a lot of PV/Wind and things will work. A smart grid is needed, buffers and ideally great insulation although that is arguably important for every form of energy. Also at-home PV setups are meant to earn money/offset the energy bill. Autonomous energy supply is an after-thought that is interesting enough but has obviously not been possible with any other energy source before actually.
Well yes, but generally renewable enthusiasts are also saying "we need to improve our housing stock". That's another of the opportunities to improve people's lives that will come through necessary change.
Housing energy models are well established - things like PHPP, which though a bit of a dog to use is well validated and cheap. Low and negative carbon techniques are also available - things like mycelium insulation, which notionally outperforms EPS (and even that pays for itself from a carbon perspective very quickly if used properly).
You make some good points in the middle of the edgy writing, but how do you think people get to the point of proving out new technology?
You'd be shouting at the magic black gold people too back in the day. How would it light people's houses and require a full grid installation, and fires and blackouts, when candles already fix the real world problem.
With all due respect these are the kinds of "tiny" details that renewable enthusiasts conveniently forget. Yes, this person's house needs better insulation. As does everybody else's.
You can't just wave this away with "your math is wrong". These numbers reflect reality, not wishful thinking.