With all due respect, looking at your numbers my hunch is that you need better insulation.
I know a person who has about 10kWp installed on a passivhaus here in latitude 59N and says that having a heat pump is overkill for them.
I know a person who has about 10kWp installed on a passivhaus here in latitude 59N and says that having a heat pump is overkill for them.
The parameters widely differ between country and city: In the country, you usually have space (but lack money), in the city, you lack space but can often work with a pretty good income (= build a new, energy optimized house).
Every house is different. If I build a new house today, of course this would look different.
How big is the house?
.. and this was quite thoroughly calculated. I can tear down the house and build a new one, but apart from the waste of resources - building a new one will also cost minimum €200k - so I thought, why not 'oversize' PV, if it only costs €100k and can heat the house without improving on insulation?
To emphasize, this conclusion will likely not apply to the majority of people (especially here on HN) because as many have said here, parameters and contexts differ widely.
I'd have guessed that 200k to rip it down & build a new house that has great insulation - or even to just retrofit insulation and other upgrades to the existing building - would be expected to last longer before costing the same amount against to replace (and/or pricey maintenance/insurance of the more expensive PV, aircon etc.). And might therefore work out cheaper when looked at as a 50 year question rather than 1 year one?
I don't presume to know more than you, not only don't I know about your specific situation I also know very little about these subjects generally, I'm just curious.
.. it was mentioned somewhere here, too: For some, the best solution will be to focus on reducing energy consumption; for other, the better option will be to focus on increasing local energy production. And a combination of both might be best for most.
Now, there are all kinds of solutions and they all have caveats. As someone said here, old houses are build so that walls are semi-permeble, meaning that heat constantly wanders to the outside. That also means that the dew point is pretty far towards the outside in winter - water can get out of the house. If you insulate the inner wall, the dew point will move more towards the inside, meaning your walls will get wet and water will take longer to move outside. If you insulate the outside, water cannot get out at all - you must find another solution to get the moisture out of the house. It gets more complicated the more you dive into this topic.
Hence, I still do not understand the logic why isolating only a subset of walls instead of all of them would be a problem.
As I said, I had an energy efficiency specialist at my home which said that isolating 3 walls would be 75% as efficient as isolating 4 and totally recommended. So far, I have not seen any solid logic supporting the fact that isolating only 3 walls instead of 4 would *increase* the risk of mold compared to either, 4-walls all insulated, or, zero walls insulated.
As the house cools at the end of the day the uninsulated wall will be colder than the other walls and if it's below the dew point condensation will form on it. If the temperature differential is high enough in comparison to difference in insulation between the walls then enough water will leave the air to keep the dew point below the temperature of the insulated walls and so that one wall will collect the majority of moisture (at 30C a meter cubed of saturated air carries about 30mls of water so yes condensation on a surface can heavily impact humidity). Once a wall becomes moist it will still acumulate water if it's below the dew point.
You likely will have seen real life examples of this when you look at single pane windows in otherwise insulated houses and seen them fog up/ have condensate form on them while the walls around them remain dry (if you haven't seen this but have been to houses with single pane glass in your area then condensation won't be an issue where you live).
As to your 75% efficiency point it will in fact have a lower efficiency as heat transfer increases with temperature differential. Since the room has a higher temperature differential with the outside the less insulated wall will be faster at transfering heat.
That is not to say that insulating 3 walls is a bad idea, it will almost certainly improve a rooms U value, but the worse the insulation on the remaining original wall, ceiling, and floor the less difference the 3 walls will make to the rooms U value and thus how quickly the room transfers heat.
Warm/er air can hold more moisture than cold/cooler air. If part of the house is warm, and you happen to cook and/or shower in it, it will have a high moisture content.
But water vapour diffuses through-out an enclosure. So that water in a gaseous phase will equally spread everywhere (eventually).
When it reaches the uninsulated part/s of the structure, the air is colder and so can't hold as much moisture leading to condensation. Get lots of condensation, and you have an environment that is suitable for mold growth (which can then release spores in the air and mess up indoor air quality (IQA)). Not to mention that water is a universal solvent, and so will turn your structure (stone, masonry, concrete, wood) to mush over time.
The place of condensation will most likely be a surface that is a large temperature change: so in the winter your inside is warm, and your uninsulated outside walls are cold.
Today, it's generally solved by having an airtight sheet (plastic) between the insulation and the inner wall. Sometimes placed inside the insulation. This ensures a temperature gradient that will not cause condensation inside the house.
You'll generally put a sheet that's porous but not airtight outside the insulation, to reduce heat loss due to convection and also provide an extra layer of defense against moisture damage due to wind-blown rain.
This technique necessitates good ventilation (often powered) if it's used throughout the entire house. This is to avoid saturating the inside air with humidity due to breathing and other activity, itself leading to the condensation you're trying to avoid. It can sometimes be just on e.g. floors and ceilings. Then, the rest of the structure might still be leaky enough that mostly passive ventilation will do the trick.
Older houses handle the problem by just being so leaky that condensation won't be a problem.
That said, insulation is still the right answer, but it ain't cheap. OP should probably tear down that beautiful old house for something more modern.
Hotter air has more energy and thus will naturally "flow" towards cooler areas with less energy until equilibrium is reached.
In this example, the higher temperature air holds more moisture. That moisture will be carried along and dispersed towards the cooler wall, where it could condensate.
But a wall will stop condensating water when reaching a certain degree of humidity. So I’m not entirely convinced one can simply divide the amount of humidity in the air by the amount of uninsulated walls (or sqm).
The air will not have more moisture, but rather all the moisture problems will be towards/on the uninsulated wall.
> But a wall will stop condensating water when reaching a certain degree of humidity. So I’m not entirely convinced one can simply divide the amount of humidity in the air by the amount of uninsulated walls (or sqm).
Condensation will never stop on a cold wall until all the moisture in the air is removed. If you boil a pot of water the air will fill with moisture, and the entire house will have a high humidity. But because one particular wall is cold because of a lack of insulation the condensation (water going from vapour to liquid phase) will be concentrated on that particular wall.
The condensation will continue to occur as long as you continue to add moisture to the air via cooking and bathing (hot showers, baths).
That's the bit I am missing here, it just does not add up, condensation is not something that simply keeps accumulating water on a wall if it's cold enough, there's a saturation at some point. The question is, how fast is this saturation reached? If it's fast, then isolating one out of 3 walls may not create additional moisture on the non-insulated wall.
Sorry, I hope I don't come over as being stubborn, I'm genuinely interested in insulating (I have to do it at some point), I just like to understand things and so far I do not understand why isolating 3 walls out of 4 would generate additional moisture on the remaining wall.
' I do not understand why isolating 3 walls out of 4 would generate additional moisture on the remaining wall.'
you gey problems with mold way before you are anywhere near 'the physical limir of condensarion'. You dont want to be near it.
The question is not whether the amount of consensation will double or quadruple. It is weather you will have mould problems. If your wal starts getting wet, you will have mould peoblems.
It is cold as f in this place all winter. It's also hot as f in these new 37 degree summers.
So the question is, is the problem the old homes, or our insistence to live in inefficient buildings in places with poor climates?
Of course in this country, there's more demand for housing than can be met, so living someplace modern (efficient/comfortable) is not necessarily an option based on price. So the next choice is relocating to a different country which has a more livable climate.
I love architectural history, but we would all be better off if modern engineering and design decisions were made on new structures to replace the grossly inefficient current ones.
What I’m trying to say is that this is about incentives, not about how old things are. The modern building let their tenants cover the AC cost while the old one had water heating instead included.
Also, there's a new government initiative to provide incentives and special financing for property owners (who rent their property) to bring the efficiency of all properties up to a decent minimum level by 2030 if they wish to be allowed to continue renting them out. I imagine there may be some exclusions for certain very old properties, especially historical/monumental ones. But regardless, it should have a big positive impact.
The stories sound like comedy: entire block of flats was built the wrong way round, someone moved into theyr flat and found the balcony was missing - the balcony door just led to a 30 meter drop. They forgot to lay cable down for internet, so a new block only has 8 megabit ADSL. The building I am in, they made the holes for fire sprinkles in the wrong place - so there is a hole in the ceiling, but nothing behind it. The sprinkler is 20 cm away from it, inside the ceiling, and if something goes wrong it won't actually be able to pop out
better insulation is not cheap and therefore not everyone can afford to do it. Also the same people who want renewables are usually opposed to building new housing so there's that.
This makes insulating this house an absurdly bad financial decision, since once you have moisture damage in any part of this material, you can basically demolish most of the walls since it soaks like a sponge.
Mind you, I have not started going into the pitfalls of the legality of even touching a house this old in Germany, where you have to deal with "Denkmalschutz".
Insulating new construction and retrofitting insulation are two absolutely different things and barely have anything to do with each other from the cost-benefit ratio.
My house in Sweden is from the 1950's and I still had to be _very_ mindful when adding insulation. The best thing I've found is cellulose-based insulation, basically shredded newspapers lined with salts and pressed to sheets. The can buffer a lot of moisture without developing mold.
In old buildings with solid walls you can get condensation on the walls that will evaporate because the living space is heated and we'll ventilated. If you clad that wall in insulation you can prevent the evaporation which leads to damp problems.
Newer building codes have started to mandate more external insulation:
* https://www.buildingscience.com/documents/insights/bsi-001-t...
Depending on the climate zone, up to half the insulation may be mandated to be on the outside (behind some kind of cladding (brick, stucco, siding) to protect it from UV and bulk water).
Per the above article, by having the outside be insulation, your interior structure is kept warmer, and so condensation is less likely to occur.
Do a search for "Joseph Lstiburek" and "Matt Risinger", who have lots of articles and videos on building science.
As the article notes this price decline was predictable decades ago, but you can't really blame people for being dubious about predictions. Maybe the people who got it right were just lucky.
But since real actual installed wind and solar became cheaper a while ago, the people still openly arguing against renewables slide ever close to cartoon supervillain status.
The alternate explanation is that nuclear is a sick technology, and the Green movement is not responsible for its failure. Nuclear was so weak even a group as feckless as the Greens could have success against it.
Do you think lobby from fossil fuel companies just sat on their hands all this time?
If there's many billions of dollars in value to be created, that will trump anything a NGO can whine about. That's why we're still burning so much fossil fuel. Nuclear was vulnerable because it wasn't creating value.
I'm not convinced enough people know that renewables are cheaper to make the latter claim you're making. For example, in some places as soon as renewables come online they get priority access to demand, and other fuel sources get the leftovers. That's still a subsidy, just by another name. So I don't know if they are cheaper.
Finally, the point about renewables isn't only cost, it's also reliability. The subsidy I just mentioned falsely obviates the need for renewables to be reliable from a cost perspective, but that doesn't mean that needing a high base load (and higher the more we move to electric vehicles) isn't the most important thing to supply.
And none of that is about people "not wanting renewables".
yeah, but fossil fuels get subsidies of all sorts, not just polluting for free, but even things like leaving the british taxpayer to pickup the bill for cleaning up old infrastructure they no longer need
https://www.theguardian.com/business/2019/jan/25/british-tax...
Also, maybe if there is any risk of damage to surroundings like with hydro batteries there would be need to deposit amount of money that covers them fully.
But as with any problem, let's first start with the stuff causing the damage.
Let's get oil and gas and coal to pay for EVERY negative externality.
This is positive ridiculous. Are you serious in 2022? Your electricity is surely mostly sourced from hydrocarbons. Are you paying "true cost"? Surely not. If electricity was suddenly twice the cost due to carbon costs (which is probably the true environmental cost), you would be shouting from your windows to build more solar panels and wind turbines.
What? Why would you think that?
Plus, people usually oppose nuclear which is an expensive but stable renewable option.
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 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.
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 shouldn't put solar panels on my roof because it would not fix someone else's problems? What kind of logic is that?
I think it's a good point even if stated quite poorly.
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.
What comments in this discussion are saying is that solar panels won't be cost effective, for some or possible the majority of people.
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
So that's an actual solution to the problem!
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).
Only if the efficiency is 100%. In practice it's lower than that, so reducing consumption is better than increasing production.
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 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.
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.
Your sample size is too small to make generalisations.
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.
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"
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.
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.
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.
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.
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.
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?
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.
> Are you referring to https://www.bauprofessor.de/wirtschaftliche-nutzungsdauer-ge... ?
No I mean my number that approximately half of housing buildings are younger than 1977, so approximately 50 years.
This refers to a survey by the government, see box on bottom: https://www.bundesregierung.de/breg-de/themen/klimaschutz/kl...
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.
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.
[1] https://de.wikipedia.org/wiki/Liste_der_Volksz%C3%A4hlungen_... [2] https://option.news/wohnraum-im-wandel/
> 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.
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.
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.
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!
Not for their own good, but for the common good sure there is a legal basis. Eigentum verpflichtet.
Same direction as mandating solar panels for roofs.
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.
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.
Citation needed. This number is absurd.
So, around 200 million or so households. Each household (even if it's an apartment) needs both external and internal insulation improved.
Same goes for things like stores, factories, schools, government buildings, and all other non-residential buildings.
Most buildings are built before new energy standards (https://ec.europa.eu/energy/eu-buildings-factsheets_en). In some countries (esp. the Eadtern block) you probably need to teardown old buildings because you can't just simply insulate them (https://news.ycombinator.com/item?id=32202169)
I'd say "100 years" is a conservative estimation
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.
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.
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.