This is neither about throwing money out the window nor "getting mold because Styrofoam is stuck outside." The opposite is true. Mold occurs because moisture condenses, because there are building components that are colder and thus the moisture present in the room air condenses. You haven't even understood the basic principles. Air passes through your walls... with which you are somewhat correct, because that is exactly the problem with your hot tip of interior insulation without a vapor barrier. Let me introduce you to the terms U-value, condensation, temperature profile, and dew point.
This is clearly about the topic of ventilation systems + 36 cm hollow bricks? I have already understood the basic principles that salespeople want to push me a ventilation system. I would assert that a ventilation system is not necessary in a brick house. Last summer, just for reference, with 38 degrees Celsius outdoor temperature, not even the Honeywell fan was necessary indoors because bricks compensate the heat outside and do not absorb it, unlike any prefab house with ultra-insulation. The same applies in winter: if you notoriously burn off the indoor humidity through vapor barriers and no ventilation. Then you have two options: aa) humidify the air using a machine (technology is waste after 20-25 years; money burnt) bb) or you occasionally open the windows? cc) or you buy yourself an air humidifier for 200 euros net + a few bottles of distilled water for a few cents?
Your post is (once again) nonsense – and more importantly – it is not conclusive. You write about new windows for 30,000 euros – hmm. Even I had "only" 27,000 euros for that, but I got the maximum insulation value with a Ug of 0.5 and a good piece over 50 sqm of window area if I remember correctly. You would have to have a really big place, as in the construction year 78 the living area/window area ratio was somewhat different than today. Your 2.5 tons of hardwood charcoal briquettes have a heating value of about 12,500 kWh, the 70 euros monthly for gas correspond to about 14,000 kWh. That makes a total of about 26,500 kWh – for a house that is probably only emergency heated in the coldest third of the year. The total annual heat demand is probably around 40,000 kWh. For a house from '78, I would then come to about 250 kWh/a/m² on 160 heated m².
Your post is just rough theory as well. Reason: 30,000 euros come together quickly if you take aluminum/wood combination windows. I don't care about the insulation value either because we turn the thermostats to frost protection during the day and the Bullerjan/Chief heats up miserably fast. Lighting basket with 2 handfuls of pellets + burning paste + 5 x hardwood briquettes. After 30 minutes about 20 degrees Celsius, even at -10 degrees Celsius outdoor temperature. Window offers for under 16,000 euros are on my desk; however, then plastic, including triple glazing + proper fittings due to weight. The place is already big; the cellar alone has over 400 m2 and fits about 12 vehicles + 20 motorcycles. There's so much steel in the cellar, you could probably build 4 x single-family houses?
I have all offers on my desk, from Köb solid fuel boilers, to Fröhling wood chip, pellet stoves, etc., combined with a thermal solar system (which brings almost nothing). My conclusion: a floor-standing condensing boiler + Chief/Bullerjan/wood stoves are the most effective systems, excluding AEG eco shower boiler (no instantaneous heating). I've calculated everything.
Conclusion: The more technology, the more money is burnt over the next 30 years.
Core problem in Germany: building is too expensive. And so I have thought about it. The heating saving effect from theoretical 240 kWh/a/m² on 160 m² is only theoretical. If you include the complete remodeling costs in the entire calculation, only a very small added value emerges, comparable to the calculations of thermal solar systems, which effectively bring nothing except that the builder's wallet gets decimated.
So 30,000 euros for windows (with what values actually) on 160 m² of living space... That's a statement. Do you have no exterior walls but everything made of glass? Also a statement are 1,400 euros heating costs for the 8 warmest months of the year. You are missing about 60% of the heating costs if you do not heat the house in winter (according to degree day distribution). Well – it's emergency heated... so let's say your costs correspond to about 50%.
There are enough exterior walls; The 1,400 euros heating costs do not interest me because every year I still get a refund from the gas companies. In addition, I can deduct about 50 euros per month for pump electricity/burner electricity from the total bill in winter, which I formerly paid. The advantage of the AEG eco boilers; the gas boilers can be completely switched off; that means from April to October the gas boilers hardly run; except if there is snow and 0 degrees Celsius in September. Emergency heating runs so the pipes don't burst from the walls. The water pipes/stainless steel have triple coating/insulation. They even withstand about -15 degrees Celsius for 2 weeks. It never gets colder anyway.
That would actually be 2,800 euros heating cost. If you could reduce this to well below 1,000 euros through proper insulation measures and new windows for about 50,000 euros, you would have amortized it in about 25 years and simultaneously done something for the environment. (Whereas the exterior plaster would probably be due anyway and should actually only be partially included in the energy refurbishment calculation)
Insulation and new windows would cost me about 70,000 euros; the square meter 22 cm Styrofoam insulation was calculated in a quote at 100 euros per m² (apparently these are the local prices?). But: When I recently saw an expert report about construction damage, damp house walls, mold, I turned away from the Styrofoam stuff. I don’t want that. KfW + subsidies don’t interest me either because I pay cash against invoice and don't have to take out loans. Analogously I can build however I want. The roof only gets a 400 mm interior insulation and that’s it.
If I were to have a new heating system installed, ultra-thick facade insulation + new windows, I would be at about 105,000 euros with a new roof + 15% surcharge for small stuff. Currently, the roof is tight, heating consumption is average (not perfect) but little technology that can break down and burn my money. For that money I’d rather renovate a 3rd, 4th house and sell it with profit.
If you prefer to be on the other side of the earth during the heating period due to your individual lifestyle, that has nothing to do with universally valid recommendations in the field of energetic building refurbishment but rather falls into the area of bar stool slogans.
But with your construction tips, maybe you can open a janitorial service in Phuket...
What do you mean by individual? I don’t care about the environment, whether I burn gas + briquettes for 1000 euros or 2000 euros per year. Besides, I also drive an 8-valve without a turbo. Why? Because these engines at least work reliably and don’t need a full overhaul every few thousand kilometers like DPF, turbo, etc. 2 liters displacement, 9 liters super, 10 liters LPG – that’s it.
Whoever wants to build an energy-saving house for 450,000 euros should go ahead. For me, it is pure marketing, backed by building societies that do the pre-financing then hope that one or another financially fails; then forced auction, then Zwegad, etc.
Building in Germany is way too expensive anyway. No idea why citizens voluntarily take on such high development costs? I would start there. It cannot be that an electrical cable, which you still bury yourself from the house via garden to the street distributor/ground sleeve, is still charged over 14,000 euros. Or sewer, water pipes, etc. The same applies generally to all the house building madness! There are countries where houses are built noticeably cheaper. More technology, more money burning, more waste in the future.
P.S. No wonder many completely leave in a few years?
Phuket does not interest me in Thailand. There are more beautiful places. And janitors? I am in the fortunate position to have work done.