ᐅ Energy-Efficient Home Renovation: Our Experiences

Created on: 24 Nov 2024 12:05
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benno123
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benno123
24 Nov 2024 12:05
Hello, as mentioned, I would like to share our experiences with our home renovation, insulation, and other related work.
First of all: It can be worthwhile.
I say "can" because the topic is complex and cannot be generalized.
Let me start: Nine years ago, we bought a semi-detached house built in 1935, with double-walled hard-fired brick masonry (probably lasts a thousand years).
The windows are double-glazed plastic frames. During the initial renovation, we removed the cellar insulation (granulate) and installed 15 cm (6 inches) of polystyrene insulation and underfloor heating on the ground floor. Later, the roof needed attention; a lightweight metal roof was installed over the shingle roof. I made sure (this is important) that the roof overhang was extended towards the gable by about 30 cm (12 inches).
Two years ago, we insulated the exterior walls with only 8 cm (3 inches) of mineral wool boards due to structural constraints (I think it’s better than polystyrene because of vapor permeability). My advantage: I had done this elsewhere under supervision before, so I was able to do it myself. Therefore, the material costs for around 80 m² (860 ft²) were approximately 5,000 euros, including scaffolding rental for four weeks. At the same time, we replaced the old gas heating system with an 80-liter (21 gallon) hot water tank with a new condensing boiler, hydrogen-ready, including a 20-liter (5 gallon) integrated hot water tank (more details on that later).

Heating costs before: 20,000 kWh annually. Now, for the past two years, about 7,000 kWh per year. Considering that the last winters were milder, this is roughly a reduction by half at least. Unfortunately, since both renovation works happened in the same year, I cannot specify how much of the savings come from the insulation or the boiler replacement.

But in our case, it definitely paid off and will have paid for itself within a few years.
I can definitely recommend insulation overall—just like you wouldn’t go outside without a coat in winter.

Regarding the gas heating: We also considered a heat pump. That might be better in the long run. But first, I had no experience with it, and second, the costs were almost three times higher. Now, when I read that in other countries, like Denmark and the UK, they cost only about a third of what they do here in Germany, I find that suspicious, if true.
I don’t want to go into more detail here; everyone can form their own opinion. By the way, electric cars also cost only a fraction of the price in other countries compared to Germany.

I’ll stop here for now. If anyone has questions, feel free to ask.

Regards,
benno123
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Arauki11
24 Nov 2024 22:15
Just to get a response:
The fact that insulation leads to reduced heating costs has been known for a long time and is clearly intended, just like wearing warm clothing during winter.
Prices differ in other countries, as is common in many areas; for example, food prices here have been cheaper for years compared to other places.
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Frauke187
24 Nov 2024 22:18
I assume your property is located in eastern Germany. The purchase price in 2015 was probably still relatively affordable. The renovation also sounds very reasonable.

The result is what matters, and if you save more than half of your energy costs, then the energy retrofit has definitely been successful.

Things that were declared dead tend to last longer, and the same will likely apply to gas heating systems. I don’t believe they will ever be operated with hydrogen. Hydrogen is already doomed to fail, as are heat pumps.

This might make sense in new builds but not in older buildings like yours. Perhaps the hot water production could have been realized with a heat pump, but even there, the gas boiler is more efficient.
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nordanney
24 Nov 2024 22:20
benno123 schrieb:

I don’t want to say more about this here; everyone can form their own opinion. By the way, electric cars in other countries also cost just a fraction of what they do in Germany.
Actually, not in other countries. Mainly, it’s just the Chinese—but their car and battery industry is being unnaturally boosted with billions. And please don’t ask what the workers earn and how their conditions are.
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Frauke187
25 Nov 2024 07:37
To be more specific.

An employee in China earned an average of 120,698 yuan per year in 2023. This corresponds to about 16,810 US dollars annually, based on the year-end exchange rate of the Chinese renminbi to the US dollar.

The statement by @nordanney is incorrect.
nordanney schrieb:

There are mainly only the Chinese – but their automotive and battery industries are artificially boosted with billions, and please don’t ask now what the workers earn and how they are doing.

Many workers in China have achieved a modest level of prosperity. Prices are significantly lower than in Germany.

To put it in context, my annual salary is only 21,600 euros. However, I face considerably higher prices. Is the situation for the Chinese worker really that bad?
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nordanney
25 Nov 2024 08:17
Frauke187 schrieb:

@nordanney’s statement is incorrect.

What exactly is incorrect?
Frauke187 schrieb:

Are Chinese workers really treated that badly?

I never said that. However, a skilled worker in Germany assembling a car in Wolfsburg earns several times more than a worker in China.
This means that labor costs in China are significantly lower than in Germany. As a result, cars can be produced more cheaply in China.
Frauke187 schrieb:

@nordanney’s statement is incorrect

Therefore, the statement is accurate regarding the cost situation in China.

By the way, are you perhaps a new boxwood?