Economic efficiency construction costs vs heating costs

How much buffer do you have in total? 10,000 euros is not much when it comes to outdoor facilities. We had roughly estimated about 20,000 left and are now happy to be able to get some more things done outside. Economically, you won't be able to recoup your 10,000 euros with any energy investment, at least not with a building constructed according to current Enervie standards!

How much buffer do you have in total? 10,000 euros is not much when it comes to the outdoor facilities. We had roughly about 20,000 left and are now happy to be able to have a few more things done outside after all. Economically, you won’t be able to recoup your 10,000 with any energy investment, at least not with construction according to current Enervie standards!

Approximately an additional €20,000. For now, the outdoor area will just be lawn (about 150m²). The garden is already prepared (topsoil leveled).

I’m not talking about investing the full €10,000. It’s mainly about the masonry. That should cost a few thousand euros.

How do you come to the statement "Economically, you won’t be able to recoup your 10,000 with any energy investment, at least not with construction according to current energy standards!"?

We have about 240m² of exterior walls. From T9 to T7 would be an improvement of 0.05 W/m²K. Assuming an average room temperature of 22° and an average outdoor temperature of 9° during the heating period (outdoor temperature below 16°).
Then I would have 270m² * 13K * 0.05W/m²K = 175.5W
With about 2000 operating hours of the heat pump, that would be 351kWh/year savings in heating energy.
With an average annual performance factor of 2.5, that’s 140kWh electricity consumption/year. At €0.27/kWh, that’s just under €40 savings per year.

Where is the calculation error?

With an average annual performance factor of 2.5, that is 140kWh electricity consumption per year. At €0.27 / kWh, that is nearly €40 savings per year.

Where is the calculation error?

... no calculation error. After 100 years you have regained your additional costs of the masonry (assuming you actually save that much);)

... no calculation error. After 100 years you have recovered your additional costs from the masonry (assuming you actually save that much);)

If you also calculate the interest on the capital, it takes even longer. :D

If you also calculate the interest on the capital, it takes even longer.:D

If there is more than 1% interest, it takes infinitely long

Exactly...everything pretty silly :) Therefore, we build 36.5 wall + gas..done. No floor heating, heat pump nonsense, and other eco gimmicks. And I hope our neighbors also spare us from annoying outdoor units. Those things are like the plague..I already know 4 cases where builders are directly in conflict because of the nighttime noise!!!