Solid house. Which stone?

Hello,

we want to build (have built) a solid house.
Now the question arises for us, with which type of brick.

The goal is to achieve a KfW efficiency between 55 and 70.
I have also read that the type of heating contributes to whether the value turns out higher or lower. Now, on the one hand, I don’t know how much, for example, an air-water heat pump contributes to improving this value.
What I want to avoid is that the KfW value is just above 70 when I heat with gas and only falls below 70 because of an air heat pump, just barely meeting the requirements.

Am I already correctly informed about this?

The question then is, which brick (is that enough by itself, or does extra insulation have to be added) is suitable.
I am repeatedly offered a 36.5 cm T10 or T9. Is that sufficient, even if I say I want to heat with gas?

About the framework:

We plan a single-family house / city villa approximately 10m x 10m
- triple glazing
- with an automatic ventilation system
- about 180 sqm of living space
- closed fireplace

I am already grateful for your tips and experiences.

...The goal should be to achieve efficiency between 55 and 70 with the KfW.

Why? Those are significant differences!

...I also read that the type of heating system contributes to whether the value turns out higher or lower.

Basically, two values must be met, Ht´ and Qp´´. The first describes the thermal quality of the building envelope, the second more the system technology.

...What I want to avoid is that the KfW value is just above 70 when I heat with gas and only falls below 70 because of an air heat pump, just to barely meet the values.

Very unlikely, because the air heat pump uses environmental energy, gas does not.

...The question then is, which brick (is that sufficient by itself, or does it have to be insulated additionally) is suitable.

KfW 55 is hardly achievable monolithically.
With higher Ht´ requirements, I would separate load-bearing and thermal insulation functions anyway.

...I’m repeatedly offered a 36.5 cm T10 or T9. Is that sufficient, even if I say I want to heat with gas?

For the Energy Saving Ordinance or KfW 70 probably, but you must compulsorily purchase a solar thermal system. Unfortunately, this is usually uneconomical in single-family houses. With gas, the 15% rule without solar thermal system is better.
A good alternative is often an air heat pump or ground source heat pump (depending on boundary conditions) + photovoltaics. In the annual balance, heating and domestic hot water can often be achieved at "zero cost" regarding consumption costs.

Best regards.

Hello €uro,

Thank you for the detailed answer. My question now is, what is a solar thermal system and why is it compulsory to buy it together with T10 or T9?

Thank you

Hello,

....My question now is, what is a solar thermal system and why is it mandatory to buy it with T10 or T9?

Solar thermal system => Solar thermal installation According to the EEWG, a certain share of energy must come from so-called renewable energies. In this case, by means of a solar thermal system. However, you can also make use of the so-called 15% rule, which means 15% improved insulation compared to the required energy saving ordinance standard value.

Best regards