ᐅ Solid Masonry House. Which Type of Brick or Block?

Hello,

we are planning to build a solid masonry house.

Now we are wondering which type of block to use.

Our goal is to achieve a KfW efficiency rating between 55 and 70. I have also read that the type of heating system influences whether the rating is higher or lower. I would like to know, for example, how much impact an air-to-water heat pump has on improving this value. What I want to avoid is having the KfW rating just above 70 when heating with gas, and only reaching below 70 because of the heat pump, barely meeting the requirements.

Am I understanding this correctly?

The question is then which block (is it sufficient on its own, or does it require additional insulation) would be suitable. I keep being offered a 36.5 cm (14.4 inches) T10 or T9 block. Is that enough, even if I intend to heat with gas?

Regarding the framework:

We are planning a single-family house / urban villa approximately 10 m x 10 m (33 ft x 33 ft)
- triple glazing
- with an automatic ventilation system for supply and exhaust air
- about 180 sqm (1,938 sq ft) of living space
- closed fireplace

I appreciate your tips and experiences in advance.

emer schrieb:
...The goal should be to achieve a KfW efficiency between 55 and 70.

Why? Those are significant differences!

emer schrieb:
...I also read that the type of heating system influences whether the value is higher or lower.

Essentially, two values must be met, Ht´ and Qp´´. The first describes the thermal quality of the building envelope, the second relates more to the building services technology.

emer schrieb:
...What I want to avoid is having the KfW value just above 70 when heating with gas, and only dropping below 70 due to an air-source heat pump, barely meeting the requirements.

Very unlikely, since the air-source heat pump uses environmental energy, unlike gas.

emer schrieb:
...The question then is which type of masonry (is it sufficient on its own, or does it require additional insulation) would be suitable.

Reaching KfW 55 with solid masonry alone is hardly achievable.
For higher Ht´ requirements, I would recommend functionally separating structural load-bearing and thermal insulation.

emer schrieb:
...I am often offered 36.5 cm T10 or T9 blocks. Is that sufficient even if I plan to heat with gas?

Probably adequate for the Energy Saving Ordinance or KfW 70, but you will likely need to include a solar thermal system. Unfortunately, solar thermal is usually uneconomical for single-family homes. With gas heating, it is better to follow the 15% rule without a solar thermal system.
A good alternative is often an air-source or ground-source heat pump (depending on site conditions) combined with photovoltaic panels. In the annual balance, this can often provide heating and domestic hot water at nearly "zero cost" in terms of consumption.

Best regards.

Hello €uro,

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

Thanks

Hello,

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

Solar thermal system refers to a solar thermal installation. According to the Renewable Energy Heat Act (EEWG), a certain portion of the energy must come from so-called renewable sources. In this case, through a solar thermal system. However, it is also possible to apply the so-called 15% rule, which means 15% improved insulation compared to the required standard value of the energy savings regulation.

Best regards.