Newly built semi-detached house with 30cm T8 and air-to-air heat pump

Dear experts and readers,

we are considering the purchase of a new build (semi-detached house) with completion at the beginning of next year. Since we are laypeople in this field, I wanted to ask here whether 30cm T8 bricks (WLG08) in combination with an air-to-air heat pump make sense.

From initial research, this does not seem optimal to me in terms of insulation and the expected electricity costs.

Thicker bricks would probably be possible, but the living area is already quite limited (approx. 7.5x8m shell). I also tend to prefer a gas boiler (proven technology?). The basement has 24cm WU concrete and 10cm thermal insulation.

The partition wall to the neighbor consists only of 2x15cm calcium silicate blocks (including house partition wall panels). Is this sufficient for "normal" sound insulation?

I am grateful for any feedback. Tolino123

The 2x15 ks are very good, of course it can be better but that should be enough. I don't think much of air-to-air, okay it gets warm in the house but tiles are still very unpleasantly cold. Prefer underfloor heating with gas or air-to-water heat pump or gas with underfloor heating and solar. But it will definitely be more expensive.

Air/air – so without a hot water heating system directly through supply air is not possible with such exterior walls. With air as a heat carrier, the maximum heating load is limited to 10 W/m to create a comfortable environment. Otherwise, either the air exchange rate is too high or the supplied air is too hot at the inlet. And with 30 cm T8 you won’t achieve that; you have to build significantly thicker walls, monolithic probably 49 cm T8 or preferably T7. With the size of the building envelope, that naturally means a lot of space is lost. Timber framing with insulation between rafters and exterior insulation might be possible with 30 cm wall thickness.

Not everyone finds cool tiles uncomfortable.

Are you sure that a heat pump without a water-based heating system is being offered?

That must be a typo. A [Luft-Luft Pumpe] doesn't make any sense there. They are not efficient enough for insulation, you won't get any approval for that. Besides, where is the hot water supposed to come from?

After initial research, it doesn't seem optimal to me in terms of insulation and the expected electricity costs.

Thicker bricks would probably be possible, but the living area is already quite limited (about 7.5x8m body).
I also tend more towards a gas boiler (proven technology?).

Your initial research matches reality 100%. ;-)

However, you need to quickly erase from your memory that climate compressors are not proven technology. The technology is over a hundred years old and is manufactured and installed millions of times annually.