Solid house construction - choosing the "right" stone

Hello everyone,

first of all, I have to admit here that I am rather inexperienced in construction and I apologize in advance for my possibly somewhat naive question.

My wife and I have purchased a plot of land in BW and are now planning the construction of a solid detached house, fully basemented, with a double garage (standing next to the house).
During our initial discussions with the builders, we encountered very controversial statements regarding the question: Which type of brick do you recommend for building the house?

The house construction will definitely be done with a wall thickness of 36.5 cm WITHOUT full thermal insulation. It does not have to and should not necessarily become a KfW 55 or even KfW 40 house.
Unfortunately, the statements differed with various reasons between "we recommend the Hochlochporoton brick" and "we have always built with aerated concrete (=Ytong)" and have never had a moisture problem with it.

For Poroton as a building material, we were repeatedly told about the T10 brick. Reasons for why red were, among others:
- better indoor climate
- less moisture absorption by the brick (if it gets moisture during construction, it does not absorb that much)
- more natural, as it is burnt brick
- less residual moisture than aerated concrete
- better sound insulation

For the white brick, it was "advertised" with:
- cheaper than red
- better insulation
- easier to work with
- no red dust when drilling holes
- better grip, as there are no webs that can break out

Please excuse my somewhat blunt statements. However, these roughly reflect the statements of the builders. We would be very grateful for any input regarding the choice of brick. (If relevant: We do not necessarily want to install a ventilation system with heat recovery, but are considering window rebate ventilators and air extraction in the wet and basement rooms. However, we have not yet decided on this).

Thank you in advance for your experience reports.

How should one help without knowing your personal needs?

It basically doesn't matter unless you have special requirements for soundproofing.. And in that case, neither would be the stone of choice, but rather [Kalksandstein] plus insulation. You can find various threads about this here in the forum.

It has absolutely no impact on the indoor climate whether it's [Porenbeton] or [Poroton], with or without additional thermal insulation. Every house nowadays must be built airtight... And this is proven by the blower door test. Walls cannot breathe.

Regarding the central ventilation system, I would reconsider in your position. Economically definitely not sensible, but a huge increase in comfort and not really feasible afterwards (except for decentralized systems which, however, have significant disadvantages).

It has absolutely no impact on the indoor climate whether it is aerated concrete or Poroton, with or without additional thermal insulation. Nowadays, every house must be built airtight... And this is proven by the blower door test. Walls cannot breathe

That is of course wrong. Plaster and walls do regulate moisture differently. The summer thermal protection is also different.

I would recommend a 42.5 brick unfilled. It always has good reserves when it gets tight with the 36.5.

The discussion unfortunately tends to become religious. Under normal conditions, there is no knockout criterion against any of the systems. Not even against WDVS. If someone argues with hazardous waste, you should mentally switch off right away. Choose a general contractor and take what they prefer to install and go with your gut feeling.

The same applies to controlled residential ventilation. Question your usage behavior regarding ventilation and then decide, and don’t let anyone convince you that you can only build with it nowadays. It very well can be done without, but in my opinion, it is harder to decide than with stone.

I live in Ytong. Without ETICS. And that is okay. Dry, warm, and affordable. And drilling into the wall also works well. Warning: This is not a statement claiming that living in Poroton is worse. I would let sympathy for the company and price decide.