ᐅ Solid Masonry Construction: Brick Question

Hello,

I am planning to build a KfW55 solid masonry house and am currently unsure which bricks are truly suitable.

The company specified:

Exterior wall:

36.5 cm (14.4 inches) porous smooth-planed perforated brick with tongue-and-groove edges, laid with thin-bed mortar.

The requirements for an energy-saving regulation house are met without additional insulation.

UNIPOR W07 U-value 0.18

There are really very different opinions regarding bricks.

I would like to hear your thoughts on this.

I will also receive other offers and can gladly add the suggested bricks later.

I know people who have built with this and are very satisfied with it today. What they always say is that they would use 42cm (16.5 inches) bricks now.
The question I have is more about what alternatives are available? No building material has only advantages, and for me, it’s more about weighing what matters most (insulation value, soundproofing, monolithic construction, price, and so on).

And why would they use a 42cm (16.5 inches) brick?

Purely from an energy-saving perspective, he always says that with the 42cm (16.5 inches) wall the U-value is 25% better, and that the additional cost was probably worth it. Whether that is true is something everyone has to decide for themselves.

We are now facing the same question. So far, two contractors have planned to use insulated 36.5cm (14.4 inches) blocks for a KFW 55 standard build. The contractor we last spoke with recommends using non-insulated 42.5cm (16.7 inches) blocks instead. Their reasoning included better "ventilation" as well as insulation.

What are your thoughts on this:
Non-insulated 42.5cm (16.7 inches) vs. insulated 36.5cm (14.4 inches).

Does anyone happen to know the price differences as well? I have a second appointment next week where I will ask about this.

The narrow brick creates a slim base ;-). In other words, with the same external dimensions, you get more interior space. You can try calculating it yourself...