Is it reasonable to use material for the exterior wall without insulation?

0.09 means the lambda value, so yes, thermal conductivity. In the case of Poroton bricks, I think it is even included in the type designation. I believe there are also 0.07 ones.

You need reinforcement in the plaster for external insulation because the facade insulation panels are softer than bricks. Try knocking on such a styrofoam wall :)

Negligible in monolithic construction.

We have a monolithic wall structure with 36.5 cm stones and the exterior plaster was nevertheless applied with reinforcement. However, I have no idea what that cost in terms of price. Our architect always specifies it that way, and the plasterer obviously does it that way very often as well. It definitely seems to be very high quality.

The living climate in the house is great and I wouldn’t want any ETICS... That was the case with my apartment in a section of the extension. The roofer wasn’t careful with a ladder once and whoops: hole in it. Besides, it simply is and remains a thick Styrofoam shell...

Do you have any more opinions, should I ask my construction company again to include reinforcement? Where does that go, in the top layer (synthetic resin plaster) or in the base plaster?

The full-surface reinforcement layer is as a rule used in a 2-layer plaster system between the first and second layer. Whether the reinforcement layer is needed depends on various factors. For a 2mm topcoat, I would use a full-surface reinforcement layer. Otherwise, there are also manufacturer specifications on how to apply the plaster system.

Just ask the construction company again and have it explained.

Interior/exterior plaster unchanged: - 365mm Poroton ends up somewhere in the corner U~0.21 depending on which brick. - 300mm Poroton + 60 ETICS U~0.18 - 240mm Poroton + 120 ETICS U~0.16 The total wall thickness is always the same. If you look at the requirement catalogs, variant 1 corresponds to Energy Saving Ordinance 16, variant 2 exceeds KfW55, and variant 3 reaches the KfW40 region or "3-liter house." Don't just think about winter. Summers are also getting warmer and longer; for example, an ETICS also prevents the brick from heating up in the sun. With the next Energy Saving Ordinance, it will be difficult without ETICS; then the topic will finally be settled.

With the next Energy Saving Ordinance, it will be difficult without ETICS, then the issue will finally be settled.

There are still 42.5 and 50 wall constructions WITHOUT insulation... Should still be possible even with new Energy Saving Ordinances that may come.

On the topic: I would at least have reinforcement applied at the transitions from Poroton <-> concrete/insulation