Electricity consumption at home, what is your consumption?

or diffusion-open houses without controlled residential ventilation,

Hmm...someone has obviously been completely taken in by the seller. "Diffusion-open houses" is typical and baseless marketing nonsense. There are either airtight houses according to the applicable standards or else leaky ones, which is called construction with defects. But the myth of breathable walls has always been around and regularly circulates everywhere.

ETICS in new buildings is questionable anyway, that's why we plastered clay bricks in our case

Definitely. There aren’t many houses with ETICS here in the construction phase, but one of them is already showing dark spots on the exterior plaster after 13 months where the controlled residential ventilation exhaust comes out. It's basically the same phenomenon as in ETICS houses where the windows are constantly tilted. There, the plaster above the windows also turns black everywhere.

Even with WDVS, a lot, even very much, can be done wrong.

Controlled residential ventilation exhaust air comes out

That has nothing to do with controlled residential ventilation alone; several factors play a role. These are so-called thermal bridges that promote algae growth. This can happen to you on a house without ETICS as well. I can give you enough examples. Just pay attention to cross stripes at floor transitions.

Simply use high-quality plaster with algae inhibitor.

Hmm...someone clearly got completely fooled by the seller. "Diffusion-open houses" is typical and baseless marketing talk. There are either airtight houses according to the

Clay bricks have a vapor diffusion value, and therefore vapor diffusion-open houses have existed for several centuries, which has nothing to do with airtightness.

This has nothing to do with controlled residential ventilation alone; several factors play a role. These are so-called thermal bridges that promote algae growth. This can happen to you on a house without ETICS just as well. I can show you enough examples. Just pay attention to transverse stripes at the floor transitions.

Simply use high-quality plaster with algizit.

Ok. So the neighbor has two problems, construction areas that are thermal bridges/ exhaust air directly on the house wall and inferior plaster. Yeah, he’ll be happy when I tell him that.

But the transverse stripes only appear if the front side of the concrete slab between the floors is not insulated. If you don’t deal with this, you normally don’t know.