New construction Poroton T7 MW 36.5 without controlled residential ventilation

So not having to ventilate goes a bit beyond the supposed ventilation efforts... both in winter and in summer I like to keep the windows closed because there is a reason why I invested €300k in a house: the weather should stay outside. If I didn't care, I would have moved into a tent – there it is dry too.

You can turn and twist it however you want, plastic bags or yogurt cups built like houses nowadays require air exchange.

And that is only achievable if you work from home or someone is there during the day... if it is purely a "sleeping house," then nothing works anymore except for a [Kontrollierte-Wohnraumlüftung], at least not in the city.

Because here I cannot simply leave the windows tilted/opened in summer or winter. Otherwise, I risk coming home to find the house involuntarily "tidied up" by some gentlemen.

If you don't know a house with [Kontrollierte-Wohnraumlüftung], you don't miss it. However, my wife and I notice the difference clearly when we are at friends' or neighbors' houses "without" it.

Where mold is supposed to form in the pipes is also beyond me... it's not an incubator. It simply lacks a breeding ground here... I once posted pictures somewhere here showing what a system looks like after 3 years of continuous operation.

Exhaust air: light layer of dust
Supply air: like newly installed
Fans: light layer of dust
Heat exchanger: like new

The systems are usually only audible at full load.

Where space is supposedly lacking for it is also incomprehensible to me. All my piping hangs on the ceiling in the utility room. The system itself is on a wall just below the ceiling (so there would still be room for a washing machine underneath), the piping through the house is on the raw floor beneath the underfloor heating insulation... so I have no space losses at all. Everything was built where unused space was available anyway.

And the 50 euros for electricity and 10 euros for filters per year really don't make me poor... but for that, there is always clean air in the house.

No matter how you look at it, plastic bags or yogurt cups, houses as they are built nowadays require air exchange.

However, I find this term somewhat misleading. An ETICS (external thermal insulation composite system) is not airtight. Airtight is the interior plaster. A Poroton T7 house is just as airtight as a KS house with 30cm ETICS. This term plastic bag suggests that it is about the ETICS. But that is not the case.

If you only had a vapor barrier on the top and the house was open on all sides, then it wouldn't be airtight. The point is that the entire house is airtight. And this airtightness to the sides is achieved through the interior plaster, so there is no difference whether KS+ETICS or brick.

I only said that the term plastic bag evokes false associations. Some might think that we build without ETICS, meaning no plastic bag. The plastic bag effect is achieved by the non-plastic components of the exterior wall.