Energy Saving Ordinance 2016 without active ventilation and exhaust

Hello everyone,
we have an offer from a developer for a terraced house. It states that it will be built according to the energy standard Energy Saving Ordinance 2016 (somewhat less efficient than Kfw 70, if I understood that correctly). According to the specifications, of course, a thermal building envelope will be created. A passive ventilation system is planned (through micro-slits in the windows). This passive ventilation is sufficient when you are not there yourself. Otherwise, you have to ventilate yourself.

My question:
Is passive ventilation and the omission of an active ventilation system still state of the art today? Are houses still often built that way nowadays?

Thank you very much in advance for your feedback.
Stefan

Yes. It is common and works. I would just plan for an exhaust fan, for example in the bathroom. So that the house has a desired airflow, coming in through the slits, out at the rotor. Our house is built like this, it works well. Ventilating properly once a day is still mandatory. We do that. Karsten

So after spending a lot of time on it, I can tell you the following:

A controlled residential ventilation system is not necessary in most buildings, unless the contractor needs it to meet his calculations for [KFW] etc. For a house according to the Energy Saving Ordinance, you can do without a system as long as you consistently carry out the necessary manual ventilation. Be it by opening the windows or the passive ventilation you mentioned in the windows.

A controlled residential ventilation system is a convenient thing and can make life easier, but it is generally not absolutely necessary.

We now have a decentralized controlled residential ventilation system and are treating ourselves to a central system in the new building, but only because we are not the most consistent ventilators on this planet.

And I would recommend everyone to invest in this; who ventilates adequately anyway, and it is a very comfortable thing. Looking to the future, there will certainly hardly be any new buildings without it.

Regards

Steffen

I can tell you from my own experience that water tends to accumulate in these slots in the window. I think it is condensation. Whether it is serious or not, I can't tell you, only that I have often seen water there. We are currently renting a new apartment, so the windows here are quite new. Even when I was with the general contractor, he advised me against the slots in the window, as he had also heard of problems. An alternative to central or decentralized ventilation could also be ventilation via the roller shutter box. We are not building according to KfW, but according to the Energy Saving Ordinance, ventilation solely by opening the windows is not sufficient.

We only have the rule Air window ventilation.. We have condensation in the bedroom which settles on the roller shutters and causes the slats to freeze... otherwise there are no problems. Humidity now in winter at 40% even without excessive ventilation.

The only disadvantage is the constant airflow in the area of the ventilation.

Surely it is not the latest standard and one reopens a tight envelope over intended points on the windows, quite funny windows with low U-value and then such slots come in

Long story short, I would not do it any differently in the next house.