ᐅ Is a ventilation system now mandatory for new buildings under the 2016 Energy Saving Ordinance?

Cunarder schrieb:

The goal is to build a KFW 55 house (solid construction) [...]
2. Is it feasible to do without it, or should the money still be invested?

Since everyone here has once again settled for proxy arguments: No, KFW 55 cannot be achieved without a controlled residential ventilation system with heat recovery. If your provider stubbornly claims otherwise, they should release you from any responsibility for the moment, as reality will catch up with them.

Iktinos schrieb:
Since everyone here keeps falling back on proxy arguments: No, KfW 55 cannot be achieved without a controlled residential ventilation system with heat recovery. If your provider insists otherwise, they should release you for now until reality catches up with them.

How do you justify that it is not feasible? I actually believe it is NOT mandatory, at least not if you do NOT choose the method based on reference values. However, I cannot guarantee this, as I am not an energy consultant.

Alex85 schrieb:
I got the impression that some of the "old hands" just don’t want to deal with the modern stuff. They’ll keep installing gas and solar until retirement because that’s what they know, and that’s fine for them.

I think so too. The airtight houses also seem to bother the old hands.

By the way, I bought about 2 square meters of G4 filters on Amazon and quickly replaced them myself on Saturday. Printing the 8-page instructions actually took longer than the replacement itself... the electricity consumption is very minimal – my energy and time investment without a mechanical ventilation system is worth more.

Regards, Yvonne

stefanc84 schrieb:
How do you justify that it is not feasible? I actually believe it is NOT mandatory. At least not if you don’t choose the procedure with reference values. But no guarantee for this, I am not an energy consultant.

I don’t need to justify this; a look at the KfW requirements profile is completely sufficient.

Iktinos schrieb:
I don’t need to justify that; a look at the KfW requirements profile is more than enough.

Maybe it would help some people to know exactly what you see at a glance there.
Because I don’t see the reason. Maybe the OP doesn’t either.

Iktinos schrieb:
I don’t need to justify this; just a look at the KfW requirements is enough.

Maybe it would help some people to explain exactly what you see with just a quick glance. I actually believe that statement is incorrect.

The 20 home builders were not only all against controlled residential ventilation systems, but most were also not familiar with the KfW requirements and conditions. It always went like this.
Construction professionals: “KfW 55 is not worth it. You don’t even need to think about it! It costs too much! You definitely need a ventilation system then.” We said: “No, we don’t need one, but we want it anyway.” Construction professionals: “Oh, you want it? Are you crazy!? It will just get moldy on you. All the germs and dust. You will also need solar thermal.” We said: “Our district heating is 100% supplied from renewable energy sources and is therefore rated positively by KfW. We don’t need solar thermal either.” Construction professionals: “Ah… well, let’s see what the energy consultant says.”
The first two times this unsettled us quite a bit because we thought they might be right—they are, after all, construction experts, unlike us. Then we got a second opinion and dismissed those two companies as not suitable. Eventually, we realized that the following appointments played out similarly.
It annoys me that all these people just repeat things they heard somewhere. Especially at a time when information is so easy to access. That’s why it also annoys me a little when you write “That’s how it is, I don’t need a reason.”

@TE: You can reach the KfW information hotline at 0800 539 9002 or ask an energy consultant. Both should confirm that a controlled residential ventilation system is not mandatory for KfW 55 and 40. It CAN be necessary if the rest of the insulation and heating technology are not sufficient. The overall package counts.