KfW 100 or 70?

Hello, I am new here so please excuse my ignorance. I would have liked to use the search function but it always shows me errors. Now to my concerns. We recently bought a plot of land and are now looking for the right house for us. One only hears about Kfw ;) So far we have informed ourselves about the 70 series, but I have some problems with the ventilation system. Now my question is, do you also need a ventilation system for a 100 house, or is it recommended? I haven't been able to find anything about it on the internet so far. And the last person I asked either couldn't or didn't want to explain the difference in requirements to me. In addition, a wooden house would also be an option for us, which could then be clad with bricks. Which standard would this correspond to? Can you say that in general? I assume KfW100 would definitely be met. Thanks in advance

Hi, so: What does a ventilation system have to do with Kfw70? Nothing. What does a ventilation system have to do with comfort? You can also create a reasonable indoor climate in other ways – possibly with very frequent ventilation rounds through the house. Is that comfortable? The consequence of insufficient ventilation is often mold. What speaks against a ventilation system? From my point of view: the price. But the ventilation problem would really become a problem for me without a ventilation system. Regarding a clinker-clad wooden house – that can mean anything and nothing. So it cannot be classified generally, as wooden houses can be so very different.

Well, with an (additional) ventilation system you can certainly achieve Kfw 70.
A ventilation system also helps you, with the closed construction, to "breathe" -> against mold formation.
But does KFW 100 still exist?
Nowadays you have to build with renewable energies, soon an even higher standard!
By wooden house with cladding you probably mean timber frame construction... a Finnish wooden house is not clad ;)

No, you cannot make such a general statement (your question), it all has something to do with insulation!

Note: layman's opinion! And regards!

Even if one only builds according to the Energy Saving Ordinance, one should still not dispense with the installation of a ventilation system.

Hello,

I see it similarly to Mycraft. In new buildings, I would never do without a central ventilation and exhaust system.

The gain in comfort alone, never having to müssen ventilate again, is worth the extra cost for me. But the reliable removal of moist air and, above all, the partial recovery of heat from the exhaust air should not be overlooked.

Regards,

Dirk

Hello,

We recently bought a plot of land and are now looking for the right house for us. All you hear about is KfW ;). So far, we have inquired about the 70 series, but I have my issues with the ventilation system. Now my question is, do you also need a ventilation system for a 100 series house, or is it recommended?

If you want to take advantage of KfW funding, you can't avoid a KfW 70 efficiency house. Independently of subsidized loans, I wouldn't recommend it to anyone anyway. You should always look to the future and not lose sight of a possible later sale of the property; not to mention the potential savings on energy costs.

You don't necessarily "need" a ventilation system if you rely on renewable energies; with a conventional gas/burner boiler, it critically depends on the location of the plot in relation to the sun. Sometimes it "works out" without one in calculations, but mostly it doesn't. Whether foregoing a ventilation system is sensible or reflects the disadvantage you apparently see in installing one can surely be answered by the search function here; you have already received initial assessments.

So far, I have not been able to find anything about it on the internet. And the last person I asked couldn’t or wouldn’t explain to me the difference in the requirements.

Look at the KfW pages; there the requirements of the different efficiency classes are explained in layman’s terms.

Also, a wooden house would be an option for us, which could then be clad with brick slips.

Who comes up with the idea of cladding a wooden house with brick slips and why?

Rhenish regards