Control climate with underfloor heating or via the ventilation system?

No, not quite - especially since roof insulation doesn't really cost much. Above all, you shouldn't base something like that on 3-4 responses from a forum...

Bring as much mass as possible to the roof - usually only glass wool is used. You don't really gain anything in terms of summer thermal protection with that...



It depends on the device - some have a silent mode. I also don't know if the same noise limits apply as for the outdoor units of a heating system (but I think they do).

We had a very good device from Fujitsu, but above 30 degrees you could already hear something from outside.

For me, the outdoor unit is on the rear extension on the flat roof. There are no problems with the neighbor there.

purely out of interest:
In the new construction - would such an installation of the air conditioning have an impact on the KFW calculation and thus possibly on the funding? Such an air conditioner can potentially consume quite a bit of energy.
I am thinking of the example of the circulation pump discussed here in the forum, where it was mentioned that one could possibly lose the KfW status because of it.
If that is the case, it is advisable to consult an expert again for any subsequent planning to avoid endangering the applied-for KfW status and suddenly facing a financing gap.
For houses that are already built and approved, the "changed" KfW value hardly interests anyone anymore. After approval, no one will come by anymore and do a re-inspection after X years (I assume).
A future buyer would rather be happy to get a KfW house + air conditioning.

No, not really – especially since roof insulation doesn’t actually cost that much. Above all, you shouldn’t depend on 3-4 answers from a forum for something like that...

Put as much mass as possible onto the roof – usually only glass wool is used. You don’t really gain anything in terms of summer heat protection with that...



Depends on the device – some have a silent mode. I also don’t know if the same noise limits apply as for the outdoor units of a heating system (but I think they do).

We had a very good device from Fujitsu, but at over 30 degrees there was already some noise audible from outside.

My outdoor unit is on the rear extension on the flat roof. There are no problems with the neighbor there.

If I understood the architect correctly, he mentioned something about a wooden board. For this additional insulation measure, a net amount of 2,700 euros was estimated.

I am aware of how to evaluate the informational content from the forum. I understand this as a suggestion, which I ultimately have to coordinate with the respective craft business and architect.

The actual question is rather whether the additional roof insulation makes economic sense if the house can be cooled down with air conditioning?

Counter-rafter insulation is not only for cooling but also for soundproofing and, of course, cold protection. Besides, you have a rainproof sub-roof - so it’s not that simple. You won’t cool “the hut” down anyway, because once the devices are off, the temperatures rise quickly again. I wouldn’t do without it... rather without the air conditioning.

Now, after the first summer where I could hardly or not at all sleep due to the heat during those few weeks, a split unit was installed in the bedroom.

I don’t know what a split unit is, but I think I want one too

We have installed air conditioning or are currently installing it - one unit in the living room, three in the respective bedrooms and children's rooms.

And then you have a unit outside standing/hanging? How can I imagine that? I googled air conditioner once: there are units that are relatively small and are installed on a room wall. I could live with that in the bedroom.

but I refrained from it because ->personally<- I have no problems with "a few weeks of somewhat warmer [weather]".

It’s the same with us! At least I thought so, because I also like it a bit cozier. But through the large south-facing window quite a bit of sun comes in during summer and heats up strongly. Also, we don’t always have the roller shutter down. In the old terraced house, we genuinely had the entire front with windows in the bedroom - so we were used to the heat. But this heat also escaped again through the 78 insulation ... In our 2014 house, it stays trapped.

Apart from this thread, I haven’t given any thought to an external air conditioning unit, that’s why I’m asking.

Hopeful greetings

and then you have a device standing/hanging outside? How can I imagine that? I once googled climate control units: there are devices that are relatively small, they are installed on a room wall. I could live with that in the bedroom.

Exactly, one device stands/hangs outside (somewhere), one in the room - that is what you googled (unfortunately I’m not allowed to link anything here). It is usually only 70-80 cm wide and 20-30 cm high.

For just one room, you are definitely under 2,000 euros including installation for retrofitting.