Lowering the supply temperature in underfloor heating more complex than expected?

By the way, the NAT currently ranges between -8 and -18°C depending on the district. Anyone who designs their supply temperature at 30°C based on this value... there's no helping them anymore.

With today's knowledge I would do that too, but just a year ago I had zero knowledge of most topics. Only a second house build will probably take place in the next life, I won't put my family through that again. ;-)

How was it again... the first for the enemy, the second for the friend, and the third for yourself?

By the way, the NAT is currently between -8 and -18°C depending on the district.
Anyone who designs their supply temperature at 30°C based on this value... there is no helping them anymore.

Your generalization doesn't help anyone either. Especially since you don't provide us with your argumentation.
Obviously, some users are looking for a way to achieve a lower supply temperature below 35°. As has already been elaborated in the topic, it doesn't have to be 30°. But 32° would also be a good result. At least from my point of view.

In the whole discussion about general contractor (GU) or individual awarding, one must not forget that you never have a direct comparison. We are also really upset about some topics that we didn’t know before, and there were times when I thought, "Man – now I’m building a house for so much money and can’t even plan everything the way I want to. Why didn’t I just build with an architect?" But a) you simply don’t know what could have gone wrong with an architect or how much more expensive it would have been. Certainly, some things would have been planned/implemented differently, but it would probably have been even more stress/effort. At least we have a fixed price from early 2022, which still holds. No one can tell me how the price increases in the last year would have affected us if we had built with an architect. Therefore, I still believe that building with a GU was the right decision. Compromises simply belong with it – with some, the house provider can be negotiated with, with others maybe not. Regarding the flow temperature, I will now wait for the calculation and then have the plans given to me and see further. It would be great, for example, if I could convince our GU to install underfloor heating under the shower ;).

How satisfied / dissatisfied are you with your Vaillant? Aside from the operation – are you satisfied with the noise level, etc.?

a) However, in the recommended standard, the architect is also commissioned with site management and is then supposed to ensure that all trades comply. The general contractor's site manager works in the interest of the general contractor and is often less useful to the client in his role than a site manager. b) Most price increases occurred in 2021. In 2022, many prices have already gone down again. It can be assumed that a fixed price from 2022 already comfortably includes all actual price increases plus a safety margin due to recent experiences. This is also shown by the many threads here in the forum with reports from general contractors trying to push through change orders despite the fixed price or trying to evade the fixed price deadline with delay tactics. But you should not tar everyone with the same brush. There are also positive examples such as the general contractor of , for example. Likewise, there are also bad architects, of course. I claim, however, that this can be recognized earlier in the process or that you still have more control over the entire project later on than with a general contractor. After the revocation period has expired, you are practically at the mercy of the general contractor. With an architect, you still have the possibility to solve individual construction phases differently. I hope for you that your GC is one of the good ones. Today, I would always recommend clients in the pre-contractual phase to choose individual contracts for the construction instead. I also find it sensible to hire an additional construction consultant if you are an inexperienced layperson yourself.

As for the flow temperature, I will first wait for the calculation and then have the plans given to me and then see what to do next

Then take a look at the floor area in the bathroom to see if the shower is included, then it would be standard and no extra charge. We are happy not to stand on cold tiles when showering.