Air-to-water heat pump without buffer storage | Heating installer refers to building energy law requirement

Besides the rhetorical outburst that I really do not like, I would like to add something. Which of the builders here has received a room-by-room heating load calculation including the design of the underfloor heating from the standard general contractor/subcontractor/heating engineer/developer? I put forward the thesis that this is likely in the single-digit percentage range. The consulting engineer criticized here therefore provides a service for the money that offers real added value. Mostly monetary, but also in the "automation" of the underfloor heating.

Is that really the case? I would have assumed that those who do not have it are in the low single-digit percentage range.

: Sorry, I was mistaken. It was €40 in costs. In NRW.

Is that really so? I would have assumed those who don't have it are in the low single-digit % range.

A reasonable and meaningful result cannot be expected here. Too few will express themselves. Fortunately, I built a KfW Efficiency House 55 EE, plus 13.68 kWp photovoltaic. For the design of the underfloor heating and the heat pump, I was able to learn a lot here and in other forums. Room-by-room heating load calculation, according to the general contractor and the heating engineer, is standard there. The same applies to us. However, we increased the requirements and these were then also included in the calculation. As a result, we chose the smallest Arotherm plus 35/6 (instead of 55/6) and the forward flow pipe diameters of the underfloor heating are 11 cm everywhere and 5.5 cm in the bathroom. For 90 sqm area we have 13 heating circuits and a flow temperature of 31° with NAT. According to the heating engineer, the supplier of the underfloor heating always participates in the design with him.

We have received this complete heat load calculation from our general contractor.

...that's great. Unfortunately, not every general contractor delivers this service, let alone a heating installer. If it had been like that with us, I could have also done without the well-known engineering office.... but unfortunately, that was not the case. Therefore the "detour" >> "still reached the goal" << Our heating installer is definitely very enthusiastic about the result of the commissioned engineering office. He admitted he couldn't do something like that! The same goes for the statement from the energy consultant. Meanwhile, our developer even goes so far as to adapt his future buildings to the "heating" trade as in our "precedent case" .... that's a step in the right direction (my personal opinion)

is that really so? I would have assumed those who don't have it are in the low single-digit % range

As far as I have gathered, the opposite is more the case. ...and on the topic of costs: We have a written commitment that the total costs (approx. €950) for the ERR approval, as well as the unused hardware (heating & electrical trade), will be removed from the trades and credited. Our investment was practically the time we spent to finally hold the approval in our hands... and a essential aspect is the fact of being in a legally compliant environment. After all, the junior might want to sell the house someday... ;)

So the subcontractor of my GÜ, who then dropped out due to too many inquiries on my part, also had a room-by-room heat load calculation. Unfortunately, it was not complete (controlled residential ventilation not considered) and the subsequent sizing was done according to a standard procedure.