Amount of the monthly installment

Hello , why are you ignoring my posts? Why don’t you post the offer?

I believe the price includes 4 LAN sockets. Otherwise, there are enough power outlets and outdoor sockets. I don't have the satellite information in mind right now..

Really LAN and not just telephone sockets? Patch panel in the utility room included + connection included? Are 4 LAN sockets enough? You don't need overkill, but I find four sockets very few in a new build. It's best to use a double socket that is also wired with 2 cables.

This was just a small example that is often not considered at the beginning. The performance specification from T+C would be quite interesting. Some objections will hurt you at first, but you still have time to counteract them.

Sessi, I really hope it works out for you, but I would seriously put the offer here on hold. Surely some people here can still point out issues that you haven’t noticed, but which will probably cost you a lot of money or annoy you later on (and missing power outlets are just one point). You obviously have VERY (!!!) little knowledge, and personally, I find it a bit strange to sign a contract without knowing how the financing will work. But the horse has already bolted. What I stumbled over: we don’t need any frills, we have a gas boiler and no underfloor heating!!! Uh, you do realize that a gas boiler can also operate underfloor heating, right? You’re just using radiators, but one has nothing to do with the other. A heating system can be powered by solar, pellets, oil, gas, wood, etc. How I implement the heating is something else. These are the kinds of details that I’m sure don’t just make me gulp, and it simply gives the impression that you really don’t know much about the subject. And that’s a good basis for nasty surprises! There are a considerable number of people here with a lot of experience (some have built multiple times themselves) or are even professionals. Why don’t you use this wealth of knowledge that has kindly already been offered to you several times? Surely it won’t change the fact that you (in my impression, quite naively) have already signed a contract, but it can help you to defuse many pitfalls in advance. Use it!

A heating system can be operated with solar, pellets, oil, gas, wood, etc. How I then implement the heating is another matter.

According to the 2016 Energy Saving Ordinance, it is mandatory to operate additional solar thermal or pellet stove with a gas boiler; natural gas alone no longer complies with the Energy Saving Ordinance.

I would not do without underfloor heating in a new building, especially not in such a small house. We previously had radiators with gas heating and now underfloor heating also with gas, that is definitely a difference. The radiators, even with bleeding, still made noises from time to time, for example when you increased the temperature. You can never really clean them properly, there are cracks everywhere that you can't reach well and the radiators take up space that you need in a small house. Without underfloor heating, tiled floors are freezing cold in winter, with underfloor heating it is simply much more comfortable, especially in the bathroom. I also can't imagine that the extra cost for underfloor heating should be that high, have you asked about that?

Best regards
Sabine

Yes, according to the Energy Saving Ordinance of 2016, gas boilers must additionally operate solar thermal systems or pellet stoves, natural gas alone is no longer in compliance with the Energy Saving Ordinance

That is not correct; for example, gas + controlled residential ventilation with heat recovery + underfloor heating are also in compliance with the Energy Saving Ordinance.