markoopoloo wrote: >> what stage of construction are you at?
we have finished laying the foundations, but as the weather conditions improve, we are moving forward sharply.
This is the perfect moment to think about whether you are making a PC forever, whether you expect to install other heating and make chimneys. So the cost of the chimney + the area occupied by it. It is also important to determine what pump you will install. Most preferably ground energy. Then you need to determine what bottom source:
1. Coil made of pipes arranged horizontally in the ground - generally cheaper, but requires a larger area and does not allow for any development of the plot
2. Boreholes where pipes are inserted.
In the first case, it is good to prepare a well-sealed and insulated passage through the foundation wall, in the second case, either the same or you can drill within the foundations and insert the pipes directly into the PC area. This reduces costs and facilitates subsequent operation. Only problem with soil compaction around the hole, but that is manageable.
markoopoloo wrote: >> do you have a chance for gas

there is a chance, but I don't know when, besides, the gas from what I read (and what Mr. Eidur wrote) is less profitable.
Less, but when we calculate the investment costs, in my opinion, in most cases, PC loses to a condensing natural gas boiler. If, on the other hand, there is no chance for natural gas, it is indeed the most profitable.
markoopoloo wrote: >> what is your heat demand,
I will have an audit just done, I already have some estimates, but I doubt that it will be credible.
But in the case of a PC, it is necessary to establish the demand quite accurately. Too high means unjustified higher costs (you have to add to the difference in the price of the pump itself the higher cost of the bottom source). Too low means working with an electric heater / other heat source and much higher operating costs.
markoopoloo wrote: >> where you can install the pump.
I'll have a basement.
So you need to think about the method of connecting the lower source - as above.
markoopoloo wrote: >> The pump type depends on the above-mentioned ground conditions.
The soil is mainly clay, I have fertilized myself with some soil from 0.3 m, but it is not easy to dig deeper.
You do not need much deeper, but ask how much the boreholes in your area cost, for 80-120m and an excavator, because you will not dig the horizontal one by hand :)
markoopoloo wrote: >> And a parameter that hardly anyone pays attention to before buying is the noise level
the noise level generated by the pump ???
Yes, some make noise like old Minsk. The basement makes it possible to soundproof.
markoopoloo wrote: >> Basic errors are poorly made / designed lower source with no possibility of additional heating with a device other than PC.
The PC is supposed to be the only source of heating.
So special attention to detail is recommended. Consider also mechanical ventilation with recuperation. The heat loss for ventilation is quite large, and with airtight houses, good ventilation is important for comfort and protecting the walls from moisture.