Calculate heating load to determine the size of the ground source heat pump

My general contractor can only provide me with a heating load calculation once the execution planning has been approved, he has tendered the trade accordingly to his 3-4 partner heating installation companies, and the calculation is then done by them. Can this be done by oneself? Are there online calculators for this? Can companies be commissioned for this at affordable prices? I need the heating load calculation to determine the geothermal heat pump (size kW) and, of course, the required drilling. Does anyone have advice?

I would leave that to a professional; if the calculation is wrong, you have to live with it for your whole life. You either won’t get the place warm or you pay huge amounts in heating costs.

Yes, you can do it yourself – but with mistakes. Most GÜs put 15 cm everywhere anyway and 10 cm in the bathroom. There are also no heaters exactly sized in kW.

In summary: yes, you can do it, but why should you – that’s what you pay your GÜ for? Tell your GÜ that you would like smaller laying distances and that he should not save on the insulation – or ask him what insulation thicknesses he usually plans and post that here.

You generally don’t pay huge sums for heating with new buildings anymore.

Calculate the u-value when you have your energy saving ordinance. For drilling, check with your state mining authority – because it also depends on the extraction capacity of your soil. Tell your drilling company to use well-conductive grouting material.

If the heating system is undersized, it definitely affects the costs. When I think of the heating element in a geothermal/air-to-water heat pump, for example.

I didn't say that you should choose a heating system by lottery...

If the heating system is designed too small, it certainly affects the costs. I only think of the heating element in a geothermal/air-to-water heat pump.

Just as it really costs when the heating system is way too large. But the devices are only available in approx. 2kW increments anyway. If you calculate that with a 5% error, the system usually fits. Otherwise, it is only a matter of "leisure"; if you have the structure/plan of the house and the insulation thicknesses, you can manage it quite well yourself.