Photovoltaics & heat pump. Experience value for heating 4 apartments?

We will receive our heat pump in the next few weeks and want to use it in combination with a photovoltaic system for heating a total of 4 apartments. One apartment has 125 m2 of living space and the other four apartments, which will be rented out after renovation, each have 45 m2. In total, that amounts to about 300 m2.

Since we have no experience due to a complete renovation, I wanted to ask here in the forum if anyone can provide an estimate of how many kWh/year are needed only for heating the aforementioned 4 apartments via the heat pump? This is solely about the value for heating the apartments, not for the required electricity in everyday life. Thank you very much!

Since we have no experience due to a complete renovation, I wanted to ask here in the forum if anyone can give an estimate of how many kWh/year are needed just for heating the aforementioned 4 apartments via the heat pump?

But you must have hired someone during the renovation who calculated everything for you and also designed the heating (or heating capacity for the individual apartments). It thus depends on how you renovated. Only for aesthetics or at best at KfW40 level? With 300 sqm, there are worlds of difference between the respective heating costs.

You must have hired someone for the renovation who calculated everything for you and also designed the heating (or heating capacity for the individual apartments). It therefore depends on how you renovated. Only for aesthetics or at best to KfW40 level? With 300 sqm, the heating costs can vary greatly.

The house is being renovated with a KfW loan as a single-family house 70. Since it is already over 40 years old, it was the only option and we have to convert to a heat pump, photovoltaic system, and of course appropriate insulation.

Is there underfloor heating in the house?

What kind of heating is currently in the house and does it still work?