Energy saving regulation with gas boiler and heat recovery ventilation instead of solar?

I mean the solar heat is only for water - and I read that you consume about 1000 liters of water per year per person

Your domestic water consumption is higher. About 120 liters per person per day. However, you are right in this regard that not all is used at that temperature,

The washing machine, the dishwasher cold water. The coffee machine too. Quickly wash paws, cold. Brush teeth cold. So, hot water is quite limited. What goes away with a shower? Let's say man three minutes, woman 4:30? No idea. Karsten

Hi, so personally I find ventilation with heat recovery more sensible. It is an investment that can pay off all year round. Solar can only be used on sunny days and is also high in investment.

Gas is used for heating?

Yes, gas is used for heating - my consideration was that I had currently planned a controlled ventilation system because of the shutters, if I save on the solar panels then it almost equals the cost of an upgrade to the ventilation system with heat recovery (PLUGGIT).

The only drawback is these grilles in the floor. On the ceiling it would be even more expensive.

You still have to factor in better insulation; without solar, the controlled residential ventilation alone is not enough. In other words, cost-wise, it's not exactly 1:1.

I recommend installing ventilation with heat recovery. We lived without ventilation for the first 8 weeks and therefore I can only keep emphasizing the incredible increase in comfort. By the way, we also have a controlled residential ventilation system from pluggit.

I think heat recovery is mandatory if you want to meet the share of renewable energy according to the Energy Saving Ordinance. I am not going with one-to-one yet. Because, to my knowledge, the solar system is clearly cheaper than this controlled residential ventilation with heat recovery. But since you should take forced ventilation with fan motor and RegelAir window rebate ventilators as basic, 2000 on top.