KFW70 with gas-solar heating

We have just received the heating load calculation for our house - 8.1kW.

And that despite our not excessive insulation...

Compared to before the Energy Saving Ordinance requirements, your insulation is already quite excessive. No one denies that insulating also has some kind of break-even point - but just look at the houses from 1995... 130 kWh/m² were more or less normal back then - what do you have? 60? So twice as good, and even in 1995 everyone complained that they had to insulate so heavily.

Our insulation over the top? It is just slightly below the [Energieeinsparverordnung] at the masonry

Roof is somewhat better...

Primary energy 38 and final energy 16...

The Energy Saving Ordinance 2009... the Thermal Insulation Ordinance of 1995 (predecessor of the Energy Saving Ordinance) specifies a maximum U-value for walls of 0.5 W/m²K, in the Energy Saving Ordinance 2009 it is 0.24 W/m²K - and as I said, I am sure that people were also complaining in 1995

So honestly... what exactly is politics supposed to do to reduce energy consumption? It’s either insulation or promoting environmentally friendly energy production...

Energy can also be saved during the construction of buildings. If in the not too distant future we only build passive houses (that's where it will lead), there won’t be much more energy to save. With today’s assumed twice as good insulation, 60, 70 or 80 kWh/m2 can be saved compared to the 90s. In 20 years, with twice as good insulation compared to today, one might still achieve maybe 10 or 15 kWh/m2 energy savings. The era of "more insulation" will probably be over...

So the big area left is the "grey energy," which still has considerable potential for savings. In the future, buildings should be constructed with materials that require little energy to produce and are easily recyclable. There are already initial considerations in this direction. For federal buildings, there is an effort toward sustainable construction based on a holistic principle. Maybe politics will then also come up with the idea to introduce this in KFW and similar programs?

In my opinion, that would be a step in the right direction: Who wants great "environmentally friendly" passive houses that consume a lot of energy before construction and then have to be disposed of as hazardous waste?

Back to the topic: For us, KFW subsidies have had their effect. We now have a solar system and reduce our energy demand because of that, even though it doesn't make financial sense...

Absolutely agree with you!

P.S.: We are also installing a brine water heat pump out of principle and for the love of the environment, even if almost everyone is trying to deter us from it almost violently.