Poroto T9 without WDVS and without solar thermal

Hello everyone,

I spoke with a company today and they were of the opinion that you do not get a building permit for masonry made of poroton (T9) as a single-shell construction and without solar (WW)??? Is that correct??? I was under the impression that in such a case you only have to insulate the building 15% better??? So what is correct now?

Just take a look at the [Energieeinsparverordnung]. It contains everything you need to do and what you need.

It depends on the heating system.
I guess you just want a gas heating system.. that's no longer possible, it now has to be renewable, so with solar.
Or you take a heat pump, then you don't need solar. Doesn't make much sense anyway... When it's cold outside and the solar doesn't provide any power, your heat pump has to work harder... But it also has a poor efficiency because it's cold.
Of course, you can also do a geothermal drilling, or some collector surfaces... All pretty expensive and whether it works depends on the professionalism of your heating specialist.

Oh yes, I chose the following for my new building:
Gas + two solar collectors for hot water preparation.
Decentralized residential ventilation
24 cm Poroton brick + 12 cm External Thermal Insulation Composite System (ETICS).
24 cm insulation between rafters
5 cm perimeter insulation of the floor slab
= KFW 55 ! ;-)

Solar, only for DHW in my opinion makes little sense. It is just used to meet the legal minimum requirements. It probably hardly brings any savings when you offset the high acquisition costs... If I can’t avoid it, then I will probably take solar for DHW + heating support.

Why should that make little sense? Whether you relieve the gas boiler by heating the water tank through the solar system, or relieve the gas boiler by heating the water tank partly through the solar system and partly the heating circuit... it's the same. If you do that, please plan accordingly twice as many solar panels as you would need for the domestic hot water support, otherwise it really doesn't make sense ;)

So with T9er it is certainly harder, but not completely impossible. It will then probably be towards >=42.5cm wall.

@Nutshell
Of course gas without solar also works, you just have to implement compensatory measures (15% better insulation). I myself also build gas without solar and even achieve KFW70.