New construction - gas heating and controlled residential ventilation - without solar?

Hello,

we are currently planning our new building (start 2018).

I have a question:

Is it enough if we have a gas condensing boiler + controlled residential ventilation? Or is a solar system mandatory with a gas condensing boiler?

Best regards
fuba777

Short and concise, yes, that is possible. Solar is not mandatory across the board. However, a renewable share for heat generation is required, and this is also possible with [Kontrollierte-Wohnraumlüftung]. Another alternative would be biogas, but who actually has that. Your heating engineer will tell you otherwise, maybe also the energy consultant (or the person who prepares the heat protection certificate). But don’t let them tell you nonsense, they should then duly provide textual evidence that contradicts this.

For gas without solar plus controlled residential ventilation, you will need a correspondingly well-insulated exterior wall to comply with the energy saving ordinance. Only a professional can calculate that. What speaks against solar? It is probably cheaper than elaborate insulation.

... a well-insulated exterior wall, or no windows on the north side, or many windows on the south side. Or.... Everything is an interplay of several components and a calculation exercise for the expert

I basically think it is good without solar. It rarely has more benefits. However: since you are building new, will have a [Kontrollierte-Wohnraumlüftung], and correspondingly good insulation, your heating load will be so low that even the smallest gas boiler will still be too large. I would really consider a heat pump then.

That's how it looks, only the controlled residential ventilation is not enough... the whole package has to be right.