Energy Saving Ordinance 2014 + Gas condensing boiler without solar + Controlled residential ventilation

Hello,

to comply with the [Energieeinsparverordnung], you have to build with renewable energy or the energy demand must fall below a certain value, right? In the second case, insulation may be omitted.

My goal is to keep the investment costs as low as possible. According to my information, geothermal energy is not possible in the planned construction area where we want to build. That leaves gas condensing boilers and air-to-water heat pumps. As far as I know, the investment costs for gas condensing boilers are lower than for air-to-water heat pumps.

So for a gas condensing boiler to comply with [Energieeinsparverordnung 2014], solar thermal or insulation is required. Which would be cheaper here? It is often said that solar thermal systems do not pay off – but insulation to meet [Energieeinsparverordnung] (minus 15 percent, right?) will surely pay off, won’t it?

So we are talking about a gas condensing boiler without a solar thermal system, but with [WDVS] to comply with [Energieeinsparverordnung 2014]. I am naturally concerned about moisture, mold, etc. with this insulation, so ideally it should all be combined with a controlled residential ventilation system.

In addition, there should be underfloor heating, but according to my research this does not cost more or hardly more than normal radiators.

Is all this a possible and also sensible approach? Gas condensing boiler without a solar thermal system, [WDVS] to comply with [Energieeinsparverordnung], and controlled residential ventilation with heat recovery to prevent mold and ensure a pleasant climate. Also underfloor heating.

The goal is the lowest possible investment costs. But operating costs should also pay off in such a heavily insulated building, right? According to my calculation, only a few hundred euros per year for natural gas remain.

Oh yes, the building material should not be aerated concrete because of sound insulation. So [Poroton] and [Kalksandstein] come into consideration, right? Which would be cheaper? What are the advantages and disadvantages here if you want to build a house according to [Energieeinsparverordnung] standard? That is, fulfilling [Energieeinsparverordnung] standard without renewable energy.

If the exterior wall is thick enough (36 cm or more), you might be able to do without [WDVS]. It depends on the material of the bricks. Needs to be calculated. I share your consideration regarding gas condensing boiler and air-to-air heat pump. We came to the same conclusion. Controlled residential ventilation with heat recovery is not mandatory under the [Energieeinsparverordnung 2009]. What about [Energieeinsparverordnung 2014]? No idea. If not, this technology is a matter of taste.

Controlled residential ventilation with heat recovery is probably not mandatory, I just thought about it because these new buildings are like sealed bunkers. We are currently living in an old building and find the climate very pleasant. Due to moisture, etc., measures must be taken in new buildings to restore the pleasant climate that one would already have without these new building standards anyway. :)