New building with electric heating

Thank you for your explanations! I know myself that it is somewhat different from a normal concept. : I did not speak of any underfloor heating but said: Quote:

Additionally, corn vector radiators (electric) should provide the base heat if needed. End.

And in every room (flat radiators on the wall). If I’m not in the mood to heat with the fireplace, it is still as warm as I set it via my smartphone. So much for "Back to the roots." I know what you mean but I think it is forgotten that I want to combine a fully modern electric heating system with smartphone control etc. with a wood stove. I enjoy adding wood and coal. Also because I know it is an environmentally good solution. With my system I would burn about 1000 kWh of electricity but also produce it myself. My actual question whether this is even possible with KfW 40 or 70 can probably be answered by no one here. : I think your KfW 40 standard comes from the air heat pump. You wouldn’t have gotten it with electricity only? Maybe that would be an option. But your technology also costs accordingly. Photovoltaics 10,000-13,000 euros, air heat pump and complete installation certainly 15,000 and then your KfW 40 standard with insulation etc. 10,000 euros? In that case I can also stick with KfW 70 with gas boiler and fireplace (modern). : I know that heat does not pass through closed doors. I already said normal door openings are unsuitable for heat distribution. Anyway, I will ask my questions to an energy consultant, because my concern was to find out whether with electric heating I am really rated so poorly that I would have to build a KfW 40 house in order to meet the permitted primary energy demand of a KfW 100 (minimum standard) at all. With a system efficiency factor of 2.6, my project is basically worthless anyway. I will probably then decide for a KfW 70 with gas boiler and hydronic fireplace. Standard

Hello,

: I never spoke of underfloor heating but: Quote:
Additionally, Kornvektor radiators (electric) are supposed to provide base heat when needed. End.

I understood that correctly, but I agree with you, I should have also put "no conventional underfloor heating was needed for that" in quotation marks, then it probably would not have caused confusion in two ways.

If I sometimes don’t feel like heating with the fireplace, it’s still as warm as I set it via my smartphone. So much for "Back to the roots"

And this is exactly the statement I translate as "back to the roots". You don’t want to use the fireplace only as a temporary transitional heating in the winter-spring or autumn-winter transition, but also as a full-fledged heating system for the entire single-family house in the cold season when you "sometimes don’t feel like it." That is as far removed from modern technical gadgetry via smartphone as my current location is from Timbuktu.

Also because I know that it is a good environmental solution.

That is certainly debatable

My actual question whether that is even possible with KfW 40 or 70 probably no one here can answer.

No, how should they? There are so many factors – beyond the location of the new building – to consider that a randomly correct answer would be like winning the lottery.

To answer this question reliably, you need the floor plan, the plot anyway, a soil surveyor, a structural engineer, and an HVAC planner. And then it still needs to be clarified whether you want to use funding or if you just want to know that you have mathematically achieved this or that energy efficiency house standard.

Rhenish regards

Well, there are values that I must meet at least in order to achieve a KfW 70 or 40 standard. First, there is the annual primary energy demand, which is calculated from heating demand (kWh) + hot water (kWh) multiplied by the system efficiency factor. You then divide the result by the square meters and must probably reach about 74 kWh per square meter (KfW 100) in order to be allowed to build at all. (There was the question whether this is even realistically achievable with electric heating.) Furthermore, the insulation values of the house or heat losses with a minimum standard of 0.4 W/m² x K count (for which 85 percent apply for KfW 70 and 55 percent for KfW 40). These values have nothing to do with the location or the plot but with the construction method. I go to the construction company and say I want to meet these values at least because I want the KfW 40 subsidy and the favorable loan. But if I build a house that meets the KfW 40 insulation values, it is probably calculated with an electric heating system with a system efficiency factor of 2.6 and the wood stove is not considered at all. And then a primary energy demand results that just meets the KfW 100 standard (if self-generated electricity can be deducted). With KfW 70 insulation values and electric heating, I probably would not be allowed to build at all. That’s how I understood it, and if that is correct, it makes no sense to use electric heating, since I already pay about 10,000 euros more for a house with KfW 40 insulation values and then lose the 5,000 euros for the KfW 40 standard because of the electric heating and also do not get a KfW 70 loan. I think that’s how it is, but I wanted to either get confirmation or correction. I understand that using a wood stove so extensively is not everyone’s thing. For me, it’s about the theoretical and legal feasibility, which also has to make financial sense for me. So I don’t know if that came across clearly... The electric heating could theoretically heat the whole house (radiators in every room) and I can control it via smartphone. And every kilowatt I generate with the stove naturally saves electricity costs... Thanks for your/their answer

The location is relevant because the annual heating degree days naturally affect the heating demand. Information about the property is interesting on one hand because the orientation of the house influences the solar gains through the windows, and on the other hand, information about the soil affects the effectiveness of, for example, a geothermal heat pump.

Also, I am afraid that the entire financial effort you have to undertake so that your electric heating primarily complies with the energy saving ordinance will be significantly more expensive than if you install a water-based heating system.

The other thing is, if you really insulate so extremely (KFW40 or better), where do you want to direct the waste heat from the stove? Stoves start at 5KW heating capacity. 5KW is far too much for such a house even at -15°C.

For this project, you really need a planner.

Hello,

These values have nothing to do with the location or the property but with the construction method. I go to the construction company and say I want to meet these values at least because I want the KfW 40 subsidy and the favorable loan.

Of course it has something to do with the location. A striking example for better understanding: a house on the Zugspitze requires different insulation than a house in the cozy Rhineland. And what if the soil survey, for example, shows that concrete supports must be installed in the masonry here and there, in the worst case the floor slab must be reinforced entirely or partially? Then your calculation is off because these thermal bridges (more steel/reinforcement) are not taken into account in your simple calculation. That is why every reputable provider will give you the same answer - first soil survey, structural analysis, calculation of heat demand and then see which heating system can be operated sensibly and, above all, economically. Basically, the following should additionally be stated under every offer - in essence: "The fulfillment as an efficiency house xyz cannot be guaranteed because the orientation of the building with regard to the cardinal direction as well as the fundamental location of the property is an essential factor in the calculation of the required energy saving verification."

Rhineland greetings