Hello everyone,
due to an interesting topic that has come up around our house construction plans and is causing us some serious questions, I’d like to put this question out there:
Which standard should we build to (Energy Saving Regulation, KfW 55, KfW 40, or KfW 40 plus)?
We are not ideologues, meaning our decisions are mainly based on two criteria:
1) Cost-effort (i.e. which option pays off over the long term)
2) Future viability
-> We are in our early/mid-30s and therefore expect the house to last a long time
-> We expect energy prices to rise
What has happened?
-> We were determined that if we build, it will only be a KfW 40 plus house. Assumption: Insulation has reached its peak development, with little potential left. The top level of insulation has been achieved. The development potential still lies with heat pumps and storage systems.
Therefore, we wanted an air-source heat pump, with as large a solar system as possible (9.99 kWp), plus an appropriate battery storage. Controlled ventilation would be a must in all variants. Goal: to produce all the electricity we need ourselves and end the year with a net zero balance. In other words, no electricity costs or any other energy expenses.
The following challenge then arose:
In our region, there are virtually no general contractors or shell contractors who offer this kind of solution at all. The only company we could build with relatively easily is the well-known one from Bad Fallingbostel. We’ve already had several discussions there, but I’m not entirely convinced. Sure, there are many advantages, but also some things that bother me.
Now we have gone on another tour through local providers.
The consensus: about 70% build to Energy Saving Regulation or KfW 55 standard. One company showed such incompetence in the first meeting and then zero customer service afterward that we can no longer imagine that they can deliver a house with a functioning heating system. One company is now insolvent. Another offers a maximum of KfW 55 (without any option to upgrade). Another would basically build anything for us but thinks anything above KfW 55 is nonsense.
In short: Our idea faces absolutely no support (except in Bad Fallingbostel). And now we are starting to wonder which path might actually be the right one (based on the points mentioned above).
I hope I’m not starting a debate that ultimately ends up as a “matter of belief.” The problem is that every scenario can apparently be made to "look good" with the right calculations.
I look forward to your experiences, opinions, and perhaps calculations on this topic.
Best regards
CarinaJ
due to an interesting topic that has come up around our house construction plans and is causing us some serious questions, I’d like to put this question out there:
Which standard should we build to (Energy Saving Regulation, KfW 55, KfW 40, or KfW 40 plus)?
We are not ideologues, meaning our decisions are mainly based on two criteria:
1) Cost-effort (i.e. which option pays off over the long term)
2) Future viability
-> We are in our early/mid-30s and therefore expect the house to last a long time
-> We expect energy prices to rise
What has happened?
-> We were determined that if we build, it will only be a KfW 40 plus house. Assumption: Insulation has reached its peak development, with little potential left. The top level of insulation has been achieved. The development potential still lies with heat pumps and storage systems.
Therefore, we wanted an air-source heat pump, with as large a solar system as possible (9.99 kWp), plus an appropriate battery storage. Controlled ventilation would be a must in all variants. Goal: to produce all the electricity we need ourselves and end the year with a net zero balance. In other words, no electricity costs or any other energy expenses.
The following challenge then arose:
In our region, there are virtually no general contractors or shell contractors who offer this kind of solution at all. The only company we could build with relatively easily is the well-known one from Bad Fallingbostel. We’ve already had several discussions there, but I’m not entirely convinced. Sure, there are many advantages, but also some things that bother me.
Now we have gone on another tour through local providers.
The consensus: about 70% build to Energy Saving Regulation or KfW 55 standard. One company showed such incompetence in the first meeting and then zero customer service afterward that we can no longer imagine that they can deliver a house with a functioning heating system. One company is now insolvent. Another offers a maximum of KfW 55 (without any option to upgrade). Another would basically build anything for us but thinks anything above KfW 55 is nonsense.
In short: Our idea faces absolutely no support (except in Bad Fallingbostel). And now we are starting to wonder which path might actually be the right one (based on the points mentioned above).
I hope I’m not starting a debate that ultimately ends up as a “matter of belief.” The problem is that every scenario can apparently be made to "look good" with the right calculations.
I look forward to your experiences, opinions, and perhaps calculations on this topic.
Best regards
CarinaJ
We built a KfW 70 house in 2013: with 14 cm (5.5 inches) insulation, solar was necessary for our gas heating system. The roof was insulated beyond the standard level. Our mechanical ventilation with heat recovery was not required, but we chose to have it anyway. This brought us close to KfW 55, but on paper that doesn’t really matter.
We are satisfied with this middle ground—consumption and technology that allow us to live comfortably under one roof.
Maybe you can build in a way that some features can be added later? That way you stay future-proof...
Best regards
We are satisfied with this middle ground—consumption and technology that allow us to live comfortably under one roof.
Maybe you can build in a way that some features can be added later? That way you stay future-proof...
Best regards
CarinaJ schrieb:
Hello everyone,
I have a few basic questions to ask. We would like to have a mechanical ventilation with heat recovery system (for comfort reasons, I am allergic, have had bad experiences with well-insulated houses, and due to work commitments, etc.). Naturally, we had focused on a central mechanical ventilation with heat recovery system. Does that still make sense? If you were to build according to energy-saving regulations, my understanding is that it would result in a properly insulated house with a gas heating system.
Our wish is to have underfloor heating throughout the entire house along with the mechanical ventilation with heat recovery system. How is this typically implemented?
You often see houses with solar panels as well. Does that make sense or is it completely pointless? It probably doesn’t pay off because the electricity consumption of the mechanical ventilation system is not high enough for the solar panels to be cost-effective. Correct? Or is there some combination (maybe including water heating) where it would be worthwhile?
Thank you very much for the enlightening contributions. Although this means a lot of rethinking and new researching for us now.
Best regards,
Carina A gas heating system combined with mechanical ventilation with heat recovery and underfloor heating is certainly feasible without any problems. That’s what we have, too. Or what did you mean by that?
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