Hello everyone,
Even though the topic of the "right" building services technology and its various advantages has already been discussed extensively, I still cannot answer the general question of whether a KfW 40 plus house is truly advantageous for me.
In many parts of the forum, it is mentioned that, purely for economic reasons, the standard according to the Energy Saving Ordinance (EnEV) is recommended and that the additional costs for a KfW house generally do not pay off. I find this hard to understand.
We are currently planning the construction of a new single-family house built with solid construction, without a basement, with approximately 200 m² (2,150 sq ft) of living space and underfloor heating. Without going too much into detail (although general and undetailed comparisons are always difficult), I would like to present the following simplified calculation:
Additional costs for KfW 40 plus compared to the Energy Saving Ordinance standard:
Ground source heat pump (deep drilling): €12,000 (€20,000 instead of a gas boiler with solar system for €8,000)
Ventilation system with heat recovery: €12,000
Photovoltaic system with storage: €15,000
Total additional costs: €39,000
Subsidies:
Repayment waiver through KfW 40 plus: €15,000
BAFA subsidy for geothermal energy: €4,500
Remaining additional costs: €19,500
Is it really the case that these additional costs of €19,500 do not pay off over a reasonable period? (There are further costs for KfW 40 plus, for example for construction supervision; however, these are largely also subsidized, e.g. through the KfW 431 program).
Furthermore, a low-interest loan (currently 0.9%) of up to €100,000 can be obtained from KfW, and other banks do not treat KfW loans as regular loans, which additionally improves one’s creditworthiness.
Would you still say that, based on these figures, a KfW 40 plus house is not economically viable?
Thank you very much for your insights!
Even though the topic of the "right" building services technology and its various advantages has already been discussed extensively, I still cannot answer the general question of whether a KfW 40 plus house is truly advantageous for me.
In many parts of the forum, it is mentioned that, purely for economic reasons, the standard according to the Energy Saving Ordinance (EnEV) is recommended and that the additional costs for a KfW house generally do not pay off. I find this hard to understand.
We are currently planning the construction of a new single-family house built with solid construction, without a basement, with approximately 200 m² (2,150 sq ft) of living space and underfloor heating. Without going too much into detail (although general and undetailed comparisons are always difficult), I would like to present the following simplified calculation:
Additional costs for KfW 40 plus compared to the Energy Saving Ordinance standard:
Ground source heat pump (deep drilling): €12,000 (€20,000 instead of a gas boiler with solar system for €8,000)
Ventilation system with heat recovery: €12,000
Photovoltaic system with storage: €15,000
Total additional costs: €39,000
Subsidies:
Repayment waiver through KfW 40 plus: €15,000
BAFA subsidy for geothermal energy: €4,500
Remaining additional costs: €19,500
Is it really the case that these additional costs of €19,500 do not pay off over a reasonable period? (There are further costs for KfW 40 plus, for example for construction supervision; however, these are largely also subsidized, e.g. through the KfW 431 program).
Furthermore, a low-interest loan (currently 0.9%) of up to €100,000 can be obtained from KfW, and other banks do not treat KfW loans as regular loans, which additionally improves one’s creditworthiness.
Would you still say that, based on these figures, a KfW 40 plus house is not economically viable?
Thank you very much for your insights!
stormtronix schrieb:
So for me, it has paid off, or am I missing something? You can only determine if it paid off by comparing the energy consumption of the KfW55 house without the additional €15,000 (approximately $15,000) cost and then projecting the savings over 20 years. Unless you received the €15,000 (approximately $15,000) from KfW as a grant with no extra costs or impact on your loan, then it certainly paid off.
S
stormtronix4 Apr 2019 14:29Hello Lumpi,
yes, the 15k came from KFW, so...
@haydee - we moved in August, but the photovoltaic yield/self-sufficiency has only been logged since the last week of October. The overall self-sufficiency is therefore just 20% when projected over a year – partly because I will likely use a significant amount myself for cooling during summer – I estimate 40-50%.
yes, the 15k came from KFW, so...
@haydee - we moved in August, but the photovoltaic yield/self-sufficiency has only been logged since the last week of October. The overall self-sufficiency is therefore just 20% when projected over a year – partly because I will likely use a significant amount myself for cooling during summer – I estimate 40-50%.
stormtronix schrieb:
@haydee - We moved in August, but the photovoltaic output/self-sufficiency has only been logged since the last week of October. The overall self-sufficiency is therefore just 20% when annualized. Among other reasons, I expect to use quite a bit myself for cooling during the summer – I estimate around 40-50%.Thanks, I’m curious to see how it goes. Please keep us updated. We also want to install a system in a few years, with storage if batteries become more affordable. Our mayor is currently testing one at his house.
I wouldn’t wait any longer; feed-in tariffs are decreasing, and who knows how much longer they will even be available...
You can still add a battery later, but I suspect they will become more expensive rather than cheaper, as the demand for electric vehicles will increase significantly in the coming years.
You can still add a battery later, but I suspect they will become more expensive rather than cheaper, as the demand for electric vehicles will increase significantly in the coming years.
R
robin19885 Apr 2019 12:18Thank you very much for the active feedback.
I would like to briefly share the concept we will most likely implement:
Gas condensing boiler with solar thermal system and controlled residential ventilation with heat recovery. In addition, adjustments to the building components to meet the reference values for KfW 55.
Advantages of the concept (in my opinion):
- Low heating costs due to the gas condensing boiler and good insulation
- Option to replace the heating system later with a fuel cell heating system (depending on future developments)
- Comfort and mold prevention through controlled residential ventilation (especially important with higher insulation levels)
- €5,000 (approx. $5,500) subsidy through loan repayment relief and access to low-interest loans (0.9% interest rate fixed for 10 years)
I would like to briefly share the concept we will most likely implement:
Gas condensing boiler with solar thermal system and controlled residential ventilation with heat recovery. In addition, adjustments to the building components to meet the reference values for KfW 55.
Advantages of the concept (in my opinion):
- Low heating costs due to the gas condensing boiler and good insulation
- Option to replace the heating system later with a fuel cell heating system (depending on future developments)
- Comfort and mold prevention through controlled residential ventilation (especially important with higher insulation levels)
- €5,000 (approx. $5,500) subsidy through loan repayment relief and access to low-interest loans (0.9% interest rate fixed for 10 years)
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