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!
Grantlhaua schrieb:
What kind of system do you have, with a layered buffer tank or another configuration?5.4 kWp photovoltaic system on the roof, and an 8 kW LG battery storage in the basement.
Additionally, an air-to-water heat pump. The house is over 40 years old.
On April 5, 2019:
Production: 18.46 kWh
Exported to the grid: 8.55 kWh (46%)
Consumption: 14.16 kWh
Purchased electricity: 4.24 kWh (30%)
We only have one meter for both heating and household electricity. And quite a few appliances. Side-by-side refrigerator, dishwasher programmed for noon, freezer chest, mechanical ventilation with heat recovery, circulation pump...
In general, every case is individual. For us, the difference between a 55 m² (600 ft²) house without a basement and separate apartment and a 40 m² (430 ft²) house WITH basement and separate apartment was almost exactly €100,000. The basement is a waterproof concrete shell, fully insulated, integrated into the ventilation system, has a comfortable ceiling height, partially floor-to-ceiling windows, spatially separated areas, its own bathroom, and underfloor heating. So, it's an expensive basement.
Most likely, just the additional building services and insulation would have cost €20,000–40,000 plus €18,000 for the photovoltaic system.
On the plus side, we have two subsidies of €15,000 each from the KfW loan program and the tax deductibility of the separate apartment spread over 50 years—or until the tax office stops considering the rental as genuine :P
You can look at it from so many angles that you’ll always get different results. It already depends heavily on the quotes, which can differ by as much as 100%.
We didn’t go for the entire KfW package. The conditions were worse than a regular loan, which would have partly nullified the repayment grant anyway. On top of that, you would have had to pay for an approved construction supervisor and deal with additional administrative work – maybe around 2,000 to 3,000 euros more overall, but that doesn’t make a big difference at those sums.
Regardless, we have (and would again) install all the related systems ourselves: controlled residential ventilation, photovoltaic panels, and a heat pump. Whether the KfW program is worthwhile really depends on the calculations.
We didn’t go for the entire KfW package. The conditions were worse than a regular loan, which would have partly nullified the repayment grant anyway. On top of that, you would have had to pay for an approved construction supervisor and deal with additional administrative work – maybe around 2,000 to 3,000 euros more overall, but that doesn’t make a big difference at those sums.
Regardless, we have (and would again) install all the related systems ourselves: controlled residential ventilation, photovoltaic panels, and a heat pump. Whether the KfW program is worthwhile really depends on the calculations.
Our shell building to Passive House standard cost about 20,000 euros (2017) more compared to KFW 55. Mostly due to insulation. The house was from the same supplier, with exactly the same features.
The difference in the shell construction is almost balanced out by removing the underfloor heating. We have a trial system from Stiebel Eltron/Tecalor.
With your additional cost of 19,500 euros, you won’t make it.
The battery storage likely won’t decrease either. Especially since your extra costs already include items that aren’t necessary for the Energy Saving Ordinance.
Take a look at Autark with Passive House. For more than a year now, all values have been broken down in detail:
Consumption, purchase, feed-in.
You probably won’t find a second house with the same values, because location, lifestyle, and so on change everything. These numbers haven’t been beautified by sellers.
An Energy Saving Ordinance house is not bad. Not long ago, that was even a standard eligible for KFW funding.
Financially, it’s not viable at the moment (according to the Passive House perspective).
What happens if the next step of the Energy Saving Ordinance comes or the construction boom slows down? That’s just guessing.
I think the comparison with Tesla is quite fitting.
The difference in the shell construction is almost balanced out by removing the underfloor heating. We have a trial system from Stiebel Eltron/Tecalor.
With your additional cost of 19,500 euros, you won’t make it.
The battery storage likely won’t decrease either. Especially since your extra costs already include items that aren’t necessary for the Energy Saving Ordinance.
Take a look at Autark with Passive House. For more than a year now, all values have been broken down in detail:
Consumption, purchase, feed-in.
You probably won’t find a second house with the same values, because location, lifestyle, and so on change everything. These numbers haven’t been beautified by sellers.
An Energy Saving Ordinance house is not bad. Not long ago, that was even a standard eligible for KFW funding.
Financially, it’s not viable at the moment (according to the Passive House perspective).
What happens if the next step of the Energy Saving Ordinance comes or the construction boom slows down? That’s just guessing.
I think the comparison with Tesla is quite fitting.
M
Mottenhausen4 Apr 2019 12:23It’s not worth it. Nowadays, if you want to build with insulation and a controlled ventilation system anyway, you can take advantage of KfW funding without significant additional investment. For those who want to build monolithically without any extras, it’s not worthwhile.
In case of a sale, it might be an advantage if the house, for example, meets future energy-saving regulations, but I wouldn’t count on it, as it’s uncertain whether anyone would pay even 1€ more for that.
For us, good insulation to the KfW55 standard combined with a gas heating system makes sense due to the very open design (open bathroom on the gallery…) and the increased heating needs of the occupants. Otherwise, in the long run, we would probably be spending a fortune on heating. But who actually has an open bathroom… I don’t really know anyone. So, we’re not exactly typical.
Always keep climate change in mind. Summers are getting hotter and hotter, and insulation also works very well in that regard.
Currently, interest rates range from 0.75% to 0.9% depending on the term. Then show me a comparable offer from the open market... (Plus the funding “gift” depending on the KfW standard of 5,000-15,000€)
In case of a sale, it might be an advantage if the house, for example, meets future energy-saving regulations, but I wouldn’t count on it, as it’s uncertain whether anyone would pay even 1€ more for that.
For us, good insulation to the KfW55 standard combined with a gas heating system makes sense due to the very open design (open bathroom on the gallery…) and the increased heating needs of the occupants. Otherwise, in the long run, we would probably be spending a fortune on heating. But who actually has an open bathroom… I don’t really know anyone. So, we’re not exactly typical.
Always keep climate change in mind. Summers are getting hotter and hotter, and insulation also works very well in that regard.
bierkuh83 schrieb:
The idea that the KfW loan offers better conditions is also a myth.
Currently, interest rates range from 0.75% to 0.9% depending on the term. Then show me a comparable offer from the open market... (Plus the funding “gift” depending on the KfW standard of 5,000-15,000€)
S
stormtronix4 Apr 2019 13:45I built a house last year, although it’s a small one with 136m² (1460 ft²). The additional cost to upgrade from KFW55 to 40Plus was “only” 15,000 with my builder. In return, it included thicker insulation, a minimal photovoltaic system plus battery storage, each with 3.6 kWh capacity.
I haven’t needed to heat for three weeks now, thanks to heat recovery ventilation.
Since February, hot water has been heated to 70°C (158°F) at midday by the 300-liter (80-gallon) heat pump/electric heating element combination system using photovoltaic power, which can maintain that temperature for over a day without sun.
The self-sufficiency rate has been above 80% for the last two weeks, and I’m even feeding electricity back into the grid.
There are four of us, with two small children, so at least one washing machine cycle plus a (heat pump) dryer and one dishwasher cycle run daily for free.
For me, this has been worth it—am I overlooking anything?
I haven’t needed to heat for three weeks now, thanks to heat recovery ventilation.
Since February, hot water has been heated to 70°C (158°F) at midday by the 300-liter (80-gallon) heat pump/electric heating element combination system using photovoltaic power, which can maintain that temperature for over a day without sun.
The self-sufficiency rate has been above 80% for the last two weeks, and I’m even feeding electricity back into the grid.
There are four of us, with two small children, so at least one washing machine cycle plus a (heat pump) dryer and one dishwasher cycle run daily for free.
For me, this has been worth it—am I overlooking anything?
B
boxandroof4 Apr 2019 13:49It can be a mistake to set the standard and place the order first. KfW houses (especially 55) can also be planned right down to the finish: an air-to-water heat pump for primary energy and a more precise calculation of thermal bridges that only takes place on paper.
I would first plan the house and building services in a way that makes economic and ecological sense. Insulation should be applied where it is cost-effective or where you will never have to access it again. A well-planned heating system and an energy-efficient floor plan, in my opinion, offer more benefit than the next higher insulation standard! Only at the end would I check how far off you are from KfW 55 or 40.
We built only according to the Energy Saving Ordinance, but consume less energy than most KfW 40 houses. In hindsight, I would admittedly have built to KfW 40, without the plus, because we are not that far off with the insulation and technology we ultimately used. During planning, we only considered KfW 55, and at the time, the subsidy was too low for the effort it required from us.
I would first plan the house and building services in a way that makes economic and ecological sense. Insulation should be applied where it is cost-effective or where you will never have to access it again. A well-planned heating system and an energy-efficient floor plan, in my opinion, offer more benefit than the next higher insulation standard! Only at the end would I check how far off you are from KfW 55 or 40.
We built only according to the Energy Saving Ordinance, but consume less energy than most KfW 40 houses. In hindsight, I would admittedly have built to KfW 40, without the plus, because we are not that far off with the insulation and technology we ultimately used. During planning, we only considered KfW 55, and at the time, the subsidy was too low for the effort it required from us.
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