ᐅ Passive House as a Logical Choice? Are There Any Counterarguments?
Created on: 20 Feb 2015 19:54
V
Vogtländer
Hello everyone,
we are a family planning to build a house. So we have tried to gather as much information as possible. In the process, we have come across the passive house concept.
Do you know that feeling when you think you understand something and then wonder why everyone isn’t doing it that way? That’s exactly how we feel about the passive house right now. Are we missing something, or are there any arguments against building a passive house? I really can’t think of any.
Of course, it is somewhat more expensive, but if I recover the costs soon and then save money for life, I don’t understand, for example, why I would build a KfW 70 house instead...
So please either correct me or agree with me, but my conviction about the passive house feels a bit unsettling.
Thanks for your thoughts.
we are a family planning to build a house. So we have tried to gather as much information as possible. In the process, we have come across the passive house concept.
Do you know that feeling when you think you understand something and then wonder why everyone isn’t doing it that way? That’s exactly how we feel about the passive house right now. Are we missing something, or are there any arguments against building a passive house? I really can’t think of any.
Of course, it is somewhat more expensive, but if I recover the costs soon and then save money for life, I don’t understand, for example, why I would build a KfW 70 house instead...
So please either correct me or agree with me, but my conviction about the passive house feels a bit unsettling.
Thanks for your thoughts.
B
Bauexperte20 Feb 2015 21:53Good evening,
first, it is important to clarify what exactly is meant by a Passive House (PH). What has been required so far—when a municipality makes PH a condition for purchasing land—resembles a low-energy house rather than a true PH. A true PH, for example, does not have a conventional heating system but instead uses an air-to-air heat pump; expensive, high-performance windows are also one of its characteristics.
The additional costs mentioned here so far, from PH to KfW 70, are therefore not accurate. An increase of around 40% is more realistic.
Regards, Bauexperte
first, it is important to clarify what exactly is meant by a Passive House (PH). What has been required so far—when a municipality makes PH a condition for purchasing land—resembles a low-energy house rather than a true PH. A true PH, for example, does not have a conventional heating system but instead uses an air-to-air heat pump; expensive, high-performance windows are also one of its characteristics.
The additional costs mentioned here so far, from PH to KfW 70, are therefore not accurate. An increase of around 40% is more realistic.
Regards, Bauexperte
Vogtländer20 Feb 2015 21:59In our region (Saxony), a turnkey house (120m² (1,292 sq ft)) costs between €160,000 and €180,000 (standard energy-saving regulations).
I currently have an offer for a passive house of this size at €220,000, which is €40,000 more.
However, since I can get €50,000 with an interest rate of 0.75% and another €50,000 at 1.55% interest from the KfW bank, plus an additional €5,000 repayment grant and further subsidies for solar panels and battery storage, I have a saving of about €30,000 over 30 years.
This leaves additional costs of €10,000 to €20,000.
But since I save about €800–€1,000 per year on heating and even earn money from feeding electricity back into the grid thanks to the photovoltaic system and battery on the roof, I save another €1,000 annually on electricity. That’s a total saving of about €2,000 per year.
So after 10 years, the extra costs are fully recovered, and from then on, I would be making a profit compared to a standard house. Of course, there are maintenance costs here and there—let’s say 15 years to be safe. But I also have maintenance costs for a conventional heating system, which I wouldn’t need with a passive house, and a boiler would have to be replaced after 20 years anyway.
My calculations seem correct, right?!
I currently have an offer for a passive house of this size at €220,000, which is €40,000 more.
However, since I can get €50,000 with an interest rate of 0.75% and another €50,000 at 1.55% interest from the KfW bank, plus an additional €5,000 repayment grant and further subsidies for solar panels and battery storage, I have a saving of about €30,000 over 30 years.
This leaves additional costs of €10,000 to €20,000.
But since I save about €800–€1,000 per year on heating and even earn money from feeding electricity back into the grid thanks to the photovoltaic system and battery on the roof, I save another €1,000 annually on electricity. That’s a total saving of about €2,000 per year.
So after 10 years, the extra costs are fully recovered, and from then on, I would be making a profit compared to a standard house. Of course, there are maintenance costs here and there—let’s say 15 years to be safe. But I also have maintenance costs for a conventional heating system, which I wouldn’t need with a passive house, and a boiler would have to be replaced after 20 years anyway.
My calculations seem correct, right?!
Vogtländer20 Feb 2015 22:07Ok, then 800€ for heating and hot water, I think that is realistic for a standard energy saving regulation house? So it’s 15 years as mentioned. I checked again, it is even an energy-plus house for which my offer applies. So, as the building expert already said, no heating system included. I have a friend who built with this company three years ago. He needs three wheelbarrows full of wood per year for heating. His photovoltaic system produced 10,000 kWh per year, he used 3,000 kWh himself, and fed 7,000 kWh back into the grid. He had to buy 2,000 kWh when the sun wasn’t shining and the battery was empty, resulting in a net profit of 300€.
Vogtländer schrieb:
But I get €50,000 (about $54,000) from KfW at 0.75% interest and another €50,000 (about $54,000) at 1.55% interestWhy do you mention KfW twice? Or do you mean the 123 program for the first KfW loan? You need to subtract that again (which would be the better option), as this loan is available for every new build (if you want to take it). The grants also depend on the state.
Best regards, Yvonne
Vogtländer20 Feb 2015 22:22That's right, the 124 program is available for any new construction. It’s the program with 1.55% interest, which means about €5,000 less savings and it pays off after 20 years, assuming energy prices remain the same—which they probably won’t. So I’ll probably lean more towards around 15 years after all… right?!
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