ᐅ Building to the Energy Saving Ordinance 2016 or to KfW55 standards
Created on: 16 Jun 2021 13:08
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Raiweired
Hello,
I have been following the forum for a few weeks and have an important question before signing the fixed-price contract.
I am building a turnkey city villa (catalog home) with an air-to-water heat pump, living area approximately 118 sqm (1272 sq ft), and the planning contract has already been awarded. The general contractor offers a standard build according to the Energy Saving Ordinance 2016 and charges an additional approximately 13,000.00 Euro for upgrading to KfW55 standards, which includes improved insulation under the slab and ceiling above the upper floor, as well as exchanging Poroton T12 bricks for Poroton T9 bricks.
The subsidy for KfW55 is 18,000.00 Euro, and the subsidy for KfW55 EE is up to 26,250.00 Euro.
If I build to KfW55 standards, I expect additional costs of 13,000.00 Euro for the improved insulation, 2,000.00 Euro for the energy consultant, and 10,000.00 Euro for a decentralized ventilation system. That would use up the subsidy entirely. According to my research, the annual savings in electricity costs for the air-to-water heat pump compared to the Energy Saving Ordinance 2016 are only about 100.00 Euro per year.
Of course, the higher market value potentially achieved when selling the house speaks in favor of KfW55, but I do not plan to sell.
Otherwise, the savings compared to the Energy Saving Ordinance 2016 to KfW55 are only marginal. Additional ventilation also brings maintenance costs. With KfW55, the building envelope is sealed so tightly that fresh air must be supplied again via fans. You pay for the increased insulation and then for the ventilation needed to compensate. Houses built to the Energy Saving Ordinance 2016 are not as airtight and do not require ventilation systems.
I am opening this topic for discussion.
I look forward to hearing the various opinions.
Regards, Raiweired
I have been following the forum for a few weeks and have an important question before signing the fixed-price contract.
I am building a turnkey city villa (catalog home) with an air-to-water heat pump, living area approximately 118 sqm (1272 sq ft), and the planning contract has already been awarded. The general contractor offers a standard build according to the Energy Saving Ordinance 2016 and charges an additional approximately 13,000.00 Euro for upgrading to KfW55 standards, which includes improved insulation under the slab and ceiling above the upper floor, as well as exchanging Poroton T12 bricks for Poroton T9 bricks.
The subsidy for KfW55 is 18,000.00 Euro, and the subsidy for KfW55 EE is up to 26,250.00 Euro.
If I build to KfW55 standards, I expect additional costs of 13,000.00 Euro for the improved insulation, 2,000.00 Euro for the energy consultant, and 10,000.00 Euro for a decentralized ventilation system. That would use up the subsidy entirely. According to my research, the annual savings in electricity costs for the air-to-water heat pump compared to the Energy Saving Ordinance 2016 are only about 100.00 Euro per year.
Of course, the higher market value potentially achieved when selling the house speaks in favor of KfW55, but I do not plan to sell.
Otherwise, the savings compared to the Energy Saving Ordinance 2016 to KfW55 are only marginal. Additional ventilation also brings maintenance costs. With KfW55, the building envelope is sealed so tightly that fresh air must be supplied again via fans. You pay for the increased insulation and then for the ventilation needed to compensate. Houses built to the Energy Saving Ordinance 2016 are not as airtight and do not require ventilation systems.
I am opening this topic for discussion.
I look forward to hearing the various opinions.
Regards, Raiweired
I am not personally working in the construction industry and am sharing information based on what our architect and energy consultant have told me.
The link explains what a vapor barrier/vapor retarder is and when it is used. It may be possible to build without a membrane at all, but since airtightness was not a priority for us, we did not look into alternatives.
The link explains what a vapor barrier/vapor retarder is and when it is used. It may be possible to build without a membrane at all, but since airtightness was not a priority for us, we did not look into alternatives.
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nordanney7 Jul 2021 14:44mete111 schrieb:
The link explains what a vapor barrier/vapor retarder is and when it is used.I’ll summarize the link (since it will be deleted because links are not allowed).- Vapor... is needed in roofs
- Vapor... is needed with interior insulation
I didn’t read anything about new buildings with ETICS or similar systems.
You will have also installed a membrane in your roof 😉 .
mete111 schrieb:
but since vapor tightness was not desirable for usBut you are building airtight! This is the requirement for KfW 55 standard. You have to comply with it just as if your house had a membrane. There is no difference!
Don’t let anyone fool you (and that is nonsense) that your house is not airtight. If it were not airtight, it would not be a KfW 55 house and you could only dream of the subsidy, and nothing more.
This is stated in the Building Energy Act (the values were identical in the Energy Saving Ordinance):
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hampshire7 Jul 2021 14:49Some houses make you feel like you’re living in a plastic container, and others don’t. We experienced that “plastic container feeling” in 9 out of 10 model homes in the typical show home estates. Whatever criteria you use to define it – like @mete111, we wanted to avoid that feeling. Apparently, we received good advice, chose not to strictly follow the KfW standards, and ended up with a successful result. Vapor barriers or airtightness aside.
The example from @mete111 is once again a perfect demonstration of the nonsense people are often told.
Whether concrete, aerated concrete blocks, bricks, timber framing, etc., all houses are equally airtight; the only real difference is basically the factor of "poor workmanship."
Whether concrete, aerated concrete blocks, bricks, timber framing, etc., all houses are equally airtight; the only real difference is basically the factor of "poor workmanship."
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hampshire7 Jul 2021 16:13halmi schrieb:
Whether concrete, aerated concrete blocks, bricks, timber frame, etc., the houses are all equally airtight; the only real difference is basically the factor of "poor workmanship during construction".A sheet of paper is airtight in terms of air flow, but not in terms of moisture transport. Which kind of "airtight" do you mean? With this oversimplification, you won’t be able to prove others wrong for "talking nonsense." Building physics is a bit more complex than that, I’m afraid.
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