ᐅ Building to the Energy Saving Ordinance 2016 or to KfW55 standards
Created on: 16 Jun 2021 13:08
R
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
N
nordanney7 Jul 2021 16:46hampshire schrieb:
A sheet of paper is airtight with respect to airflow, but not with respect to moisture transport. Which kind of "airtight" do you mean?He means both. The difference in masonry might be about 1% between "poorly breathable" and "breathable" masonry (where masonry means monolithic masonry, timber frame house, ETICS, etc.). So instead of 1–2% of the indoor humidity being released through the "poor" wall, 2–3% is released through the "breathable" wall. But this doesn’t really matter, since 97% or 98% is effectively the same, as most moisture escapes through ventilation.N
nordanney7 Jul 2021 21:36Zaba12 schrieb:
Someone still needs to mention that walls without external thermal insulation composite systems (ETICS) can breathe I just came from my renovation site. I listened closely. The walls even creaked because an ETICS is going to be applied and they are afraid of suffocating 😉
H
hampshire9 Jul 2021 09:14There is a reason why some people feel very comfortable in certain houses while others find them “stuffy.” This relates both to the behavior of the occupants and to building physics. The wall construction and the connection of different materials to each other (regardless of which) as well as the technology used for temperature and humidity control all play a significant role. Reducing the discussion to a single building material (wood or masonry) is as simplistic as focusing solely on “airtightness.”
What I find problematic is this oversimplification combined with the fundamental claim that “everything else is nonsense.”
Certainly, both sides use metaphors that work better or worse. Referring to the process in which a material balances moisture by absorbing it and then releasing it back into the room (not through the wall to the outside) as “breathing” is a useful analogy, although literally it is clearly nonsense.
What I find problematic is this oversimplification combined with the fundamental claim that “everything else is nonsense.”
Certainly, both sides use metaphors that work better or worse. Referring to the process in which a material balances moisture by absorbing it and then releasing it back into the room (not through the wall to the outside) as “breathing” is a useful analogy, although literally it is clearly nonsense.
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