ᐅ KfW 40 or better in solid construction without additional insulation possible?
Created on: 18 Nov 2019 08:44
S
Specki
Hello,
I was initially set on a timber frame construction for my future house. However, I am now reconsidering solid construction because it does have its advantages. Ideally, I would prefer this without additional external insulation, as that would be redundant and insulation typically does not last as long as the masonry itself. Poroton seems the most appealing option to me at first glance.
But is that even feasible? Are there bricks (or other solid building blocks) that on their own meet the KfW 40 standard, or possibly perform even better?
Does anyone have experience with this? Has anyone actually built something like this?
I’m open to discussion if you believe additional insulation makes sense. However, no “Styrofoam” will be used on the exterior walls; if anything, it will be an alternative material.
The comments I would rather avoid are those suggesting a lower energy standard would be sufficient. I will not build anything below KfW 40.
Thanks in advance for your input.
Best regards,
Specki
I was initially set on a timber frame construction for my future house. However, I am now reconsidering solid construction because it does have its advantages. Ideally, I would prefer this without additional external insulation, as that would be redundant and insulation typically does not last as long as the masonry itself. Poroton seems the most appealing option to me at first glance.
But is that even feasible? Are there bricks (or other solid building blocks) that on their own meet the KfW 40 standard, or possibly perform even better?
Does anyone have experience with this? Has anyone actually built something like this?
I’m open to discussion if you believe additional insulation makes sense. However, no “Styrofoam” will be used on the exterior walls; if anything, it will be an alternative material.
The comments I would rather avoid are those suggesting a lower energy standard would be sufficient. I will not build anything below KfW 40.
Thanks in advance for your input.
Best regards,
Specki
A
allstar8318 Nov 2019 19:28What standard could a solid masonry house reach with:
36.5 cm (14.4 inches) Ytong blocks
Controlled mechanical ventilation with heat recovery
District heating with a primary energy factor of 0
... Would that already qualify for KFW55?
36.5 cm (14.4 inches) Ytong blocks
Controlled mechanical ventilation with heat recovery
District heating with a primary energy factor of 0
... Would that already qualify for KFW55?
Lumpi_LE schrieb:
Yes, it depends on the interpretation, but basically you’re right. I didn’t have the exact number on hand, but it’s more like 1200. That’s why it’s also the "fun" in the end. The 450 kWh (p.kWh) can be taken as a difference. It also fits with the photovoltaic system.
My electricity provider sent me an increase on Friday for January 1, 2020. It was already over 30.5 cents. So much for someone saying photovoltaic doesn’t pay off.
Bookstar schrieb:
I’m in if the payback period is under 5 years. Until then, I don’t consider it a key part of my investment strategy.
But with photovoltaics, you can’t go too wrong if you want to do it. I never saw photovoltaics as an investment with a payback period longer than 11 years anyway.
allstar83 schrieb:
What standard could a solid construction house achieve with:
36.5 cm (14 inches) Ytong blocks
Mechanical ventilation with heat recovery
District heating with a primary energy factor of 0
... Would that already be KfW55? If Ytong has a thermal conductivity (lambda) or U-value of 0.20, then yes.
My preferred wall construction would be sand-lime brick, mineral wool insulation, air space, and facing brick. It provides self-shading in the summer, offers good sound insulation, and dries out naturally.
Since you plan to do a lot yourself, I would recommend using thicker insulation for both the roof and the floor. Both should be installed using external insulation methods. The additional material costs are manageable.
With a controlled mechanical ventilation system, your heating load can be reduced to below 5 kW. Depending on the region, an air-to-water heat pump would be more than sufficient. There is also potential for savings here, depending on your level of risk tolerance.
Photovoltaic panels would always be part of my plan, but financed separately.
Since you plan to do a lot yourself, I would recommend using thicker insulation for both the roof and the floor. Both should be installed using external insulation methods. The additional material costs are manageable.
With a controlled mechanical ventilation system, your heating load can be reduced to below 5 kW. Depending on the region, an air-to-water heat pump would be more than sufficient. There is also potential for savings here, depending on your level of risk tolerance.
Photovoltaic panels would always be part of my plan, but financed separately.
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