ᐅ Exterior Wall for KfW 40 (+) Standard: With or Without External Thermal Insulation Composite System (ETICS)?
Created on: 18 Feb 2021 11:23
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Franke86
Hi everyone,
I need some advice. I’m currently planning my detached single-family house. The developer’s standard offering includes 24 hollow bricks plus 14 cm (5.5 inches) external wall insulation (EWI).
Since I want to build to KfW 40 (Plus) standard, they told me I would need 24 hollow bricks plus 18 cm (7 inches) EWI, which would cost an additional €1800.
What would you recommend? Is using EWI still considered "up-to-date," or is it becoming less common?
One advantage mentioned to me is that this creates a cavity wall construction, which offers better insulation and should also help prevent mold.
I also wanted to get some pricing for purely monolithic walls, and I received the following offer (standard is 24 hollow bricks + 14 cm (5.5 inches) EWI):
Which option would you choose, and are these additional costs typical or too high?
Brief details about the house: It’s a detached single-family home with a flat roof, approximately 160 sqm (1722 sq ft) living area, a ventilation system with heat recovery, and district heating for the heating.
Best regards,
Franke86
I need some advice. I’m currently planning my detached single-family house. The developer’s standard offering includes 24 hollow bricks plus 14 cm (5.5 inches) external wall insulation (EWI).
Since I want to build to KfW 40 (Plus) standard, they told me I would need 24 hollow bricks plus 18 cm (7 inches) EWI, which would cost an additional €1800.
What would you recommend? Is using EWI still considered "up-to-date," or is it becoming less common?
One advantage mentioned to me is that this creates a cavity wall construction, which offers better insulation and should also help prevent mold.
I also wanted to get some pricing for purely monolithic walls, and I received the following offer (standard is 24 hollow bricks + 14 cm (5.5 inches) EWI):
- T9 brick, thickness = 36.5 cm (14.4 inches) + €900
- 0.09 aerated concrete block, thickness = 36.5 cm (14.4 inches) + €900
- Hollow brick + 18 cm (7 inches) EWI = KfW 40+ compliant => + €1800
- T9 brick, thickness = 42.5 cm (16.7 inches) = ? KfW 40+ compliant => + €7000
- 0.09 aerated concrete block, thickness = 42.5 cm (16.7 inches) = ? KfW 40+ compliant => + €7000
Which option would you choose, and are these additional costs typical or too high?
Brief details about the house: It’s a detached single-family home with a flat roof, approximately 160 sqm (1722 sq ft) living area, a ventilation system with heat recovery, and district heating for the heating.
Best regards,
Franke86
haydee schrieb:
Nothing will follow the Passive House standard anytime soon.Actually, there is already something, the Plus Energy House, of which there are already several examples. The topic of energy, heat, electricity, and storage is far from being finished, for example, home power solutions with the Picea system for single-family houses.W
WilderSueden19 Feb 2021 23:27Calculated positive energy houses are on a different scale. With appropriately sized photovoltaic systems, it is possible to generate more energy in summer than is needed in winter for a house built to energy saving standards. However, this is of limited practical use.
True positive energy houses (in the sense that they could operate entirely off the grid) currently exist only as demonstrations or novelty projects for the wealthy. Storing summer energy for winter use, for example through hydrogen, is neither economically viable nor practical. Economies of scale will make grid-scale storage significantly cheaper than having individual hydrogen storage systems in basements, which are increasingly rare.
True positive energy houses (in the sense that they could operate entirely off the grid) currently exist only as demonstrations or novelty projects for the wealthy. Storing summer energy for winter use, for example through hydrogen, is neither economically viable nor practical. Economies of scale will make grid-scale storage significantly cheaper than having individual hydrogen storage systems in basements, which are increasingly rare.
You carbon units obviously have never seen The Matrix, even though the movie is already 20 years old.
Technological development over the past 50 years has been rapid, and it is accelerating even faster. Some people feel left behind and overwhelmed, longing for a halt to this unstoppable progress; there is another thread about that topic here at the moment.
In 50 years, there will be things (and needs) that we cannot even imagine today.
Technological development over the past 50 years has been rapid, and it is accelerating even faster. Some people feel left behind and overwhelmed, longing for a halt to this unstoppable progress; there is another thread about that topic here at the moment.
In 50 years, there will be things (and needs) that we cannot even imagine today.
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I will inquire about the cost of calcium silicate and 20cm (8 inches) ETICS..
Or I will definitely use calcium silicate inside... and maybe Poroton or aerated concrete on the outside.
guckuck2 schrieb:
Exchanging arguments leads to discussion. That is usually what a forum is for.
And I'm not telling "you" how to fix things, but everyone. Because "nails don’t hold well in external thermal insulation composite systems (ETICS)" is undoubtedly true, but I would argue that nails are always a poor choice, barely acceptable in wood, especially on facades.
By the way, chewing gum doesn’t stick well to glass.
One should follow the example of @11ant – don’t force anyone to use materials they are not (well) familiar with. That only causes trouble.
Read the last 10 pages, then you can form your own opinion 😀
Without overanalyzing it, this still seems reasonable. Besides the extra costs for thicker insulation, you’ll need deeper window sills and coping sheets.
Very good. Always choose a solid flat roof and definitely not one made of wood!
That’s probably what our ancestors thought 50 years ago. Energy was free.
Who knows what will change in another 50 years.
17.5cm (7 inches) calcium silicate brick plus 20cm (8 inches) insulation should be a suitable combination for the original poster, making 37.5cm (15 inches) for a KfW 40 building envelope.
I did criticize the unnecessary thickness of the hollow clay brick; calcium silicate performs better here. But the elephant rule still applies as above.
I will inquire about the cost of calcium silicate and 20cm (8 inches) ETICS..
Or I will definitely use calcium silicate inside... and maybe Poroton or aerated concrete on the outside.
And if the structural builders have no experience with calcium silicate bricks, then using perforated clay bricks plus ETICS (external thermal insulation composite system) will not be a mistake either. If soundproofing is important to you, then pay attention to the windows. It won’t help much if you end up installing windows with a sound insulation value of only 32dB 🙂
Baranej schrieb:
And if the masons have no experience with sand-lime bricks, then using perforated bricks plus external wall insulation will also be a safe choice. If sound insulation is a major concern for you, then pay attention to the windows. It won't help much if you install windows with only a 32 dB sound reduction rating in the end 🙂I agree with you on that.Similar topics