ᐅ Double or triple glazing in new construction – triple glazing allegedly an unnecessary expense
Created on: 23 Sep 2022 09:54
S
Smeagol
Hello everyone,
The window salesperson/advisor recommended using double glazing with a U-value of 0.81 instead of triple glazing with a U-value of 0.6 for our new build at KFW60 standard.
The additional cost for the nearly 17 windows and patio doors totals around 3,000 EUR.
They explained that triple glazing reduces solar heat gain (which makes sense due to light refraction and so on), but still suggested that the extra expense might not be worth it. Online, I found a break-even point of about 10 years for the additional cost of triple glazing.
What’s your assessment?
Thanks!
The window salesperson/advisor recommended using double glazing with a U-value of 0.81 instead of triple glazing with a U-value of 0.6 for our new build at KFW60 standard.
The additional cost for the nearly 17 windows and patio doors totals around 3,000 EUR.
They explained that triple glazing reduces solar heat gain (which makes sense due to light refraction and so on), but still suggested that the extra expense might not be worth it. Online, I found a break-even point of about 10 years for the additional cost of triple glazing.
What’s your assessment?
Thanks!
S
SaniererNRW12323 Sep 2022 12:03Smeagol schrieb:
Ok, ok, there was probably some confusion regarding the Uw and Ug values, sorry about that. No problem at all. That’s why you’re here—to get information.
Smeagol schrieb:
I specifically mentioned the KfW60 standard because the house’s energy consumption is at that level. KfW 60 will no longer be approved next year. So you won’t be able to build to that standard and will need to invest any savings elsewhere, such as on the windows, if possible.
Apart from that, double glazing for a new build is about as outdated as an old gasoline engine from the 1990s. It’s no longer state of the art. I would never consider using such windows in a new build, even if they might technically meet the requirements.
Smeagol schrieb:
On the contrary: I was actually fully convinced to go with triple glazing, but the consultant himself said it doesn’t make much of a difference overall. I was quite surprised by that. It doesn’t really make that much difference—KfW 55 is still KfW 55. You just lose more energy through the windows and less through the building envelope. But with windows, especially large units, you definitely feel the cold that comes through.
SaniererNRW123 schrieb:
KfW 60 never existed.Strange, I live in one.Is this like the Bielefeld conspiracy? 😀
S
SaniererNRW12323 Sep 2022 13:39driver55 schrieb:
Strange, I live in one.
Is this like the Bielefeld conspiracy? 😀 Maybe I should have said: It hasn’t existed for over 10 years 😉
Here are a few more details.
Double glazing: glass has a Ug value of 1.1 --> Uf = 1.20
Triple glazing: glass has a Ug value of 0.6 --> Uf = 0.89
Thanks very much for the quick feedback!
PS: Do these Swissspacers make sense? Do they reduce the Uf values by about 0.02 each?
PPS: The building permit / planning permission was applied for this year, so the requirements are still moderate according to the energy saving regulations, aka KFW70 as the minimum specification. ;-)
Double glazing: glass has a Ug value of 1.1 --> Uf = 1.20
Triple glazing: glass has a Ug value of 0.6 --> Uf = 0.89
Thanks very much for the quick feedback!
PS: Do these Swissspacers make sense? Do they reduce the Uf values by about 0.02 each?
PPS: The building permit / planning permission was applied for this year, so the requirements are still moderate according to the energy saving regulations, aka KFW70 as the minimum specification. ;-)
I think considering double glazing on the south side (which could also make sliding doors easier to operate) is definitely a reasonable option, but it should be evaluated on a case-by-case basis.
I see it differently; see also "Are three window panes better than two?" (not linkable here, but easy to find with quotation marks). I also recommend the related post on the topic of "warm edge," in which...
... is mentioned, although not yet discussed. The term is probably a registered trademark – I have not researched how extensively the concept is patented. But I do not consider it a groundbreaking reinvention.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
SaniererNRW123 schrieb:
Apart from that, double glazing for a new build is about as outdated as an old petrol engine from the 90s. Not state of the art anymore.
I see it differently; see also "Are three window panes better than two?" (not linkable here, but easy to find with quotation marks). I also recommend the related post on the topic of "warm edge," in which...
Smeagol schrieb:
Swissspacer
... is mentioned, although not yet discussed. The term is probably a registered trademark – I have not researched how extensively the concept is patented. But I do not consider it a groundbreaking reinvention.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
Smeagol schrieb:
Here are a few more details.
Double glazing: glass has a Ug value of 1.1 --> Uf = 1.20
Triple glazing: glass has a Ug value of 0.6 --> Uf = 0.89
Thanks very much for the quick feedback!
PS: Do these Swissspacers make sense? They reduce the Uf values by about 0.02 each.
PPS: The building permit / planning permission was applied for this year, so the energy saving regulations are still moderate, with KFW70 as the minimum specification. ;-) Here is your answer. Especially for larger surface areas, the glass accounts for a larger percentage than the frame. Choose triple glazing.
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