ᐅ Which type of window glazing? Double or triple glazing

Created on: 29 Jan 2016 13:10
A
AnjaBro
Hello everyone,

This question has been on our minds for a while now as we work on our new build.

We are planning to construct a KfW 70 bungalow using solid construction. The living area will be approximately 130 sqm (1400 sq ft). During the initial consultation, this topic wasn’t really addressed, but when submitting the building permit / planning permission application, we noticed that only double glazing was planned for our project. However, we have been reading increasingly that triple glazing is already considered the standard, even with our builder.

What criteria are used to determine this requirement? How can we, especially as non-experts, identify which windows are the most suitable for our needs?

Should we insist on triple glazing?

Thanks in advance.
D
Doc.Schnaggls
29 Jan 2016 14:36
Hm, that is really not much...

In our scope of work, the entire section on windows was a full A4 page and included details on the type of glazing, as well as the U-values for the glass and the entire window, frame construction, etc.

How detailed is the entire scope of work?

In my opinion, the whole construction project depends on the scope of work. You can only demand what is clearly specified there.

Statements like "quality windows from reputable manufacturers" are vague and don’t really say much...

So, I can only agree with the question from @BeHaElJa: Have you already signed the contract?
B
Bauexperte
29 Jan 2016 14:54
Hello,
AnjaBro schrieb:

We are planning the construction of a KfW 70 bungalow using solid construction. The living area will be approximately 130 sqm (1400 sqft).
In the preliminary meeting, this topic was hardly addressed; only when applying for the building permit / planning permission did we realize that "only" double glazing is planned for our project.
However, we have increasingly read that triple glazing is now considered standard, also with our builder.

To start: KfW 70 no longer exists; today there is only the Energy Saving Ordinance, KfW 55, and better. Since you are still in discussions about the building permit / planning permission, it means the application has not yet been submitted.

Without triple glazing and its professional installation, in my opinion, you will not be able to meet the requirements of the 2016 Energy Saving Ordinance. You do not have to calculate this yourself; in my opinion, you probably cannot.

However, I assume that you have already signed the construction contract. In that case, only what is stated in the contract and its annexes counts. If triple glazing is mentioned only on the website but not in the contract or annexes, you will likely only be able to obtain these better windows at an additional cost.

Best regards, Bauexperte
Y
ypg
29 Jan 2016 20:58
We have double glazing! Built in 2014, just barely missing the KfW 55 standard. And no, we don’t have skylight windows.

Maybe we pay about 100 per year more based on @BeHaElJas’s calculation? Who knows?

Extrapolating and comparing the extra cost to triple glazing, my conclusion is that we probably won’t recover the extra expense through energy savings.

So, if the house complies with the energy saving regulations for double glazing, there’s no need to worry. Otherwise, I refer you to @Bauexperte’s posts.