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.
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.Schnaggls29 Jan 2016 13:25Hello,
well, triple glazing simply offers better thermal insulation than double glazing.
As you mentioned, triple glazing is now standard with many suppliers.
However, it’s not just about the glass itself; the design of the frames and fittings also plays an important role in insulation as well as burglary protection.
Insisting on triple glazing (without an additional cost) could be difficult – what does your building specification say about windows?
Regards,
Dirk
well, triple glazing simply offers better thermal insulation than double glazing.
As you mentioned, triple glazing is now standard with many suppliers.
However, it’s not just about the glass itself; the design of the frames and fittings also plays an important role in insulation as well as burglary protection.
Insisting on triple glazing (without an additional cost) could be difficult – what does your building specification say about windows?
Regards,
Dirk
Question about the additional cost. Assuming you have 40 m² (430 ft²) of windows and the U-value improves from 1.3 to 0.8 W/m²K, is it worth it over 20 years if the extra cost does not exceed approximately €1900?
0.5 W/m²K * 40 m² (430 ft²) * (13.1°K (23.6°F) * 210 days * 24h) = 1320 kWh -> €92 per year -> €1850 over 20 years.
Explanation of the bracket: 7 months during which the average maximum temperature in Germany stays below 15°C (59°F), averaging 6.9°C (44.4°F). Indoor temperature assumed to be 20°C (68°F) -> temperature difference of 13.1°K (23.6°F).
For a more accurate calculation, use your building’s geometry/energy performance certification documents and enter the data into u-wert.net, then change the window U-value.
For example, we have 47.66 m² (513 ft²) of windows with triple glazing and a total heating demand of 7153 kWh/year. If I replace the windows with double glazing, I end up with 8480 kWh/year -> 1327 kWh/year -> €92 per year (gas).
0.5 W/m²K * 40 m² (430 ft²) * (13.1°K (23.6°F) * 210 days * 24h) = 1320 kWh -> €92 per year -> €1850 over 20 years.
Explanation of the bracket: 7 months during which the average maximum temperature in Germany stays below 15°C (59°F), averaging 6.9°C (44.4°F). Indoor temperature assumed to be 20°C (68°F) -> temperature difference of 13.1°K (23.6°F).
For a more accurate calculation, use your building’s geometry/energy performance certification documents and enter the data into u-wert.net, then change the window U-value.
For example, we have 47.66 m² (513 ft²) of windows with triple glazing and a total heating demand of 7153 kWh/year. If I replace the windows with double glazing, I end up with 8480 kWh/year -> 1327 kWh/year -> €92 per year (gas).
@Doc.Schnaggls:
The specification document for the construction work mentions the following about the windows:
Unfortunately, there is no mention of the type of window used.
The standard of triple glazing is stated directly on their website.
We are now quite unsure.
Is there any way to determine ourselves which option would be better?
The specification document for the construction work mentions the following about the windows:
Unfortunately, there is no mention of the type of window used.
The standard of triple glazing is stated directly on their website.
We are now quite unsure.
Is there any way to determine ourselves which option would be better?
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