ᐅ Old Building with New Windows: How to Install Additional Ventilation?
Created on: 15 Jun 2017 17:45
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Altbau1930A
Altbau193015 Jun 2017 17:45Hello,
On Tuesday, our energy consultant visited our house to inspect it. He is supposed to plan the roof insulation and provide specifications for the new windows.
The good news first: The consultant is a trained carpenter, and after inspecting the rafters, he said the roof structure is completely fine except for a small beam. This is contrary to the opinion of the expert surveyor, who believed the woodworm had caused significant damage. The energy consultant did not confirm this; only one beam had been affected by woodworm at some point, but no wood debris has been found on the floor in recent years. In short: the roof will be re-covered and insulated, but the (expensive) roof structure can be preserved.
On Monday, the energy consultant will come with a roofer to plan the roof, which should ultimately meet KfW standards and be eligible for funding.
The same applies to the windows; we already have an estimate, but it’s for double glazing. The consultant recommends triple glazing, which will not be significantly more expensive.
However, since we do not want to insulate the walls, the consultant said mold will definitely develop after installing new windows. This must be avoided.
There are two options:
- Install ventilation in each room through the external wall. This means core drilling and installing vents (the less desirable option, probably expensive and complicated).
- Install windows with integrated ventilation (which sounds interesting).
How have you solved the problem of mold formation after new windows, and what type of ventilation do you have?
I would be grateful for any advice!
On Tuesday, our energy consultant visited our house to inspect it. He is supposed to plan the roof insulation and provide specifications for the new windows.
The good news first: The consultant is a trained carpenter, and after inspecting the rafters, he said the roof structure is completely fine except for a small beam. This is contrary to the opinion of the expert surveyor, who believed the woodworm had caused significant damage. The energy consultant did not confirm this; only one beam had been affected by woodworm at some point, but no wood debris has been found on the floor in recent years. In short: the roof will be re-covered and insulated, but the (expensive) roof structure can be preserved.
On Monday, the energy consultant will come with a roofer to plan the roof, which should ultimately meet KfW standards and be eligible for funding.
The same applies to the windows; we already have an estimate, but it’s for double glazing. The consultant recommends triple glazing, which will not be significantly more expensive.
However, since we do not want to insulate the walls, the consultant said mold will definitely develop after installing new windows. This must be avoided.
There are two options:
- Install ventilation in each room through the external wall. This means core drilling and installing vents (the less desirable option, probably expensive and complicated).
- Install windows with integrated ventilation (which sounds interesting).
How have you solved the problem of mold formation after new windows, and what type of ventilation do you have?
I would be grateful for any advice!
If window replacement is to qualify for KfW funding as a standalone measure, the wall’s U-value must not be lower than that of the window. This needs to be verified, as otherwise there is indeed a risk of condensation buildup and mold growth on particularly cold parts of the uninsulated exterior wall. Your energy consultant should be aware of this, especially if they apply for and oversee KfW measures as a qualified expert.
When replacing windows, a ventilation concept according to DIN 1946-6 must also be created. The required air exchange rate can, for example, be achieved through a decentralized ventilation system. Alternatively, so-called trickle vents installed in the window frame may be sufficient. This must be demonstrated through calculations.
You will need an energy consultant who develops a comprehensive renovation concept for the entire building. All measures must be coordinated and aligned at the interfaces.
When replacing windows, a ventilation concept according to DIN 1946-6 must also be created. The required air exchange rate can, for example, be achieved through a decentralized ventilation system. Alternatively, so-called trickle vents installed in the window frame may be sufficient. This must be demonstrated through calculations.
You will need an energy consultant who develops a comprehensive renovation concept for the entire building. All measures must be coordinated and aligned at the interfaces.
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Altbau193015 Jun 2017 22:03Thank you so far!
The windows do not necessarily have to be included in the KfW measure (it would be nice, but the roof definitely should), yet we still want to prevent mold growth. I need to speak with the window company tomorrow to find out if they offer suitable ventilated models, and if so, the energy consultant should take a look. Alternatively, they can suggest other options.
The windows do not necessarily have to be included in the KfW measure (it would be nice, but the roof definitely should), yet we still want to prevent mold growth. I need to speak with the window company tomorrow to find out if they offer suitable ventilated models, and if so, the energy consultant should take a look. Alternatively, they can suggest other options.
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