Old building with new windows: how to create additional ventilation?

Hi,

this will be decided on Friday when the energy consultant has inspected the window recesses in the house.

There will be plastic windows with triple glazing from the company Oliplast.

For the roof, we will decide on aluminum or metal in slate look and color, as this material weighs only one tenth of a slate roof, which benefits the old beams (the beams are okay). In addition, this material including insulation is quite affordable.

In advance, the energy consultant advised to at least make a borehole through the exterior wall with a duct and a small fan in the bathroom and also the bedroom (rooms with high humidity values), so that these rooms can actively breathe and thus prevent mold.

Today's windows are so tight that in old buildings they always promote mold if no countermeasures are taken.

...What speaks against multiple daily shock ventilations?

In the bathroom, I can still imagine a fan controlled over time, but buying airtight windows and then installing a leak is more than questionable.

The window rebate vents like RegelAir are a poor compromise even with a ventilation system.

If a ventilation system is planned, then with heat recovery.

Current status:

In the wet area (bathroom), an exhaust vent to the outside is to be installed. Window rebate ventilation will be added in various rooms. The windows are now ordered and in planning, and are expected to be installed around February.

I will contact the energy consultant tomorrow and clarify the details. Rails are also to be installed on the inside of the window reveals in the corners so that condensation water can drain(?). Additionally, a thin insulation layer must be placed under the new interior window sills (which will probably be made of wood).

With the window rebate ventilators and the exhaust air in the bathroom, you are unlikely to have problems with condensate. Thank you for the update

Yes, but I need to see which exhaust system it will be. It should be quick to disassemble and quick to clean. Mold may possibly form there.

I would prefer an exhaust going upwards through the roof (with HT pipes), if that is technically possible at all. The roof is going to be redone anyway, and so the connection could be made there, and I would save myself the core drilling through the wall. Let's see what the energy consultant suggests.