Diffusion-open wall - no controlled ventilation needed?

Hello everyone,

this is my first post and I have many questions...

First of all, the topic of controlled ventilation.

We are planning a single-family house built with a timber frame and have received information from one of the construction companies that with their diffusion-open wall assembly, no controlled ventilation is necessary. I am unsure about this regarding the issue of mold.

According to the offer, the wall assembly from inside to outside:
9.5mm gypsum plasterboard
15mm OSB wood-based panel
200mm thermal insulation mineral fiber insulation WLG 035
200mm load-bearing wooden frame construction (KVH)
0.2mm diffusion-open climate fleece
60mm cement-bound plaster base panel
--> Exterior wall thickness including exterior plaster: approx. 304.7mm
no foils, no styrofoam, therefore diffusion-open

What do you think about this?

Thank you in advance for your opinions.

Fellina

Hello,

..First of all, the topic of controlled ventilation and exhaust. We are planning a single-family house in timber frame construction and have received information from one of the house construction companies that with their diffusion-open wall structure, no controlled ventilation and exhaust is necessary. I am uncertain about this regarding the issue of mold.

Please use the search function, there are already various posts on this topic. Controlled residential ventilation mainly offers one thing, comfort! However, it is generally not strictly necessary or even mandatory, although the opposite is often claimed. So: Have it checked by an independent party, not the seller, whether controlled residential ventilation is absolutely necessary under the specific existing conditions. Best regards.

Hello Fellina,

as €uro has already written, a controlled residential ventilation system (Kontrollierte-Wohnraumlüftung) is not strictly necessary or mandatory. In addition to a number of advantages, such as consistently good air quality (especially interesting for allergy sufferers, as it is possible to achieve a pollen-free state) in the house, controlled residential ventilation prevents moisture and mold damage, especially in new buildings (houses built to the new standard require different user behavior than existing properties, as new buildings are highly airtight compared to older buildings). At the same time, it may be necessary to have controlled residential ventilation in order to meet certain building standards and to receive attractive subsidies from the KfW. Of course, the installation of controlled residential ventilation involves a certain investment budget, depending on the size of the building.

Regarding the chosen wall construction, it should be considered to use cellulose. An advantage of cellulose, which is blown into the timber frame construction, is, among other things, the increase of summer heat protection. Mineral fiber insulation materials have only a low heat storage capacity, so the heat generated by solar radiation quickly passes through the building material. Basically, it should be noted that it is nice when it is warm in winter, but it must also be ensured that temperatures do not become too high in summer. If necessary, cooling must then be used, and thus the energy saved in winter is wasted in summer.

Regards