Construction costs are currently skyrocketing

In many installations there are then meter-long, moderately well insulated cold air ducts from air intake/outlet to the controlled residential ventilation in the house. This leads to additional losses; with 6m of pipes, the heat recovery rate already drops from 0.9 to an effective 0.5.

There are questions left open for me. Heat recovery rate from 0.9 to 0.5, i.e. the constant heat loss is 10-50%? I cannot ventilate as intensively without controlled residential ventilation, because then I only push warm air out and after 15 minutes the room has the initial temperature again, since everything is still warm.

There are questions open for me. Heat recovery rate from 0.9 to 0.5,

That is simply the surface area of the pipes times the U-value of the pipes times the temperature difference between cold air inside the pipe and warm air outside. For outside air and supply air. That results in a considerable heat transfer. But now it really gets too much off topic, how are the current prices and availability of Zehnder controlled residential ventilation systems?

That’s why aluminum-laminated mineral wool is applied there (and Armaflex at the critical points because of condensation). Almost no one does that.

We would also have liked to have a controlled residential ventilation system with a heat exchanger in our semi-detached house (143m2+basement, developer).... but I would rather invest €14,500 in more photovoltaics, it is simply too expensive (my opinion). And the offer did not come from the developer, but directly from the installer. The other items were also not cheap, but acceptable. Therefore, I do not believe that the price for the controlled residential ventilation system was significantly above the current price level.

If I had had the time, I would have liked to install a central controlled residential ventilation system in my home. Especially with two working residents, airing out is generally difficult. Besides insulating the pipes, a so-called air well is also very helpful. It only costs a few meters of pipe and can be done very well by yourself. Nowadays, of course, all this is rather dispensable if you have to save money. Personally, I do not expect prices to decrease again. Dealers are relying on the habituation effect. There will now be a phase in which only the truly high earners can build a house. Those who earn a moderate income will have to get used to renovating affordable existing properties through their own efforts. Otherwise, nothing will be possible anymore.

Personally, I do not expect prices to fall again. The dealers are relying on the habituation effect. There will now be a phase in which only the truly high earners can build a house.
Those who earn a mediocre income will have to get used to the fact that they renovate affordable existing properties through their own efforts. Otherwise, nothing will be possible anymore.

In my view, this is contradictory. On the one hand – an absolutely overbuilt construction industry at maximum size with a dissolving backlog, and on the other hand a dramatic drop in demand with only a few remaining, but very solvent, customers. It is unlikely that the numerous margin cushions can be maintained there.