Ventilation duct installation shaft

hello,

unfortunately, I am currently reaching my limits regarding the installation shaft planning for the controlled residential ventilation ducts. I did not expect that my general contractor wants to divert a piece of the hallway for this, namely DD 80x20, please see the attachment, which would cause space losses where it is already tight and an ugly piece of wall in the hallway.

The same applies to the kitchen DD 70/20 for the bathroom installation. How is something like this optimally solved? I would be very grateful for suggestions and ideas!

Thank you!

Do you doubt the necessity of installation shafts?
Are you building with a basement?

Best regards, Yvonne

No, not regarding the necessity but regarding the best possible solution with minimal space losses. Yes, we are building with a basement and an upper floor.

For that, one would need to see the overall picture (the complete draft planning). Ideally, one would probably try to get by with one shaft and then distribute horizontally on each floor.

What does the planner say?

The planner is also the manufacturer, it is a Zehnder Q350, originally the shaft was along the wall next to the shower on the ground floor, but there is no space for a shaft there, unfortunately it is too small. The plan is a ceiling breakthrough at D 80/20 from the upper floor to the ground floor and then the basement, and the question now is where and how it can be optimally positioned in the room? Does it have to be 80 cm x 40 cm or could it be, for example, 100 x 20 cm to realize a narrower shaft? How have you solved this in your case and what corresponds here to the state of the art?

I find the space occupied by a shaft or two to be absolutely negligible in relation to a living area. Half a square meter for 50 sqm is just 1%. One should simply let the professional do it and come to terms with it – there are much more important things in house construction that can make your hair turn gray.

Besides, the place where it is marked seems to be a good spot: the niche as a wardrobe space is not noticeably reduced.

In short, best regards