Hey,
our neighbors with 3 boys (real little rascals...) first tried whether the youngest would fit through. Result: he fit! :)
Something else; how do you make the shaft soundproof? In our utility room, the heating, the ventilation system, and what feels like the washing machine and dryer three times a day make noise. I wouldn’t want that noise in the upstairs area...
Best regards,
Andreas
No problem at all if done properly. Definitely build it up with masonry and then use KG pipe. Proper insulation in between. Also, there must be a lid at the bottom and top. The one at the bottom with a spring or weight so that it is self-closing.
Such a construction costs about 500 euros in materials if you do it yourself. If you hire someone to do it, you’re looking at about 2,500 - 4,000 euros.