Downpipe outside the upper floor exterior wall but inside the ground floor corner - sound insulation

Upload the WHOLE plan, not just the one part that seems questionable to you. Usually, such parts are just the tips of icebergs.

Hello Jootree

there are special, soundproofed pipes for wastewater. Quite thick walls. They cost a bit more. I have those in the basement. You hardly hear anything, even though they are exposed.

Steven

What kind of pipes are those then, cast pipes?

What kind of pipes are those then, cast iron pipes?

Hello They are made of plastic. Just google it. Steven