That sounds more like a old/cheap construction problem than a shared walls problem. I live in an apartment with solid concrete walls built in the 80s and I never hear my neighbours unless they are full-on screaming, which I’ve only heard happen once.

15-20 min is too far, if it is going to have any impact, the distance to the closest bus stop can’t be any further from houses than 10 min.

The sound is bad enough but with properly constructed walls, it’s not a problem.

I have other problems with shared walls. Your neighbors have cockroaches? Now you do too! Bedbugs? Yep those can come on in too. If you live in an apartment, then you bet the landlord will cheap out and not do as effective treatments. You think being clean and not keeping things in cardboard will stop them? Maybe temporarily but they’re just waiting to come back out from the walls where they weren’t treated. Joy!

The other thing is that if your neighbor smokes cigarettes inside, then you get some bonus secondhand smoke. If you have bad reactions even with allergy medications and HEPA filters, well I guess it’s time for you to move or suffer. (You didn’t want to use your PTO on anything not sick days right?)

Did your neighbors have a plumbing problem that they neglected? Congratulations on your new mold in your shared walls. (You wanted to call code enforcement on your landlord about this? Good luck, they won’t enforce it.)

I’m sure there are real solutions to my above problems but my reality is that the only solution is to move when it’s too much to bear. (Haven’t lived in one place for more than 2 years because of it…)

Don’t build your houses out of cardboard then