There is a standard, Sound Transmission Class [1]. STC-50 is generally considered to be a good level of sound isolation. I have no idea if houses are commonly c

There is a standard, Sound Transmission Class [1]. STC-50 is generally considered to be a good level of sound isolation. I have no idea if houses are commonly constructed with a concern for this rating though. [1]: https://en.wikipedia.org/wiki/Sound_transmission_class https://en.wikipedia.org/wiki/Sound_transmission_class