We've been living in this house for about three months now. There is a bad odor that fills the air in all 3 apartments and even outside the house occasionally. It seems like this happens when someone uses the bathroom in one of the apartments. What could be the problem?

We've been living in this house for about three months now. There is a bad odor that fills the air in all 3 apartments and even outside the house occasionally. It seems like this happens when someone uses the bathroom in one of the apartments. What could be the problem?

This could be a ruptured wax seal. It's possible for the wax seal to hold water but nhot contain the sewer gas. Have it checked. Good luck, Tom

It can also be a cracked vent pipe.

2X for wax seal.