after moving in, my family and i found out that the plumbing / pipes on the first floor bathrooms were prone to leaking.

although we did some preliminary checks - such as flooding in the toilet- it wasn't until we moved in and started using the bathrooms frequently that it started to leak significantly.

another area to look out is the sealing to the window panes / glass sliding doors. the sealing and rubber strips tend to be loosely fitted / the whole frame loosely fitted.