We built our house on a plot given to us by my mother in law. At the time the 3 plots were all on 1 chahoot, her house, my wife's elder sister's house and our house.
When we finished building my wife went to the Amphur to register our house and get a channot issued. They wanted the original chanoot before they could do so. When she returned home we found out that the sister had taken out a loan, after we started building, and the chanoot had been lodged as security.
Needless to say I was livid

Luckily I have a few very decent brother in laws and the matter was resolved and the chanoot retrieved within a few days.
My advice to anyone building on family land is to get a chanoot for your plot before you build as afterwards you might find yourself in similar circumstances and possibly not have the happy ending that I had.
As for living on a family compound as MrCC said you are living in Thailand so don't expect too much privacy especially if you have kids.
Certainly after 7 years in the village things are much better than the early days but there are still a few family members who wander in as and when they like.