Hi @Bgirl11
Hi and welcome to the forums.
From what I understand people with BPD have a lot of difficulty regulating their emotions and have intense mood swings between calm and rage. They do not understand the impact their emotions have on loved ones. Sadly, they often end up on their own as people find their fluctuating emotions and other behavioural issues too hard to handle.
Finances are often not the issue when it comes to home repairs. People with personality disorders will often only act on something when it impacts them, some do not like paying others for jobs they can DIY (which they often do badly). If finances are the problem, then offering to pay for the repairs might be an option which may or may not be acceptable to his Dad.
Whilst it goes against the grain of what is considered to be a basic requirement in a house, at the end of the day, the house belongs to Dad.
Seeing a counsellor and learning how to set and enforce boundaries is often the best course of actions for loved ones.
Moving out might be the choice your fellow needs to make if conditions are not acceptable unless Dad specifically wants son to live with him, in which case he might have some leverage to say he will only do so if plumbing fixed - and move out until such time as it is.
"Stop walking on eggshells" is a book that is often recommended on this forum to help loved ones of those with BPD.
