I might want to set conditions for the house that is under my name for my girlfriend and her family
Why don't you want them involved with the house?
I don't like to spend my money with them anymore
While it's your house and you can set whatever rules you want, they are still family and it feels disconnecting to them for you to throw cold rules at them. You all need to live together and share good memories, not set boundaries like prison.
I don't care. I just want to do what I want to do.
It really is your house and your rules, but don't you want your family to feel safe and secure with you there? How do you think they'd feel having such tight restrictions onto them? How about helping to find their own place, so you can enjoy your own?