8 month old puppy has started peeing on my bed and everywhere else?

We have an almost 8 month old lhasa apso shitz shu cross, he was relatively easy to house train since we have a dog door and he could go out into the yard when ever he wanted. He is not allowed in the living room most of the time because he would pee on the floor and I can't seem to get it through his head that he can't pee in there, he will do it right in front of us like he doesn't think anything is wrong and we have to keep the gate closed so the baby doesn't take off down the hall way and out the dog door. So anyway keeping out of the living room other then for awhile in the morning and then again at night after my daughter is bed seemed to solve the peeing in the house problem he never peed anywhere else until about a month ago when he started peeing on our bed, I caught him in the act and corrected him and put him outside, after that for 2 days we locked him out of our room at night and then he went for 2 weeks with no problems ( I figured he learnt not to do it) Now a couple of days ago he was in the living room and just hopped up on the kids foam couch and peed all over it, and last night he peed on my bed again. I don't know what to do here, he is a sweet little puppy but I'm at the end of the leash here. any suggestions?