Honestly, I think I'm a freak because I paint my house every year. I have been talking to everyone and they say they don't paint that often. So how often should I paint? I usually do it as a part of my spring cleaning.
I have to do touch ups every year, I usually do it in the spring when I do my spring cleaning. I only do major painting if it is starting to look really bad or when I get the itch to redecorate my house.
I think different houses need different maintenance levels. It also depends on the location you live. I don't paint my house very often. Normally I do it every three or four years.