I love going to conferences. Since I changed my career in 2004, I've gone to building science, green building, and home performance conferences nearly every year. (I think I missed 2006, but I had a lot going on then.) Last year I went to eleven of them, but then I'm a bit unusual.
You certainly don't have to go to that many, but if you're a home builder, home performance contractor, or home energy pro, I do recommend going to one conference a year so you can keep up with the latest trends, talk to your peers, and maybe add some arrows to your quiver.