From my experiences with dogs in general, one year old is still pretty young! I find that by 2 they have matured. Angel didn't chew much on furniture, etc., but my golden, on the other hand, chewed the corners of just about every piece of furniture!! Including the corners of a thousand dollar bed that was brand new!
If Angel cannot be supervised, he is in his crate! He's 2 now and doesn't chew things anymore, but the crate is for his safety more than anything. It only takes a second, and one time for them to jump off a piece of furniture and get hurt! a little paranoid, maybe, but I hate seeing them get hurt. And on an overall basis, he isn't crated much at all!!
Lots of chew toys and exercise is key. Maybe you can confine him while you shower!