Q: If I transplant an Alberta that has been growing next to my garage will the back side turn green again and fill out.
They grow extremely slowly and, like other spruces (and pines), their growth is restricted to the ends of the branches. So, unfortunately, once you have a bare spot on a dwarf Alberta, it's likely to be there for a long long time.
This is not to say that you shouldn't give it a try.
It sounds like it was planted too close to the garage, so if you move it it'll at least have a chance to produce some growth from the sides that may eventually help to fill in the bare spot.
If it's the whole back side, though, this may never happen, and you're pretty much stuck with a one-sided spruce.