I've already replaced this superfluous garage door once. It's an easy pass from the garage to the backyard patio, but I really don't use it. This morning I unscrewed the doorsweep to find that the bottom two inches of the door are rotten. Would it be more cost effective to frame in the door space and place siding over the exterior like the rest of the garage or replace the door?

Many thanks for somebody's time-tested experience!