Furniture is by nature a very practical thing. We may want style in our furniture, but you can't call it furniture unless it's useful. Preferably VERY useful. Sometimes, with the passage of time, a piece loses its intended purpose and needs a new one. The basic idea of retrofitting is to make a treasured but non-functional piece into something lovely AND functional. In my book this means that the general lines and exterior look of the piece remain intact, but things get changed and rebuilt under the hood.