To build a solar wall oven you need a kitchen (or other convenient room) with an unshaded south facing wall. Yes, it would be less expensive to incorporate this "feature" when building a new home. Still, for those with the ability to do so, I believe there is ample reason to consider knocking a hole in your wall and adding one to an existing home. Here is why. First let's look at the benefits of using any solar oven: 1. * It does not use up non-renewable fuel resources 2. * It does not create or cause to be created any kind of pollution. 3. * The energy it uses is FREE!