Facade: The facade is the face or the frontal aspect of a form. The photograph of the outhouse below is taken from straight-on and is an example of facade in this regard.
Proportion: Proportion is the size of something compared with other elements or against a mental norm or standard. The proportions of the photograph below are all conforming to mental norms and standards. If the outhouse was scaled to twice its size in this picture, then the proportions would be abnormal.