Standard Footing Design: A footing is required for piers and foundation walls. As a rule of thumb, for residential buildings, the footing is twice the width of the wall that it supports. This same design is used when the footing supports a pier or a concrete wall. As a result, the footing distributes the weight or load of the wall onto a large surface area of undisturbed earth. Because the footing is wider than the wall or pier resting on top of it, the footing also prevents the pier or foundation from lifting out of the earth.