My front porch is supported by 2.5 foot high red brick pillars on each corner (one brick wide on a side). Under the porch (including the pillars) runs a three sided red brick wall following the porch perimeter; it's 4 feet deep. Inside it is open; it has dirt at the bottom and part of the top exterior front basement wall is therefore exposed. One porch corner has some rotted porch flooring and this has caused the porch to start leaning. (1) What foundation is best for the porch? Would it have to be post or pier with a footer below that lower wall? (The house is 1920's vintage in northern Ohio; the brick pillars have stood OK for 25+ years that I know of.) (2) Would this involve filling the entire void beneath the porch?