My Father did exactly what you are talking about 50 years ago. The soil was heavy clay, and it was dug by hand. The house was cribbed up so footings, walls, etc could be poured. When done, one would never know that it wasn't built that way from day one. Other considerations are water table depth, and payback in todays economy. Step one would be to have a structural engineer look over the situation, and then a contractor that had experience in this type of thing should be contacted. Yours being a brick structure may present its own problems.