When digging strip footing on sloping ground, it is often necessary to introduce a stepped foundation (see Figure 2). This is necessary to reduce the depth of the foundation because the effort to get level ground under the foundation would increase the depth of the foundation on the high side of the ground (see Figure 1). Sloping a foundation reduces the cost of the foundation but it is necessary to know how to do this properly. The figures below show the ideal considerations in the sloping of the foundation (See Figure 3).
Figure 1; Foundation of level groundFigure 2; Foundation on stepped groundFigure 3; Ideal way of stepping foundation
Adapted from Building Construction Handbook by Roy Chudley and Roger Greeno
