Volume Three Appendix 26 Appendix 26 Recession Plane and Height Controls 1. Recession Plane – Height in Relation to Boundaries The recession plane angle of inclination from horizontal depends on the orientation of the boundary concerned – see Figures 1a and 1b. Guidelines for Use Figure 1a. Recession Plane Indicator. Figure 1b. Recession Plane Cross Section. App 26 - 1