Minimize Grading

As already mentioned, some site grading or earth moving is a common and necessary activity during construction in order to fit the house and other structures into the landscape, to direct site drainage, or simply for aesthetic objectives. It is undertaken by heavy equipment such as a bulldozer, Bobcat, or backhoe, although fine grading is frequently done by hand. However it is performed, grading disturbs the soil by alter­ing its natural profile and compacting it. Additionally, existing vegetation is almost al­ways removed if not disturbed, and drainage patterns are modified. Poor grading can also produce extreme cut or soil removal in some areas of a site while creating exces­sive fill or added soil in other locations. This can create severe slopes that are suscepti­ble to erosion and ruin the natural contours of the ground.

To minimize grading, the house and site structures should be located on rela­tively level ground or parallel to the contours, as portrayed in Figure 3—2. This may require the house being placed so that it is not in the middle of the site or aligned with the property lines. On steep sites, grading can be reduced by using retaining walls up­hill and/or downhill from the house, building the house into the slope with a lower walkout level, or elevating the house above the slope with post-and-beam construc­tion (Figure 3—3; also see “The Sloped Site,” Chapter 13, page 460). Before construc­tion begins, a clear edge to grading should be established both on paper and in the field with a visible barrier. Grading should be undertaken with the lightest equipment possible or even by hand when feasible to reduce soil compaction. Finally, all topsoil within the graded area should be carefully removed and stockpiled before additional grading takes place. The topsoil can later be spread back over the graded area to pro­vide a beneficial growing medium.