Ground surfaces greater than 5 percent are perceived as being more sloped and become increasingly difficult to work with as their degree of slope increases. People readily see objects or areas of the landscape located at the bottom of a slope very much like they do in an outdoor amphitheater (Figure 13—17). In either situation, extra time and money must often be spent to overcome the inherent instability of a sloped site. If not handled correctly, some walls and floor areas of the house may get wet, causing visual and structural damage. First, it is difficult to get stable footing on sloped ground. The eye is invited to move along a sloped plane rather than resting as it is able to do in a level surface. While standing on sloped ground, one foot is invariably higher than the other (Figure 13-16). They, too, must be designed to get “stable footing” by creating level terraces for their location or by special structural systems that connect them to the sloped ground. On steep sites, the orientation is very likely to be away from the site toward some distant area of the landscape. Figure 13-17
The natural orientation on sloped ground is downhill toward a lower elevation. When compared with a level or horizontal plane, a sloped plane visually implies potential movement, action, or change. Even people usually find it easier to walk down a slope than up one. However steep, all sloped sites possess a number of special circumstances
Figure 13-15
Outdoor use areas and walks should be elevated on decks above the ground to minimize soil compaction in a wooded site. The steeper the site, the more pronounced these conditions are. A person must exert continual energy to stay put in any given location because there is a constant feeling of being pulled downhill. The instability of a sloped site is also a visual one. Water, soil, stones, debris, and so forth all gravitate down
Figure 13-16
Sloped ground creates unstable footing for people and structures. This can be exciting in some cases, but disconcerting in others. As discussed in Chapter 11, it is necessary to
Figure 13-18
Some areas of a sloped site may drain toward the house, thus creating potential wet conditions and damage in the house and basement. that should be thought about in designing a single-family residential site. the slope over time. Figure 13-19
A slope analysis identifies different categories of slope steepness on a site. Unless the house is located on the crest of a hill, it is quite likely that some portion of a sloped site will drain toward the house (Figure 13—18). Figure 13-20
Outdoor use areas should be carefully matched to the different slope conditions of the site. A sloped site is one that has some portion of the ground surface located on an inclined plane. Steeply sloped sites located in areas of distinct topography are frequently valued for the views they afford. regrade the uphill area of the site to divert the surface drainage around the house.
