Which slope percentage is referred to as "rolling" and may require split-level housing?

The term "rolling" slope typically refers to a gradient that presents moderate changes in elevation. This type of slope often falls within the range of 10-15%. In landscape architecture and site planning, a rolling slope can create a more dynamic aesthetic and functional environment. It may not be steep enough to necessitate extensive erosion control measures but is also steep enough to affect how buildings are situated on the site.

The requirement for split-level housing arises from the challenges that these slopes present. These homes can allow for a more effective use of the site’s topography by conforming to the natural terrain, thereby reducing the need for significant earthwork and providing better access and views.

In contrast, slopes classified as 0-5% are generally considered flat enough that split-level designs are not required. Slopes of 5-10% might start to introduce some challenges, but they usually do not necessitate special housing designs. Slopes of 15% and above are generally steep and often require different design considerations altogether, such as terracing or specialized foundations to manage the grade effectively, rather than split-level structures.