What kind of site requires a higher foundation elevation?

The correct choice indicates that a graded site requires a higher foundation elevation. A graded site has been leveled or modified to prepare it for construction, typically to ensure proper drainage and stability. Depending on the specific grading work done, these sites may be elevated above surrounding areas to manage rainwater runoff effectively and prevent flooding or water accumulation.

In contrast, flat sites generally don’t require significant elevation changes since they are already level. Hilltop sites, while elevated, typically have a natural height advantage due to the topography and may not necessitate additional elevation compared to what exists. Wetland sites present challenges related to saturation and may need specialized construction methods, but they are typically considered sensitive areas where regulating bodies would demand careful planning and potentially elevate structures to avoid moisture issues. However, grading in these cases might not be the primary factor influencing the elevation compared to engineered designs on graded sites.