What is the minimum height requirement for a foundation on a level site above street elevation?

The minimum height requirement for a foundation on a level site above street elevation is indeed 12 inches plus an additional 2%. This standard is typically established to ensure proper drainage away from the foundation, which helps to prevent water from pooling around the base of the structure. Proper elevation protects the building from potential water damage and contributes to the longevity and stability of the foundation.

In many building codes and regulations, a foundation that is at least 12 inches above the street elevation serves as a benchmark to minimize risks related to flooding and erosion. The additional 2% allows for slight variations in grading that may occur during construction or in response to changes in landscape, ensuring that the foundation remains adequately elevated.

It's important to adhere to these standards, as failing to meet them can lead to serious structural issues and increased maintenance costs in the future.