As a rule of thumb, any total new building footprint area of 1,000 square feet or greater will usually indicate a land disturbance of greater than 2,500 square feet.
To calculate the land disturbance area for your project, add up the following areas for your site:
- The area of any proposed building addition or stand-alone structure and any other improvement (stairs, driveway, patio, etc.) that will result in land disturbance.
- A 10-foot wide work zone around the perimeter of the proposed structure, except:
- When the distance between the property line and the proposed structure is less than 10-feet, that distance may be used.
- For construction of improvements such as paved driveways, sidewalks, and ground level decks, a minimum of a 5-foot wide work zone around the structure may be used.
- For the installation, removal or capping of underground utility lines, a minimum of a 5-foot work zone centered on the utility line.
- A 10-foot wide work zone around any portion of the existing structure that will have an additional story added.
- Areas used for stockpiling. The area for the stockpile must include the access from the improvement area to the stockpile area, as well as the entire stockpile area itself.
- Unpaved areas that will be used as access to the proposed construction work area. A minimum 10-foot wide path from the street or driveway to the work area should be included in the disturbed area calculation.
- Unpaved areas that will be used as access to the proposed construction work area, staging and storing of materials, including dumpsters, gravel, stone, masonry, lumber and construction equipment.
- Areas over which excavated soil will be spread, that are not included in any of the above areas.
ThisCalculation Example can help to better determine how to calculate the area of disturbance for your project.
If your total disturbed area is between 2,000 and 2,499 square feet, you will be required to obtain a survey of the disturbed area with survey markings on your site to ensure it’s not larger than 2,500 square feet. Prior to receiving your permit, silt fence or other E&S perimeter control approved by the County must be installed around the perimeter of your disturbed area to demarcate the area and prevent soil erosion.