The first place to check to see if a lot is subject to Steep Slope Regulations is the Buncombe County GIS map or the MapWNC Slope Tool.
The county GIS website will show if your lot lies in the “Steep Slope Zoning Overlay,” but only if the lot is in the county and not within a township or city such as Asheville, Black Mountain, Weaverville, etc. So, if the lot is subject to oversight by one of these towns, it’s imperative to check with the local municipality to understand the specific requirements.