Property development is, at its core, a local endeavor. Each municipality has its own rules and regulations for many aspects of residential and commercial development. In the mountains, one regulation that’s constantly at the forefront of all development conversations is slope ordinances.
Today, we’ve prepared a short primer about slope ordinances, including what they are, how they’re determined, and how they’re managed in Asheville and Buncombe County, NC.
What is a Slope Ordinance, Broadly Speaking?
A slope ordinance, also known as a steep-slope ordinance, is a zoning regulation designed to limit disturbance of or development on steep slopes. The purpose of the limitation is to prevent erosion, reduce the risk of dangerous landslides, and preserve scenic hillsides.
Steep-slope ordinances in the United States trace back to Los Angeles in the early 1950s. Since then, some sort of slope ordinances have been adopted by municipalities in many states across the country. Ordinances regulate many aspects of mountaintop construction, including the density of homes at high elevation, the maximum impervious surfaces allowed, and if and where trees can be cut down.
How are Steep Slopes Determined?
Slopes are simply measured as rise over run. For instance, a stretch of land 100 feet long that rises three feet in elevation has a slope of 3/100, or 3%.
Defining what constitutes “steep” for the purposes of slope regulation is at the reasonable discretion of each municipality. Generally, because slopes of 15–25% pose significant limitations to development, 15% is used as a minimum starting point for regulation. Some municipalities have different regulations for residential versus non-residential properties. Others, particularly those in hilly locations, regulate development based instead upon specific steeply sloping soil types.
What are the Slope Ordinances in Asheville and Buncombe County?
The City of Asheville and Buncombe County have slightly different regulations for building on slopes. The Buncombe County Planning Department uses a Steep Slope Overlay to “limit the intensity of development in steep areas, preserve viewsheds, and protect natural resources on land higher than 2,500 feet above sea level with a natural slope of 35% or more.” That is not to say that homes cannot be built on slopes at elevation. However, homes that are built are limited by the amount of land that can be disturbed, screening requirements, and the requirement to hire a geotechnical engineer.
Asheville, in contrast, has somewhat stricter regulations. According to the city’s “Steep Slope and Ridgetop Development Ordinance”, Asheville defines steep slopes as “those areas at or above 2,220 feet in elevation above mean sea level and having an existing grade of 15% or more.” The city has further separated elevations into two zones for the purpose of applying specific development standards. Zone A covers areas 2,220–2,349 feet in elevation, while Zone B addresses areas at or above 2,350 feet. “All areas having an existing grade of 36% or more, regardless of elevation, or are located in areas designated as High Hazard or Moderate Hazard,” are subject to additional standards.
The City of Asheville says their regulations serve several purposes. Appropriate use of hillsides maintains slope stability and controls erosion and stormwater runoff. In addition, since the mountains and hillsides of Asheville are visible from many places in the city, ridgetop regulations add to the quality of life for residents by retaining the natural beauty we love.
Learn More from the Pros at NAI Beverly-Hanks
At NAI Beverly-Hanks, we have a global reach, but we’re rooted in the local community. It’s our job to facilitate your commercial real estate goals. If you’d like more information about slope ordinances in municipalities across the Asheville MSA, we’re happy to help.