Thursday, March 2, 2023 / by Amy Brown
Building in WNC series, Part 2: screening plan, geotechnical, and Ridgeline ordinance
Three additional requirements are mandatory by the county for new construction in WNC; a screening plan, a geotechnical engineer's report, and compliance with the Ridgeline ordinance.
Screening Plan
A screening plan is a vegetation requirement in order to cover up large, unsightly foundations.
Before screening After screening
A screening plan is required when the slope at the downhill facing side of the building drops 25 vertical feet or more in elevation within 100 horizontal feet of the structure. You are also required to either keep an existing tree or plant a tree at least 6” in height for every 200 square feet of planar surface. All trees must be within 50’ of the downhill side of the structure, be native species, and no one species can comprise more than 50% of the plantings.
Source: Buncombe county planning and development
Geotechnical Engineer
A geotechnical engineer’s report is a requirement when building on any lot under the county’s steep slope ordinance and is completed in two stages. This report determines whether building is feasible based upon grade, erosion likelihood, natural runoff lines, soil type and compaction, and previous landslide disturbance. It is highly recommended that you complete the first stage during the due diligence period, prior to purchase, so that it can be determined whether building is even feasible at all and so that you can rescind the contract with minimal money loss and no repercussions should this not be the ideal parcel for your design.
Ridgeline Ordinance
The protected ridge overlay includes additional requirements for minimum lot size, density, height, and building lot width that apply when a structure is within 500 horizontal feet of a designated protected ridge. Structures located within 50 vertical feet of a designated protected ridge have a maximum average height from ground level to roof peak of 25’. Structures located more than 50 vertical feet from a protected ridge and structures in the Steep Slope overlay have a maximum average height of 35’.
How to know if your selected parcel is governed by the steep slope ordinance
County steep slope ordinance locators can be found on the Buncombe County Geographical Information System. Your real estate agent should be able to readily provide this to you. However, there are additional steep slope requirements depending upon whether the lot that you choose is inside of a municipality. For example, Asheville’s steep slope ordinance is more strict and encompasses all parcels above 2220’ in elevation and having a grade of 15% or more.
In summary, topography matters! This can be an enormous barrier to new construction, design, and cost so make sure to do your research when considering a particular land parcel.