Buncombe County, NC Site Plans — Site Plan Review and Steep Slope Overlays

Buncombe County, anchored by the city of Asheville, features some of the most dramatic and sought-after topography in Western North Carolina. But building in the mountains comes with unique regulatory challenges. Permitting here is divided by municipality. If you live inside Asheville, Black Mountain, or Weaverville, you must use their respective city building departments. If you live in unincorporated Buncombe County, you will deal with the county's Permits and Inspections Department via the Citizen Access Development Portal. The defining feature of Buncombe County's process is the mandatory Site Plan Review (SPR). Before you can even apply for a building permit for a new home, addition, deck, or detached garage, you must submit a detailed site plan to the Planning Department. Because the county is hyper-focused on environmental protection and landslide prevention, the site plan must explicitly calculate your disturbed area and impervious surface acreage. Most importantly, if the Buncombe County GIS flags your property as being inside a Steep Slope or Protected Ridge overlay, you are legally required to hire a licensed professional to draw your site plan.

Jump To The Permit Details That Matter

In unincorporated Buncombe County, North Carolina, a Site Plan Review (SPR) is required before you can apply for a building permit for any new residential project, including additions, decks, and accessory buildings. The site plan must show property lines, structures, setbacks, streams, and specific calculations for disturbed area and impervious surface acreage. While homeowners can prepare their own site plans for standard lots, properties located within a Steep Slope or Protected Ridge overlay legally require a site plan professionally drawn by a licensed surveyor, engineer, or architect. Applications are submitted online through the Citizen Access Development Portal, with reviews typically taking 5 business days.

Building in Buncombe County means building in the Blue Ridge Mountains. That topography makes the area beautiful, but it also makes the permitting process distinctly different from flatter counties.

Before you can pull a permit for a deck or an addition in unincorporated Buncombe County, you must clear the Planning Department's Site Plan Review (SPR). To pass, you need a site plan that proves you aren't over-clearing land or building dangerously close to a steep drop-off.

Do You Need a Site Plan for a Small Permit in Buncombe County?

Yes. A Site Plan Review (SPR) is a mandatory prerequisite for all new residential projects, including single-family dwellings, additions, decks, detached garages, and accessory buildings.

Your site plan must be highly detailed and include:

  • Property lines and the location of streams/water bodies.
  • Existing and proposed structures with their dimensions and square footage.
  • Distance to property lines (setbacks) from the furthest extending portion of the structure (including overhangs).
  • Disturbed area calculations (listed in acres).
  • Impervious surface calculations (listed in acres).
  • Retaining walls (location and height).
  • Flood zone boundaries.

If your property is a standard, relatively flat lot, you can prepare this plan yourself and submit it to the Citizen Access Development Portal. If it is on a mountain, the rules change entirely.

Who Runs Into This in Buncombe County

  • New landowners who buy a scenic mountain lot, only to discover it's in a Protected Ridge overlay, requiring them to hire a surveyor and engineer just to build a small cabin.
  • Asheville residents who try to submit plans to the county portal, unaware that the City of Asheville handles its own building permits through a separate system.
  • Homeowners adding a deck who fail to calculate their "disturbed area acreage," causing their Site Plan Review to be rejected and delaying their project by weeks.
  • DIY shed builders who assume setbacks are measured from the foundation, only to fail inspection because the roof overhang crossed the setback line.

What Needs a Site Plan in Unincorporated Buncombe County

  • Fence permit site plan — Fences may require zoning permits depending on location; a site plan proves you aren't blocking rights-of-way.
  • Shed permit site plan — Required. Detached accessory buildings require SPR. Must show footprint and distances to property lines.
  • Deck permit site plan — Required. New residential decks require SPR to verify setbacks and grading.
  • Pool permit site plan — Required. Must show pool location, equipment, barriers, setbacks, and disturbed area.
  • Garage permit site plan — Required. New detached garages require SPR and must show driveway access.
  • Addition permit site plan — Required. Must show the existing house, addition footprint, new setbacks, and updated impervious surface calculations in acres.

Why This Trips People Up in Buncombe County

Steep Slope and Protected Ridge Overlays. This is the most critical regulation in Buncombe County. Because of the risk of landslides and environmental degradation, the county aggressively regulates mountain building. If the county GIS shows your property inside a Steep Slope or Protected Ridge overlay, your site plan MUST be professionally drawn. You cannot submit a homeowner sketch, no matter how accurate it is.

Disturbed Area Calculations. It is not enough to just draw the house. Your site plan must calculate exactly how much land (in acres) you are going to disturb during construction, including grading, staging areas, and material storage.

Overhang Setbacks. Buncombe County measures setbacks from the furthest extending portion of the structure. This includes patio walls, decks, and roof overhangs. If you measure your setback from the foundation wall and have a 2-foot roof overhang, you will violate the setback and fail final inspection.

The Municipal Divide. Buncombe County handles permits for unincorporated areas. If your property is inside the city limits of Asheville, Black Mountain, Weaverville, Woodfin, or Biltmore Forest, you must use their specific city development departments.

Zoning and Setbacks in Unincorporated Buncombe County

Setbacks vary by zoning district and utility access (water/sewer).

Typical Residential Setbacks:

  • Front yard: 10–20 feet
  • Side yard: 7–10 feet
  • Rear yard: 15–20 feet

Special Setback Rules:

  • Blue Ridge Parkway: Accessory buildings adjacent to the Parkway require a massive 30-foot setback.
  • Corner lots: Must maintain the required front setback from each road right-of-way.
  • Variances: Buncombe County rarely grants variances for setbacks unless the owner can prove an extreme, undue burden. If you don't meet setbacks, you must cease work immediately.

How the Tool Handles This — 5 Steps

If you are not in a Steep Slope overlay, SitePlans.ai loads Buncombe County parcel data so you can generate the detailed SPR site plan yourself:

  1. Enter your address — Lot lines load from county GIS records.
  2. Place your project — Add your deck, shed, or addition to the lot.
  3. Calculate Acreage — Use the tool's area measurement features to calculate your disturbed area and impervious surfaces, converting square footage into the required acreage.
  4. Label the setbacks — Drop distance lines from the edge of the roof overhang to the property lines.
  5. Export a clean PDF — Download a professional plan ready for upload to the Citizen Access Development Portal.

Where This Tool Fits — and Where It Doesn't

Situation Best path
Shed, deck, or addition on a standard lot SitePlans.ai for the required homeowner SPR site plan
Property in a Steep Slope or Protected Ridge overlay Licensed Surveyor/Engineer legally required
Project inside Asheville city limits SitePlans.ai for layout; verify city-specific requirements via Accela
Property with unclear boundaries Licensed Land Surveyor required
Substantial grading or retaining walls Licensed Civil Engineer required

What This Doesn't Replace

Our Site Plan creator webtool helps create preliminary, conceptual site plans for standard residential lots where Buncombe County allows homeowner-prepared drawings. It is not a licensed land survey or sealed engineering drawing. If your property falls within a Steep Slope or Protected Ridge overlay, you legally must hire a licensed professional to draw your site plan. You cannot use our software to bypass this environmental requirement.

Comparison: Your Options for a Buncombe County Site Plan

Method Cost Time Stamp Notes
Hand sketch Free 1–2 hrs Difficult to accurately calculate acreage for disturbed areas
SitePlans.ai Free first plan Minutes Calculates areas and generates a clean PDF for the Citizen Access portal
CAD drafter $300–$800+ 1–2 weeks Sometimes Overkill for a deck on a flat lot
Licensed surveyor/engineer $1,000–$3,000+ 3–6 weeks Mandatory for Steep Slope and Protected Ridge overlays
SitePlans.us (done-for-you) Custom 1–3 days Best if your first SPR attempt was rejected by the Planning Dept

Common Mistakes That Delay Buncombe County Permits

  • Skipping the SPR — Trying to apply for a building permit without first getting Site Plan Review approval from the Planning Department.
  • Ignoring the overlays — Uploading a self-drawn site plan for a property on a steep slope, resulting in an automatic rejection and demand for a professional seal.
  • Measuring from the foundation — Failing to account for roof overhangs when calculating setback distances.
  • Missing acreage math — Supplying disturbed area calculations in square feet instead of the required acreage.
  • Applying in the wrong portal — Using the county Citizen Access portal when the property is inside Asheville city limits.

Support and Local Resources

Nearby Counties

Frequently Asked Questions

1. Does Buncombe County allow homeowners to draw their own site plans?

Yes, but only if the property is not located in a Steep Slope or Protected Ridge overlay. If you are on a standard lot, you can draw your own plan for the Site Plan Review, provided it shows all required setbacks, disturbed areas, and impervious surfaces.

2. What is a Steep Slope overlay?

It is a zoning designation for mountainous areas prone to erosion and landslides. If your property is in this overlay (which you can check on the county GIS), your site plan must be professionally drawn by a licensed surveyor, engineer, or architect.

3. What is the Site Plan Review (SPR)?

SPR is a mandatory prerequisite step in Buncombe County. Before you can apply for a building permit, the Planning Department must review your site plan to ensure zoning, setback, and environmental compliance. Reviews typically take 5 business days.

4. How are setbacks measured in Buncombe County?

Setbacks are measured from the property line (or right-of-way) to the furthest extending portion of the structure. This means you must measure to the edge of the roof overhang, deck, or patio wall, not just the foundation.

5. How do I know if I'm in Asheville or unincorporated Buncombe County?

Use the Buncombe County GIS Parcel Viewer. It will display your jurisdiction. If you are inside Asheville city limits, you must submit your permits through the City of Asheville's Development Services department, not the county.

6. Can I use SitePlans.ai for a Buncombe County permit?

Yes. For properties outside the Steep Slope and Protected Ridge overlays, SitePlans.ai is an excellent tool to calculate your disturbed area acreage, verify overhang setbacks, and generate the PDF required for the Citizen Access Development Portal.

Start Your Buncombe County Site Plan

Check the Buncombe County GIS first to ensure you are not in a Steep Slope overlay. If you're on a standard lot, enter your address below to pull your property lines, calculate your disturbed area acreage, verify your overhang setbacks, and download the clean PDF you need for your SPR.

Build My Buncombe County Site Plan →

Got a correction notice from the Planning Department? Send the comments to SitePlans.us and we'll draft the revision for you.

Build My Buncombe County Site Plan

Get a Expert-Drafted site Plan