Durham County, NC Site Plans — Plot Plans and the Dplans Portal

Durham County is one of North Carolina's fastest-growing regions, driven by the tech and research boom in the City of Durham. Fortunately for homeowners and contractors, Durham operates a merged city-county government. The Durham City-County Inspections Department handles building permits and zoning reviews under a single Unified Development Ordinance (UDO). You won't have to guess whether you need to visit a city office or a county office. However, the unified system is highly rigorous regarding environmental protections. For any project that changes the footprint of your property, you must submit a plot plan (site plan). This plan must not only show the exact dimensions and setbacks of your new deck or shed, but it must also explicitly list your allowable and proposed impervious surface calculations. Furthermore, Durham has strict floodplain regulations; if you are near a Special Flood Hazard Area, a homeowner sketch won't cut it—you will need a sealed drawing from a licensed professional. For standard residential projects outside the floodplain, Durham accepts homeowner-drawn plans, provided they meet scale and clarity requirements for the Dplans digital portal.

Jump To The Permit Details That Matter

In Durham County, North Carolina, building permits are managed by the unified Durham City-County Inspections Department. A scaled and fully dimensioned plot plan is required for any project that changes the property's footprint, including additions, decks, pools, and sheds. The plot plan must show property lines, existing structures, the proposed structure, exact setback distances, and critically, a calculation of the lot's impervious surface area. Homeowners may prepare their own plot plans for most standard residential projects, which must be submitted digitally through the Dplans portal. However, if the property is located in a Special Flood Hazard Area, a certified drawing sealed by a licensed NC Professional Engineer or Surveyor is mandatory

Durham's merged city-county government makes figuring out where to apply for a permit incredibly easy. But figuring out what to submit requires close attention to the Unified Development Ordinance (UDO).

The Durham City-County Inspections Department requires a plot plan for virtually any exterior improvement. Because Durham is highly focused on watershed protection and flood prevention, a simple sketch of a shed won't get approved. You must provide hard math regarding your lot coverage and prove you are clear of environmental hazards.

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

Yes. If your project consists of a change in the footprint of your property, you must submit a scaled and fully dimensioned plot plan.

Durham accepts plot plans prepared by the property owner, provided they meet the official requirements. Your plan must include:

  • Property lines with actual measurements on each line.
  • Existing structures and proposed structures, with clear dimensions and the exact distance to property lines (setbacks).
  • Scale (must be drawn to an acceptable engineering scale) and a North arrow.
  • Impervious surface math: You must list both the allowable and proposed impervious surface in square feet.
  • Easements, streams, and restrictions.
  • Streets and utilities located on or adjacent to the property.

Crucial Note: If your plan contains "Draft" or "Not for Construction" watermarks, it will be rejected by the Inspections Department.

Who Runs Into This in Durham County

  • New residents who pour a large concrete patio, completely unaware that Durham caps impervious surfaces to protect local watersheds, resulting in a costly zoning violation.
  • Homeowners near creeks who try to submit a self-drawn plot plan for a shed, only to find out they are in a Special Flood Hazard Area that legally requires a sealed engineering survey.
  • DIYers who sketch a deck on a napkin and try to upload a cell phone photo to the strict Dplans digital portal.
  • Shed buyers who assume a 10x14 shed is small enough to avoid a permit, ignoring North Carolina's strict 12-foot dimension rule.

What Needs a Plot Plan in Durham County

  • Fence permit site plan — Required for any activity adding a structure or improvement to ensure you aren't blocking easements.
  • Shed permit site plan — Required. Sheds over 144 sq ft or with any dimension exceeding 12 feet require full building permits. Sheds on skids require tie-downs.
  • Deck permit site plan — Required. Must show footprint, height above grade, and setbacks.
  • Patio permit site plan — Required to calculate the new impervious surface total.
  • Pool permit site plan — Required. Must show pool location, equipment, barriers, and flood zone notation.
  • Garage permit site plan — Required for all accessory structures.
  • Addition permit site plan — Required. Must show the existing house, new footprint, updated setbacks, and new impervious surface calculations.
  • ADU ( (Accessory Dwelling Unit) — ADUs are permitted by right in Durham on lots with 1 or 2 primary units. A plot plan is required showing the footprint, setbacks, and parking.

Why This Trips People Up in Durham County

Impervious Surface Calculations. This is the #1 reason homeowner plot plans are rejected in Durham. You cannot just draw the structure. You must calculate the square footage of everything on your lot that doesn't absorb water (roofs, concrete, asphalt) and compare it to the allowable cap for your specific zoning district.

The Floodplain Requirement. Durham has strict rules regarding the Special Flood Hazard Area (SFHA). If your property touches one of these zones, you cannot draw your own plot plan. A Floodplain Development Permit is required, and your plan must be a certified drawing sealed by a licensed NC Professional Engineer or Surveyor, establishing Base Flood Elevations and a 2-foot freeboard.

The Dplans Portal. Durham City-County uses the Dplans system for digital submissions. Your plot plan must be a clean, legible PDF. All document security must be removed before upload, and the scope of work on the plan must perfectly match the permit application description.

The 12-Foot Rule. Durham enforces the state building code: if an accessory structure has any dimension exceeding 12 feet, it requires a building permit.

Zoning and Setbacks in Durham County

Setbacks are governed by the Durham UDO and are measured perpendicularly from the property line to the closest part of the building line.

While setbacks vary heavily by your specific zoning district, Durham also enforces unique grading and tree requirements:

  • Grading Setback: A minimum 5-foot undisturbed grading setback must be maintained from all exterior boundaries.
  • Trees: All trees required by the UDO must be depicted on your plot plan, including location, caliper, and species.
  • Buffers: Buffer authorization from the NC Dept. of Water Resources may be required before approval.

How the Tool Handles This — 5 Steps

SitePlans.ai loads Durham County parcel data so you can generate the exact type of PDF the Dplans portal requires, complete with the math the county demands:

  1. Enter your address — Lot lines load from county GIS records.
  2. Place your project — Add your deck, shed, or ADU to the lot.
  3. Auto Calculate Impervious Surface — Use the tool's area measurement features to calculate your existing roof and driveway, plus the new structure, to list on your plan.
  4. Label the setbacks — Drop distance lines from your proposed project to the side and rear property lines.
  5. Export a clean PDF — Download a professional, unencrypted PDF ready for the Dplans portal.

Where This Tool Fits — and Where It Doesn't

Situation Best path
Standard shed, deck, or patio SitePlans.ai for the required homeowner-drawn plot plan
Unincorporated county or city limits SitePlans.ai (the merged agency accepts the same plans)
Property in a Flood Hazard Area Licensed PE/Surveyor required
Property with unclear boundaries Licensed Land Surveyor required
Substantial commercial grading Licensed Civil Engineer required

What This Doesn't Replace

SitePlans.AI helps create preliminary, conceptual plot plans for residential projects where the Durham City-County Inspections Department allows homeowner-prepared drawings. It is not a licensed land survey or sealed engineering drawing. If your property is in a floodplain, you legally must hire a licensed North Carolina Professional Engineer or Professional Land Surveyor to prepare your Floodplain Permit Application.

Comparison: Your Options for a Durham County Site Plan

Method Cost Time Stamp Notes
Hand sketch Free 1–2 hrs Allowed, but calculating impervious surfaces and formatting for Dplans is hard
SitePlans.ai Free first plan Minutes Generates the clean PDF and area measurements needed for Dplans
CAD drafter $300–$800+ 1–2 weeks Sometimes Overkill for most residential footprint changes
Licensed surveyor / PE $500–$2,000+ 2–4 weeks Mandatory for any work inside a Special Flood Hazard Area
SitePlans.us (done-for-you) Custom 1–3 days Best if your first attempt was rejected by the county for missing math

Common Mistakes That Delay Durham County Permits

  • Forgetting the impervious surface math — Submitting a plan without explicitly listing the allowable vs. proposed square footage.
  • Submitting a locked PDF — Uploading a digitally signed or encrypted PDF to Dplans (which the county software cannot process).
  • Ignoring the 5-foot grading setback — Planning to grade the soil right up to the property line.
  • Missing tree data — Failing to show UDO-required trees on the plot plan.
  • Attempting DIY in the floodplain — Trying to submit a homeowner-drawn site plan for a property that touches a flood zone.

Support and Local Resources

  • Durham City-County Inspections Departmentdurhamnc.gov/406
  • Dplans Digital Portaldurhamnc.gov/467/Dplans — for all digital submissions.
  • Durham Maps (GIS)maps.durhamnc.gov — verify your parcel, zoning, and flood zones here.
  • Durham City-County Planning — 919-560-4137 (call to verify specific UDO setbacks and impervious caps).
  • FEMA Flood Mapsmsc.fema.gov

Nearby Counties

Frequently Asked Questions

1. Does Durham have separate city and county permit offices?

No. Durham operates a merged city-county government. The Durham City-County Inspections Department handles permits for both the city and the unincorporated county under a unified set of rules.

2. Does Durham allow homeowners to draw their own plot plans?

Yes, for most standard residential projects. The plan must be drawn to scale, include precise distance measurements, calculate impervious surfaces, and be submitted digitally. However, if your property is in a floodplain, you must hire a licensed professional.

3. What is the rule for sheds in Durham County?

Like the rest of NC, if any dimension of the shed exceeds 12 feet, a building permit is required. Even if a building permit isn't required (e.g., a 10x10 shed), you may still need a zoning permit and a plot plan to verify setbacks. Note that sheds on skids must have tie-downs.

4. What does "impervious surface" mean on my Durham plot plan?

Durham caps the amount of your lot that can be covered by surfaces that don't absorb rainwater (like roofs, driveways, and concrete patios). Your plot plan must calculate the exact square footage of these surfaces to prove you aren't exceeding your zoning district's limit.

5. How do I submit my plot plan?

You must submit it digitally via the Dplans portal as a clean, unencrypted PDF.

6. Can I build an ADU in Durham?

Yes. Accessory Dwelling Units are permitted by right in Durham on residential lots with one or two primary units. You do not need a special use permit, but you do need a building permit and a plot plan showing the ADU and the required parking.

7. Can I use SitePlans.ai for a Durham County permit?

Yes. For projects outside the floodplain, SitePlans.ai is an excellent tool to measure your impervious surfaces, verify your setbacks, and generate the digital PDF required by the Dplans portal.

Start Your Durham County Site Plan

Check your property on Durham Maps GIS to ensure you aren't in a flood zone. If you're in the clear, enter your address below to pull your property lines, calculate your impervious surfaces, label your setbacks, and download the clean PDF you need for the Dplans portal.

Build My Durham County Site Plan →

Got a correction notice from the Inspections Department? Send the comments to Site Plans US and we'll draft the revision for you.

Build My Durham County Site Plan

Get a Drafter-Created Site Plan