Thinking about adding an accessory dwelling unit to your Monroe property? A smart plan starts with the legal basics. In Monroe, zoning decides where an ADU can go, state building codes guide safety and construction, and county rules can affect septic, taxes, and more. This guide walks you through what to check before you draw plans or hire a contractor, with direct links to official resources.
ADU basics: what to expect
Building a compliant ADU is part land use, part building code, and part logistics. Here is what that means for you:
- Local zoning rules determine if your lot allows an ADU, how big it can be, where it can sit, and how many parking spaces you need. Monroe’s Unified Development Ordinance, or UDO, is the main rulebook for those standards and the permitting process in the City code library.
- You will need permits and inspections under the North Carolina State Building Codes, which the City’s Building Standards team enforces on the City site.
- If your home is on septic, Union County Environmental Health must confirm the system can handle the added bedrooms and design flow under state wastewater rules.
- Private covenants or HOA rules can be stricter than city rules, and the City does not enforce private covenants. Always check your deed and HOA before you start per the UDO overview.
The goal is to confirm eligibility first. A 20‑minute call with the City’s Permit Center can save you weeks later Permit Center.
ADU types and definitions
Local definitions control how your project is classified and reviewed. Monroe’s code references accessory living quarters and accessory apartments as uses that are secondary to a primary residence see code definitions and examples.
Detached, attached, internal ADUs
- Detached: A small backyard cottage or garage apartment in a separate building, typically located in the side or rear yard and subordinate to the main house UDO concepts.
- Attached: A unit added to the main structure, such as above a garage or as a side addition, with required fire and sound separation handled by building code building standards.
- Internal: A converted basement, attic, or portion of the existing house with its own kitchen, bath, and sleeping area.
Primary vs. accessory use
An ADU is secondary to the primary dwelling. It cannot function as a separate principal use unless the zoning district specifically allows that configuration. Placement, size, height, and design often must remain clearly subordinate to the main home UDO concepts.
Owner-occupancy and limits
Many cities limit ADUs to lots with one principal home, restrict separate sale of the ADU, and may require owner occupancy in either the main home or the accessory unit. Monroe’s UDO historically limits accessory apartments by size and occupancy. One definition example limits an accessory apartment to the smaller of a percentage of the main home or a set square footage (the code shows an example of 25 percent of gross floor area or 750 square feet). Because numeric standards can appear in multiple sections, confirm the current limits for your zoning district with the City before you plan your design see UDO definitions.
Confirm zoning and lot eligibility
Before you hire a designer, make sure your lot and zoning support what you want to build.
Find your zoning district
- Contact the City’s Permit Center to look up your parcel’s zoning and any overlays and to confirm whether an accessory apartment or similar use is allowed in that district Permit Center.
- Review Monroe’s UDO for use permissions, accessory use standards, and the zoning permit process UDO portal and the Zoning Permit section Section 3.4.20.
Lot size and coverage
Feasibility depends on lot area and how much you can cover with buildings. The UDO sets maximum lot coverage and floor area limits by district. If the accessory unit counts toward coverage, a large garage or pool might limit what still fits. Ask Planning to identify the applicable dimensional table for your district UDO portal.
Setbacks, height, placement
Accessory buildings usually belong in the side or rear yard and must meet setback and height limits, often lower than the main house. Corner lots and alleys can change where doors and driveways go. Confirm setbacks and height for accessory structures in your zone and whether design rules apply in historic areas UDO concepts and Historic District info.
Parking and access
Parking requirements come from the UDO’s parking table. For example, single‑family detached housing requires 2 spaces per dwelling unit. If the accessory apartment is treated as an additional dwelling unit, you may need to provide an extra space on site. Verify how Monroe applies Table 8.4.1 to accessory apartments and how tandem spaces or driveway expansions are counted parking table.
Map your approvals and permits
A clear submittal roadmap helps you avoid delays.
Pre-application with planning
- Call Planning through the Permit Center to confirm use, size caps, parking, setbacks, and any owner‑occupancy rules for your lot. Bring a survey or sketch with dimensions, driveway location, and utility notes Permit Center.
- If you are on septic, contact Union County Environmental Health early to screen capacity and fees county Environmental Health.
Permit submittals and plans
- Zoning permit: Many ADUs require a zoning permit that checks use and site standards. See the UDO’s Zoning Permit section for triggers and submittal requirements Section 3.4.20.
- Building permits: The City enforces the North Carolina State Building Codes. Plan on building, electrical, mechanical, and plumbing permits, with City plan review and staged inspections Building Standards.
- Septic permits: If not on public sewer, Union County Environmental Health issues septic evaluations and improvement permits. They also publish a fee schedule for site evaluations and construction authorizations fee schedule.
- Contractor licensing: In North Carolina, a state general contractor license is required for projects with a contract value of 40,000 dollars or more. Verify the threshold and your contractor’s license before you sign NC statute.
- Fees and timelines: The City maintains fee updates and uses an online CityView portal. Ask the Permit Center for current plan review time and estimated fees for your scope City news on fee schedule.
Typical plan package
- Site plan with setbacks, parking, and utility connections
- Architectural plans with sections and elevations
- Structural notes and code compliance details
- Energy code details and mechanical layout
- Contractor license and contact details
Inspections and certificate
Expect foundation, framing, electrical, plumbing, HVAC, and final inspections. You will need a final approval or Certificate of Occupancy before you use the ADU as a dwelling Building Standards.
HOAs and overlays
Private covenants and HOA rules can prohibit rental units, limit detached buildings, or control exterior design. The City does not enforce private covenants, so you must review your deed restrictions. Projects in Monroe’s Historic District may need a Certificate of Appropriateness for exterior changes Historic District and UDO portal.
Design and construction basics
Fire, foundation, separation
- Attached or above‑garage units can require rated wall and floor assemblies, protected openings, and proper stair enclosures. Detached units must meet foundation and structural standards. The City’s Building Standards team reviews plans under the NC Building Codes Building Standards.
- Provide egress windows in sleeping rooms, interconnected smoke alarms, and CO alarms as required by code Building Standards.
Water, sewer, power meters
- Public utilities: Coordinate taps and meters with the City. Separate electric or water meters may be possible, but the setup and billing rules vary by utility and project type. Ask City Energy Services and Utility Billing how they handle accessory units Energy Services.
- Septic: Do not assume your system can handle an ADU. State rules define ADUs and design flows by bedroom count. The county will determine capacity and any required upgrades before you can connect a new unit state wastewater rules and county Environmental Health.
Addressing and emergency access
Clear addressing, visible entry paths, and safe access for fire and EMS help both emergency services and deliveries. Ask the City whether a secondary address or unit identifier will be assigned during permits Permit Center.
Impact and tap fees
Utility tap fees and other charges may apply. Get estimates at concept stage so you can budget accurately and avoid surprises at permit issuance Permit Center and City fee update.
Renting the ADU legally
Long-term rental rules
Monroe’s UDO can set limits on occupancy, parking, and whether the ADU can be rented at all. Some accessory‑apartment rules restrict separate sale or set owner‑occupancy requirements. Verify your specific parcel’s rules with Planning and review the UDO text that applies to accessory apartments UDO concepts and code portal.
Short-term rental limits
Short stays often follow different rules than long‑term leases. If you plan to use an ADU as a short‑term rental, ask the City about any local requirements or limits. Private HOAs may also restrict short stays even if the City allows them UDO portal.
Fair housing and taxes
If you rent your ADU, follow fair housing laws and keep clean lease files. Construction that adds value will be assessed by the county, which can change your tax bill. Check Union County’s appraisal and valuation resources to understand how and when new improvements are picked up County appraisal.
Records and compliance
Save copies of permits, approved plans, inspections, and any zoning approvals. If you ignore rules or skip permits, the City can issue stop‑work orders or require you to remove or convert the unit. Code enforcement details are on the City site Code Enforcement.
Next steps to move your ADU forward
Use this quick checklist to move from idea to action:
- Confirm eligibility
- Call the City’s Permit Center with your address or parcel number. Ask if your zoning allows an accessory apartment, which UDO section applies, and what numeric limits control size, bedrooms, and parking Permit Center and UDO portal.
- Verify sewer or septic
- If on septic, schedule a site evaluation with Union County Environmental Health and review fees and timelines county Environmental Health and fee schedule.
- Plan permits and team
- If your project budget is 40,000 dollars or more, hire a licensed NC general contractor. Confirm the licensing threshold and verify credentials NC statute.
- Ask the City about expected plan review timelines and fees so you can schedule design and financing City fee update and Building Standards.
- Check HOA and historic rules
- Read your covenants. If you are in the Historic District, review the design standards and Certificate of Appropriateness steps before exterior work begins Historic District.
- Submit complete plans
- Include a clear site plan, architectural drawings, utility details, and contractor information to reduce rounds of comments Zoning Permit.
Ready to explore how an ADU could add living space or rental income to your property? For a bilingual, local perspective on zoning fit, resale impact, and rental strategy, connect with Maldonado Group International Realty. We can review your parcel, coordinate with the City, and help you plan next steps.
FAQs
Is an ADU allowed on my lot in Monroe?
- Start with your zoning district. Call the City’s Permit Center to confirm if an accessory apartment is permitted and which UDO section applies to your parcel Permit Center and UDO.
How big can my ADU be?
- Monroe’s UDO ties size to the main house and zoning standards. One code definition example limits an accessory apartment to the lesser of a percentage of the main home or a fixed square footage. Confirm your exact numeric limits with Planning before you design UDO definitions.
Do I need extra parking for an ADU?
- Likely. The UDO’s parking table sets spaces per dwelling unit. If the ADU counts as another unit, you may need an additional on‑site space. Verify with the City how Table 8.4.1 applies to your plan parking table.
What permits are required?
- Expect a zoning permit for use and site compliance and building permits for construction under NC codes. If on septic, you will also need county approvals before building Zoning Permit section, Building Standards, and county Environmental Health.
What if I am on a septic system?
- The county must confirm capacity and may require upgrades based on bedrooms and design flow. Do this first to avoid redesign later state wastewater rules and county Environmental Health.
Can I rent the ADU short term?
- Short‑term rentals can be restricted by local rules and HOAs. Ask the City and check your covenants before listing the unit UDO portal.
Will my taxes go up?
- Likely. An ADU is new improvement that the county will assess. Review how Union County handles new construction and valuation timing County appraisal.
What happens if I build or rent without permits?
- The City can issue stop‑work orders, fines, or require removal or conversion. Keep records of approvals and inspections to stay compliant Code Enforcement.
