ADU Regulations in District of Columbia (DC)
District of Columbia is rated Moderate for ADU construction with an ADU-friendliness score of 70/100 (ADU-Friendly). District of Columbia has a statewide ADU law that sets baseline rules across all municipalities. Owner must reside on the property. No additional parking required for ADUs. DC allows ADUs by right on most residential lots through its zoning code (Subtitle U, Chapter 2). Both attached and detached ADUs are permitted. Owner must reside on the property. ADUs cannot exceed 900 sq ft. Short-term rental restrictions apply. DC has seen growing ADU construction since zoning reforms in 2016.
Full ADU Regulations Summary for District of Columbia
| ADUs Allowed | Yes |
| Statewide ADU Law | Yes |
| Maximum ADU Size | 900 sq ft |
| Owner Occupancy Required | Yes |
| Parking Required | No |
| Minimum Setback | 3 ft |
| Permitting Timeline | 90 days |
| Impact Fees | None |
| Long-Term Rental Allowed | Yes |
| Short-Term Rental (Airbnb) Allowed | No |
| Ease of Building | Moderate |
ADU Regulations by City in District of Columbia
ADU rules can vary by city even within the same state. While District of Columbia's statewide law sets minimum standards, some cities have additional local provisions. Below are ADU details for 1 cities in District of Columbia.
Washington
ADUs (called 'accessory apartments') allowed by right in residential zones. Must be 900 sq ft or less. Owner occupancy required. No additional parking. Building permit required.
How District of Columbia Compares to Other States
Below is a comparison of District of Columbia with five states that have similar ADU-friendliness scores. This comparison helps illustrate where District of Columbia stands nationally.
| State | Score | Statewide Law | Parking Req? | Owner Occ? | Ease |
|---|---|---|---|---|---|
| District of Columbia (DC) | 70 | Yes | No | Yes | Moderate |
| New Jersey (NJ) | 66 | Yes | No | Yes | Moderate |
| Hawaii (HI) | 75 | Yes | No | No | Moderate |
| Virginia (VA) | 75 | Yes | No | No | Moderate |
| New York (NY) | 76 | Yes | No | Yes | Easy |
| Rhode Island (RI) | 63 | Yes | No | Yes | Moderate |
Frequently Asked Questions About ADUs in District of Columbia
Can I build an ADU in District of Columbia?
Yes, ADUs are allowed in District of Columbia. District of Columbia has a statewide ADU law that requires local jurisdictions to permit ADUs on residential lots. This means your city cannot outright ban ADUs. The ease of building is rated "Moderate" with a friendliness score of 70/100.
Do I need to live on the property to have an ADU in District of Columbia?
Yes, District of Columbia generally requires owner occupancy — the property owner must live either in the main house or the ADU. This means you cannot rent out both units simultaneously.
How big can an ADU be in District of Columbia?
The state maximum ADU size in District of Columbia is 900 square feet. Local jurisdictions may set lower limits. Some cities also limit ADU size to a percentage of the primary dwelling (e.g., 50%).
Do I need extra parking for an ADU in District of Columbia?
No, District of Columbia does not require additional parking for ADUs. This is a significant advantage, as parking requirements are often the biggest barrier to ADU construction on smaller lots.
Can I rent out my ADU in District of Columbia?
Yes, long-term rentals of ADUs are allowed in District of Columbia. However, short-term rentals (like Airbnb) of ADUs are restricted in District of Columbia. You can rent your ADU for long-term tenants but not as a vacation rental.
How long does it take to get an ADU permit in District of Columbia?
The permitting timeline in District of Columbia is: 90 days. The statewide law sets maximum review periods that cities must comply with. Actual timelines can be affected by plan review backlogs, inspection scheduling, and the complexity of your project. Pre-approved ADU plans, where available, can significantly speed up the process.
Check ADU Rules for Your City
Use our ADU regulations lookup tool to find the specific rules for your city in District of Columbia, or browse all 50 states to compare ADU regulations across the country. Remember that local rules may be more specific than state-level regulations.