ADU rules in Prince George's County
Prince George's County is close but not there. Two bills carry the ADU law: CB-074-2026, the definitions and zones, passed committee 3 to 0 on September 8, 2026, and its companion CB-092-2026, the regulations, had its hearing on October 26, 2026 and was set for second reading. On October 5, 2026 the county said it would ask the state for an extension past the October 1 deadline.
The permitting side moved first. DPIE Adoption Bulletin 2026-03, dated October 14, 2026, cites CB-74 and applies the International Residential Code to ADUs. This page tells a Bowie, Laurel, Fort Washington or Hyattsville homeowner where the rule stands, what the permits will look like, and what the published numbers say an ADU costs. We do not build. We connect you with a licensed Maryland builder who does.
CB-074-2026 and CB-092-2026, pending
Pending second reading as of October 31, 2026
CB-074-2026 (definitions and zones) passed committee 3 to 0 on September 8, 2026.
CB-092-2026 (regulations) had its hearing on October 26, 2026 and is set for second reading.
On October 5, 2026 the county said it will ask the state for a deadline extension.
DPIE Adoption Bulletin 2026-03 (October 14, 2026) cites CB-74 and applies the IRC to ADUs, with interconnected alarms and the IRC rules.
Read on the county council bill pages and the DPIE building codes bulletins page, October 31, 2026. The bulletin PDF itself is behind a bot wall from our end; we quote what the bulletins page says about it.
What Prince George's allows
- No county ADU definition in force yet; CB-074-2026 carries the definitions and the zones where an ADU is allowed.
- CB-092-2026 carries the regulations (size, occupancy, parking). Read the enrolled bill, not the draft, before you design.
- The state law (Chapter 196 of 2025) sets 75 percent of the main house as the ceiling a county cannot go below, no impact fee under 750 square feet, and no parking mandate within three quarters of a mile of transit.
- DPIE Adoption Bulletin 2026-03 applies the International Residential Code to ADUs, so the building side is settled even while the zoning bills wait.
Detached, attached or basement
Detached
Not permitted under a county ADU rule until the bills pass. When they do, a detached unit is a new one family dwelling under the state building code and gets a full NFPA 13D sprinkler system; the DPIE bulletin applies the IRC to it.
Attached
An addition with its own kitchen and door. Under the bulletin, interconnected smoke alarms and the IRC rules apply; sprinklers follow the house. Inside an unsprinklered house the state code does not force them.
Basement
A conversion inside the house. Ceiling height, a second way out and moisture decide it. No sprinklers unless the house already has them.
Permits in Prince George's, in the order you meet them
- 1
Zoning
No ADU zoning path until CB-074-2026 and CB-092-2026 pass. Watch the council calendar for second reading and the enrolled text.
- 2
Building permit
A residential building permit through DPIE, filed in the Momentum online system (required for every building, fire system and trade permit since July 15, 2024). A detached unit files as new residential construction; a conversion or addition files as an addition or alteration.
- 3
Fire protection permit
A detached ADU gets a 13D sprinkler design and a DPIE fire system permit. An attached or basement unit in an unsprinklered house normally does not.
- 4
Health (well and septic lots)
Well and septic lots in the south county (Brandywine, Accokeek, Croom) need the Health Department to confirm the well and septic carry a second kitchen and bath before the permit issues. WSSC lots skip this step.
- 5
Utilities
WSSC water and sewer: a tap off the house line or a new service, sized for sprinkler flow on a detached unit. Electric: a sub panel or a second Pepco meter, your call with the builder.
The whole list, statewide, in the order a homeowner meets it:
ADU permit checklistWhat an ADU costs in Prince George's County
No builder and no county page publishes a Prince George's County specific ADU price. The ranges below are Maryland wide, from one named builder page. Ask the builder for a Prince George's number off your lot and plans once the bills pass.
| Type | Published range |
|---|---|
| Detached new build | $120,000 to $300,000 and up |
| Attached addition | $100,000 to $250,000 |
| Basement conversion | $80,000 to $200,000 |
| Garage conversion | $75,000 to $150,000 |
Source for the table:
Clarksville Construction Services, "How much does it cost to build an ADU in Maryland"County fees
County permit fees on top of construction, from the DPIE Fee Schedule effective March 2, 2025 (CR-087-2024). A new schedule, CB-067-2026, was proposed in 2026:
- Residential additions: a $66 administrative fee plus $1.17 per square foot of new area.
- Home Builder Guarantee Fund: $50 per new dwelling unit, no technology fee on it.
- A 10 percent technology fee on every DPIE and Health permitting fee.
- Modification or revision of a residential building permit after issuance: $132 minimum.
Source for the fees:
Prince George's County DPIE Fee Schedule (PDF)Sprinkler cost
A detached unit adds the NFPA 13D sprinkler system. On public water that runs about $1.35 to $1.60 per sprinklered square foot (Maryland Fire Sprinklers cost guide, marylandfiresprinklers.com/cost/). A well lot adds a storage tank and pump, priced on the same guide.
Statewide ranges and how the types compare:
ADU cost in MarylandThe sprinkler question, answered once
When Prince George's County allows a detached ADU, that unit is a new one family dwelling and gets an NFPA 13D sprinkler system the county cannot waive (Public Safety Article 12-504). An attached or basement unit inside an unsprinklered house does not trigger one. Our sister company, Maryland Fire Sprinklers, designs, permits and installs them.
A licensed builder for your Prince George's lot
Send the address and the kind of unit. We check it against the Prince George's rule and the sprinkler question, then connect you with a licensed Maryland builder who already does ADUs here.