Baltimore ADU permit requirements
Last reviewed: June 22, 2026
Quick answer
Permitting an accessory dwelling unit (ADU) in Baltimore, Maryland means pulling a building permit from the local authority that issues it. ArchPermit tracks 14 source-cited requirements (10 required, the rest conditional) for this jurisdiction. Submittals go through Accela ePermits / ePlans (ProjectDox). These requirements were last reviewed June 22, 2026; confirm the exact forms and fees with the local permitting authority.
A source-cited checklist of what an ADU (accessory dwelling unit) permit package needs in City of Baltimore. Every item links to its authoritative source; items that vary are flagged to confirm locally.
Baltimore City has no by-right ADU use in its current zoning. Article 32 does not define 'accessory dwelling unit.' The only adjacent path is the § 15-504 carriage-house conversion (a carriage house existing on June 5 2017 may be subdivided into a detached dwelling ≥1,750 sf meeting rowhouse lot/yard rules, +1 parking, or a variance). Maryland's 2025 ADU Act (SB 891 / HB 1466) requires the City to authorize one ADU per detached single-family lot, with a conforming ordinance due Oct 1 2026, not yet adopted. Until then, adding a dwelling unit routes through the generic residential building permit + a Use & Occupancy permit and would generally need a zoning variance in single-family zones. Confirm the current ADU rules with DHCD.
- Cross-Sectionsrequired
A core required drawing.
source · reviewed 2026-06-22 - Elevationsrequired
A core required drawing.
source · reviewed 2026-06-22 - Floor Plans (to scale)required
A core required drawing.
source · reviewed 2026-06-22 - Foundation Planrequired
A core required drawing.
source · reviewed 2026-06-22 - Licensed Contractor / MHIC Licenserequired
Electrical/gas/HVAC-R/plumbing need licensed contractors; work on one- and two-family dwellings needs a Maryland Home Improvement Commission (MHIC) license registered in ePermits.
source · reviewed 2026-06-22 - Permit Application (Accela ePermits)required
Submit the One- and Two-Family Combo Permit application (building + trades) in the Accela ePermits portal.
source · reviewed 2026-06-22 - Roof Planrequired
A core required drawing.
source · reviewed 2026-06-22 - Scope of Workrequired
Full description of the work to be done.
source · reviewed 2026-06-22 - Site Plan (to scale)required
A core required drawing for residential new construction/addition.
source · reviewed 2026-06-22 - Use & Occupancy Permit (added dwelling unit)required
A new/changed dwelling-unit count requires a U&O permit; provide the existing & proposed use and number of dwelling units.
source · reviewed 2026-06-22 - Carriage-House Conversion Conditions (§ 15-504)conditionalverify locally
The only current code path resembling an ADU: a pre-June-5-2017 carriage house may be subdivided to a detached dwelling if ≥1,750 sf, meeting rowhouse lot/yard rules, +1 parking, or a variance.
source · reviewed 2026-06-22 - Deed / Title-Company Letter (owner mismatch)conditional
Required only if the ePermits owner data doesn't match SDAT. Upload a docketed deed or a title-company letter.
source · reviewed 2026-06-22 - Zoning Variance / Future ADU-Ordinance Complianceconditionalverify locally
No ADU use exists in Article 32 today; a second dwelling unit in a single-family zone would generally need a zoning variance, pending the Oct 1 2026 state-mandated ADU ordinance. Confirm the path with DHCD.
source · reviewed 2026-06-22 - ePlans (ProjectDox) Plan Reviewconditional
Required when the project exceeds the ePlans threshold (e.g. over 600 sf) per the ePlans submission matrix.
source · reviewed 2026-06-22
Baltimore ADU permit questions
- Do I need a permit to build an ADU in Baltimore?
- Yes. An accessory dwelling unit (ADU) in Baltimore requires a building permit. ArchPermit tracks 14 cited requirements for this jurisdiction (10 required, the rest conditional). Always confirm the exact forms, fees, and code edition with the local permitting authority that issues the permit.
- What does an ADU permit package require in Baltimore?
- Core required items include: Cross-Sections; Elevations; Floor Plans (to scale); Foundation Plan; Licensed Contractor / MHIC License; Permit Application (Accela ePermits), plus 4 more. Each requirement links to its authoritative source, and nothing is permit-ready until an independent licensed professional reviews and seals it.
- How are ADU permits submitted in Baltimore?
- Baltimore accepts permit submittals via Accela ePermits / ePlans (ProjectDox). ArchPermit prepares a draft package you can submit there after a licensed architect reviews and seals it.