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 1–2 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