Detroit ADU permit requirements
Last reviewed: June 22, 2026
Quick answer
Permitting an accessory dwelling unit (ADU) in Detroit, Michigan means pulling a building permit from the local authority that issues it. ArchPermit tracks 16 source-cited requirements (13 required, the rest conditional) for this jurisdiction. Submittals go through eLAPS / Accela Citizen Access + 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 Detroit. Every item links to its authoritative source; items that vary are flagged to confirm locally.
ADUs became permitted by the 'Let's Build More Housing' Chapter 50 text amendment (signed 10/16/2025) — by-right ONLY in the R2, R3, R4, R5, and R6 districts (explicitly NOT R1), accessory to a single-, two-, or small (≤3-unit) multiple-family dwelling; one ADU per zoning lot; gross floor area ≤ the smaller of 1,200 sf or 60% of the principal dwelling. The signed ordinance contains no owner-occupancy requirement — only a prohibition on rentals of 27 or fewer consecutive days. An applicant files a building permit (plus separate electrical/mechanical/plumbing trade permits) with BSEED; adding a dwelling unit may also require recording the change of use at the Wayne County Register of Deeds.
- Building Permit Application (Form P2)required
Completed building-permit application, filed via eLAPS/Accela.
source · reviewed 2026-06-22 - Details & General Notes Sheetrequired
Roofing system, masonry/concrete wall engineering & reinforcement, connection details, damp-proofing, and design dead/live loads.
source · reviewed 2026-06-22 - Electrical Planrequired
Separate electrical floor plan (fixtures, receptacles, switches, arc-fault protection); a separate electrical trade permit is also required.
source · reviewed 2026-06-22 - Elevationsrequired
All proposed elevations with materials, roof slopes/drains, attic ventilation, and hazardous-area safety glazing.
source · reviewed 2026-06-22 - Floor Plansrequired
Labeled rooms, doors, window sizes/types, egress windows/wells, attic/crawl access, garage-to-house fire separation, and stair details.
source · reviewed 2026-06-22 - Foundation Planrequired
Allowable soil bearing pressure, footing dimensions/depth, reinforcing, anchor bolts, and foundation details.
source · reviewed 2026-06-22 - Framing Plans (roof & floor)required
Size/spacing/span of all framing members, lumber grade/species, connections, and a headers/lintels schedule.
source · reviewed 2026-06-22 - Mechanical Planrequired
Separate mechanical plan: HVAC locations/capacity/fuel, registers, ductwork.
source · reviewed 2026-06-22 - Plot Plan / Site Planrequired
Lot size & shape, dimensioned property lines, all buildings, distances to property lines, streets & alleys, lot area, flood-plain status, and all utilities.
source · reviewed 2026-06-22 - Specificationsrequired
One set of specifications submitted for plan review.
source · reviewed 2026-06-22 - Structural Calculationsrequired
One set of structural calculations submitted with the plans.
source · reviewed 2026-06-22 - Three Complete Sets of Plans (to scale)required
Three complete plan sets drawn to scale, submitted for plan review.
source · reviewed 2026-06-22 - Trade Permits (electrical, mechanical, plumbing)required
Separate trade-permit applications (Forms C4/C3/C5) in addition to the building permit.
source · reviewed 2026-06-22 - Change-of-Use Recording (Wayne County Register of Deeds)conditionalverify locally
BSEED guidance: adding a dwelling unit may require recording the use change at Wayne County; exact applicability to a new detached ADU vs a conversion to confirm.
source · reviewed 2026-06-22 - Michigan Energy Code Compliance Worksheetconditional
Required for newly constructed dwellings (applies to new ADU construction).
source · reviewed 2026-06-22 - Truss Calculations (signed & sealed)conditional
Required when prefabricated trusses are used — signed and sealed by a Michigan-licensed architect or engineer.
source · reviewed 2026-06-22