Milwaukee ADU permit requirements
Last reviewed: June 22, 2026
Quick answer
Permitting an accessory dwelling unit (ADU) in Milwaukee, Wisconsin means pulling a building permit from the local authority that issues it. ArchPermit tracks 11 source-cited requirements (7 required, the rest conditional) for this jurisdiction. Submittals go through Land Management System (LMS, Accela). 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 Milwaukee. Every item links to its authoritative source; items that vary are flagged to confirm locally.
An ADU is a 'Limited Use' — allowed by-right provided the Chapter 295 zoning standards are met — in a broad set of districts (RS1–RS6, RT1–RT4, RM1–RM7, RO1/RO2, LB1–LB3, RB1/RB2, NS1/NS2, CS, IM). Owner-occupancy is mandatory at permit time: at least one owner of the existing principal dwelling must occupy it as their primary residence, documented by at least two of (vehicle registration, driver's license, WI state ID, voter registration, income-tax return, utility bill, gaming-credit eligibility). One ADU per property; Internal/Attached ≤1,000 sf, Detached ≤1,300 sf; a detached ADU needs its own separate sewer/water connection. Submit via the Land Management System (LMS). Code basis: the WI Uniform Dwelling Code.
- Building Permit Application (ADU)required
Application for a residential ADU; must be taken out by the homeowner or a WI- and City-of-Milwaukee-licensed contractor, filed via LMS or at the Development Center.
source · reviewed 2026-06-22 - Construction Drawings (plan set)requiredverify locally
Scaled drawings (1/8"=1' or larger) including elevations, floor plans, wall sections/footings/framing, and wall-bracing information. (Official sheets disagree on the required copy count — 3 vs 4.)
source · reviewed 2026-06-22 - Cost of Constructionrequired
Stated actual cost of materials and labor to build the unit (excluding HVAC, electrical, plumbing, finishes); used for valuation/fees.
source · reviewed 2026-06-22 - Electrical Permit (separate)required
A licensed electrician must obtain electrical permits for all electrical work.
source · reviewed 2026-06-22 - Plumbing Permit (separate)required
The homeowner or a licensed plumber must obtain plumbing permits.
source · reviewed 2026-06-22 - Proof of Owner Primary Residencerequired
Documentation that an owner occupies the existing principal dwelling as primary residence — at least two of: vehicle registration, driver's license, WI state ID, voter registration, income-tax return, utility bill, gaming-credit eligibility.
source · reviewed 2026-06-22 - Zoning Verification (property's district)required
Confirm the parcel's zoning district to verify ADU eligibility/standards before applying.
source · reviewed 2026-06-22 - Certificate of Appropriateness (HPC)conditional
If exterior work is involved and the property is in a locally-designated historic district, a Certificate of Appropriateness from the Historic Preservation Commission is required before issuance.
source · reviewed 2026-06-22 - Certified Survey of Propertyconditional
A certified survey showing the proposed construction and yard grades; required for Detached or Attached ADUs (those increasing lot coverage). (Guidebook specifies four copies.)
source · reviewed 2026-06-22 - Site Utility Plans (Detached ADU)conditional
Detached ADUs require separate Site Utility Plans (their own sewer/water connection) plus the associated site-work permits.
source · reviewed 2026-06-22 - Truss Drawings and Calculationsconditional
Truss shop drawings and calculations, submitted when the design uses trusses.
source · reviewed 2026-06-22