Can I Build Deck in Milwaukee, WI? (2026)
Find out if you can build a deck in Milwaukee, WI. Rules, permit requirements, costs, and next steps.
Yes, you can build a deck in Milwaukee, WI — a permit is required.
Deck permit requirements in Milwaukee, WI govern decks, patios, and outdoor structures. The Milwaukee Department of Neighborhood Services (DNS) enforces building permit requirements for deck projects. The key factor determining whether you need a permit is height above grade and attachment to dwelling.
Deck Rules in Milwaukee
Deck Rules in Milwaukee: Permit required: Yes. When permit is required: All decks over 30 inches from grade. Milwaukee DNS permit required. Milwaukee's two-flat and flat-front architectural tradition means rear decks are common additions to older housing stock. Structural assessment important for second-story deck additions.
Costs & Fees
Deck permit fees in Milwaukee: $100-$500.
Timeline
2-4 weeks
Next Steps
Next steps for building a deck in Milwaukee: 1. Verify whether your project meets the permit threshold. 2. If a permit is required, contact the Milwaukee Department of Neighborhood Services (DNS) at (414) 286-2268 or https://city.milwaukee.gov/DNS. 3. Submit plans and pay applicable fees. 4. Schedule required inspections through the Milwaukee Department of Neighborhood Services (DNS).
Milwaukee Department of Neighborhood Services (DNS)
Phone: (414) 286-2268
Website: https://city.milwaukee.gov/DNS
Online Permits: https://city.milwaukee.gov/DNS/Permits
Frequently Asked Questions
What is a Polish Flat and how does it affect ADU rules in Milwaukee?
A Polish Flat is a distinctive Milwaukee architectural type — a two-story house where the main living floor is elevated above a lower-floor apartment, with the front foundation visible between the ground and the elevated porch. This type was developed by Milwaukee's Polish immigrant community in the early 1900s as a built-in ADU. Many Milwaukee properties already function as two-family homes because of this tradition. If your Polish Flat has a lower-floor unit, it may require proper permitting and a Milwaukee rental housing license to legally operate as a rental.
Can I rent out a room or my whole home short-term (Airbnb) in Milwaukee?
Yes. Milwaukee requires a Short-Term Rental License ($150/year) for rentals under 30 consecutive days. Wisconsin Act 59 of 2017 prevents Milwaukee from banning STRs of 7 or more consecutive days outright, though Milwaukee may impose licensing requirements, safety standards, and density limits. Wisconsin state sales tax (5%) applies to STR revenues. Contact Milwaukee DNS or the City Clerk for current licensing requirements.
Can I build an ADU (carriage house or in-law suite) in Milwaukee?
Yes. Milwaukee's Zoning Code allows detached ADUs (often called carriage houses) of up to 900 sqft in the rear yard of residential properties. One parking space is required unless you're near a transit corridor. No owner-occupancy requirement. A building permit from Milwaukee DNS is required, and occupied rental units need a Milwaukee rental housing license. Contact Milwaukee DNS at (414) 286-2268.
What is Wisconsin Act 59 and how does it affect Milwaukee STRs?
Wisconsin Act 59, enacted in 2017, partially preempts local short-term rental bans. It prohibits Wisconsin municipalities (including Milwaukee) from completely banning short-term rentals of 7 or more consecutive days in residential zones. Milwaukee can still regulate STRs through licensing, density limits, safety requirements, and fire code compliance — it just cannot impose an outright ban on 7-night-or-longer rentals. Rentals shorter than 7 nights retain more local regulatory flexibility.
What permits are needed to convert a Milwaukee basement into a legal apartment?
Converting a Milwaukee basement or lower-floor unit to a legal apartment requires a building permit from Milwaukee DNS for the construction/renovation work (electrical, plumbing, egress windows, ceiling height compliance), plus a Milwaukee Rental Housing License for the occupied unit. Minimum ceiling height for habitable space is typically 7 ft. Egress windows are required for basement bedrooms. Fire separation between units may be required. Contact Milwaukee DNS at (414) 286-2268 for a pre-application meeting.
Source: Milwaukee Department of Neighborhood Services (DNS) — Building Regulations. Last verified April 6, 2026. View source