Building Setbacks & Zoning in Washington County, WI (2026)
3 rules for unincorporated Washington County, Wisconsin.
Verified from official government sources
Setback Rules
In the unincorporated towns of Washington County, Wisconsin, new principal structures within the shoreland zone, land within 1,000 feet of a lake or 300 feet of a navigable river, must sit at least 75 feet back from the ordinary high-water mark. Setback averaging can reduce that minimum to as little as 35 feet where neighboring homes already sit closer to the water. Cities and villages set their own rules.
Washington County Shoreland Setback: 75 Feet
Some RestrictionsWashington County Code § 275-5A, B(1)(d)
Except as reduced under this section, all temporary and permanent structures shall be set back 75 feet from the OHWM of navigable waters to the nearest part of a building or structure. ... Where there are existing principal structures in both directions, the setback shall equal the average of the distances the two existing principal structures are set back from the OHWM ... The average setback ...
Structure Height Limits
In the unincorporated towns of Washington County, Wisconsin, Chapter 275 caps building height within 75 feet of the ordinary high-water mark at 35 feet to protect wildlife habitat and scenic views. The county has no general zoning height limit outside that shoreland band; beyond 75 feet from the water, height is set by each town's own zoning, not by the county code.
Washington County Shoreland Height Limit: 35 Ft
Some RestrictionsWashington County Code § 275-3C, § 275-7A(6)
To protect and preserve wildlife habitat and natural scenic beauty, on or after February 1, 2010, construction of a structure taller than 35 feet placed within 75 feet of the OHWM is prohibited. ... An existing structure that was lawfully placed when constructed, but does not comply with the required setback, may be vertically expanded unless the vertical expansion would extend more than 35 fee...
Lot Coverage Limits
Within 300 feet of a lake, pond or navigable stream in the unincorporated towns of Washington County, impervious surface is capped at 15% of the lot, rising to 30% for residential and 40% for commercial land on mapped highly developed shorelines.
Washington County Shoreland Impervious Surface Cap
Some RestrictionsWashington County Code § 275-11C, § 275-23B(1)
General impervious surface standard. Except as allowed in § 275-11D, E and F, allow up to 15% impervious surface on the portion of a lot or parcel that is within 300 feet of the ordinary high-water mark. ... Penalty. Any person, firm, association or corporation, including those doing work for others, who violates or refuses to comply with any of the provisions of this chapter shall be subject t...
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