ADU Permit Requirements in City of Washington, IN
Permit rules for the City of Washington, IN (ZIP 47501), county seat of Daviess County in southwestern Indiana. Permits issued by City of Washington Building Commission at 2113 Memorial Avenue, (812) 254-8208 (paper/in-person; no online portal). 2-mile ETJ around city; Daviess County for unincorporated parcels. IN framework: 2020 Indiana Residential Code (2018 IRC base + IN amendments) effective Dec 2019. Indiana Plumbing Code (Indiana Plumbing Commission, statewide). 2017 NEC. IECC 4A; frost depth 30 inches. Indiana has NO statewide GC license , Washington requires city contractor registration. Distinctive features: Indiana's 4th-largest Amish community (~14.6% of Daviess County); Crane NSWC federal installation defense workforce; White River + East Fork White River FEMA SFHA; INDOT permits for US-50/US-150/SR-57/SR-257; Duke Energy Indiana + CenterPoint Energy/Vectren utilities.
By Joey, Founder · Last verified May 1, 2026 · How we research →
When you need a ADU permit in City of Washington
IN (covering ZIP 47501), permits are issued by the City of Washington Building Commission, enforcing the 2020 Indiana Residential Code (incorporating the 2018 IRC (IN base), 2017 NEC, Indiana Plumbing Code (Indiana Plumbing Commission), Indiana Fuel Gas Code, Indiana Mechanical Code, and 2009 IECC w/ IN amendments with state amendments). IECC Climate Zone 4A. An accessory dwelling unit requires a full building permit, trade permits, and zoning approval. Confirm ADU is permitted in your zoning district before designing. Washington is the county seat of Daviess County, southwestern Indiana. Home to Indiana's 4th-largest Amish community (~14.6% of county); Amish horse-barn permits common east of town. Crane NSWC federal installation north in Martin County draws defense workforce. Eastside Park summer food-truck gathering is a community fixture. White River and East Fork White River drainages create FEMA SFHA in low-lying parcels.
ADU Permit Costs: City of Washington vs. Nearby
City of Washington comes in on the low side for Indiana. You're looking at $400 – $1,500 here, compared to the state average of $763 – $3,976.
| City | Estimated Fee |
|---|---|
| City of Washington | $400 – $1,500 |
| Indianapolis | $500 – $5,000 |
| Fort Wayne | $500 – $5,000 |
| Evansville | $500 – $5,000 |
Fees shown are estimates based on local building code data. Actual fees may vary based on project scope and valuation. See all City of Washington permit costs →
Zoning & HOA Considerations
ADU regulations vary dramatically by state and city. Many states (CA, OR, WA) have preemption laws that override local zoning restrictions. Check both state law and local zoning before designing.
If you live in an HOA community: hOAs have traditionally restricted ADUs, but state preemption laws in CA, OR, WA, and other states now limit HOA authority over ADUs. Check your state's ADU laws, your HOA may not be able to block construction even if CC&Rs appear to prohibit it.
Estimated Project Timeline in City of Washington
Here's a typical timeline for a adu project in City of Washington, IN:
Timeline is based on City of Washington's typical about 4 weeks permit processing time. Actual timelines vary by project complexity, completeness of application, and current department workload.
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Frequently Asked Questions
Estimated permit fees for ADU projects in City of Washington, IN range from $400 – $1,500. Fees vary based on project scope and valuation.
It depends on the specifics of your project. Some smaller ADU projects may be exempt from permit requirements, while larger ones typically require a permit. Use our free lookup tool to check your specific situation.
Working without a required permit in City of Washington can result in fines, stop-work orders, being required to remove completed work, and complications when selling your home. It's always best to check first.
Typical approval time for ADU permits in City of Washington is about 4 weeks. More complex projects may take longer if plan review is required.
If you live in an HOA community, you may need architectural review approval in addition to a building permit. HOA rules and city building codes are separate, you may need to satisfy both. Review your CC&Rs and submit to your HOA's architectural review committee before starting work.
Learn More About ADU Permits
Read our complete guide covering permit requirements, costs, common exemptions, and the application process.
Read ADU Guide →