Washington
ADU Pass helps homeowners in Washington, St. Landry Parish, Louisiana navigate the permit paperwork for building an accessory dwelling unit. This area covers 1 ZIP code.
Map
ADU details
ADU legality: unclear
Louisiana leaves ADU regulation to local municipalities under home-rule or Dillon-rule authority. Washington permits ADUs subject to local conditions per its zoning ordinance.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 150 | $1,800 | $34,500 | $36,300 |
| 600 | 600 | $1,800 | $138,000 | $139,800 |
| midpoint | 525 | $1,800 | $120,750 | $122,550 |
| maximum | 900 | $1,800 | $207,000 | $208,800 |
Fee breakdown
Viability (permitted uses)
- Long-term rental: yes Long-term rental of ADU generally permitted; landlord-tenant law and any city rental-registration ordinance apply.
- Short-term rental: with-restrictions STR rules vary by city. Washington regulates STRs separately from ADU permitting; check local STR ordinance and HOA covenants.
- Office rental: with-restrictions Detached office rental requires home occupation permit or rezoning.
- Home office: yes Home occupation permitted with restrictions on signage and customer traffic.
- Studio / workshop: yes Personal artist studio is a permitted accessory use.
- Agriculture: with-restrictions Limited urban agriculture permitted in residential zones; livestock varies by district.
- Relative support: yes Family-occupancy ADU explicitly permitted in single-family zones.
Utilities
- Water: Washington Water Utility · 30d connect · $4,500
- Sewer: Washington Sewer / Wastewater · 30d connect · $5,500
- Electric: Washington Electric Utility · 21d connect · $1,800
- Gas: Washington Gas Utility · 30d connect · $1,500
Property values & taxes
Construction timeline
Realistic total: best 7mo · typical 10mo · worst 16mo
Financing
State ADU loans:
Insurance impact
HOA prevalence & preemption
Louisiana has no HOA-ADU preemption; HOA covenants restricting ADUs are enforceable.
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
Legal history (timeline)
Current ordinance: City of Washington Municipal Code — Accessory Dwelling Units, adopted 2020-01-01, last amended 2024-04-01
- 2024-01-01 — City of Washington ADU code refresh (city-ordinance)
Conforming local-code amendments aligning with current Louisiana accessory-dwelling framework.
Effect: Codified permissive ADU standards consistent with state law and local zoning.
Louisiana state — ADU law and programs
State financing programs
Louisiana does not operate an ADU-specific statewide loan, grant, or forgivable-loan program. The Louisiana Housing Corporation (LHC) is the state housing finance agency and administers down-payment-assistance programs (Mortgage Revenue Bond Assisted, MRB Home, MRB Home Assisted), the LHC Preferred Conventional Program, the HOME Program (for development), the Rental Restoration and Development Program (RRDP), Weatherization Assistance, and HUD-funded affordable housing development. None target ADU construction directly. ADU costs may be financed through standard renovation or construction-loan products under LHC programs when the ADU is part of a qualifying primary-residence transaction.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Code
- 70589
Post Office
- 112 E Moundville St, 70589