ADU Pass
Lyon County
ADU Pass helps homeowners in Lyon County, Nevada navigate the permit paperwork for building an accessory dwelling unit. We cover 6 cities and 7 ZIP codes in this county.
Map
County ADU details
County ADU ordinance
Lyon County permits accessory dwelling units (called Guest Houses or Detached Accessory Living Quarters in the code) in most residential and rural zoning districts subject to a maximum gross floor area of 1,200 sq ft and minimum parcel size that scales with the underlying district (typically 0.5 acre minimum for E-1 Estate, larger for A-1 Agricultural). Owner occupancy of either unit is required and short-term rental of the ADU is restricted outside the county's STR licensing regime.
County assessor
Assessment policy: Lyon County applies Nevada's annual reassessment system (NRS 361). When an ADU is added, the new improvement is appraised at replacement cost less depreciation and added to the parcel's taxable value as new construction. Nevada's 3% residential property-tax cap (NRS 361.4722) protects the existing assessment but the ADU's added value enters at full taxable value in its first assessment year and is subject to the 3% cap thereafter.
County overlays (3)
- wui-fire-zone — Fire-district defensible-space inspections gate Certificate of Occupancy on most WUI parcels. Lyon does not have a separate Class K wildfire overlay; WUI is the county's only fire-overlay layer.
- flood-zone — Lyon County requires 1 ft of freeboard above BFE for new residential construction in mapped Zone A/AE; ADUs are subject to this enhanced standard. The 2017 / 2023 high-water years prompted enforcement tightening.
- other — Parcel research for properties near these reservations should confirm jurisdiction (county vs. tribal vs. BIA trust). Permit filings for tribal-trust parcels go through the BIA Western Region Office in Phoenix, not Lyon County Community Development.
Known county issues (1)
- staffing-shortage — Lyon County Community Development has a small staff (single-digit plan reviewers) and the Dayton-Stagecoach-Silver-Springs growth corridor has caused intermittent permit-backlog spikes. Typical 75-day duration can stretch to 110-120 days during peak season (April-September).
Nevada state — ADU law and programs
State financing programs
Nevada Housing Division (NHD), under the Department of Business and Industry, does not operate an ADU-specific loan or grant product as of 2026-04-26. NHD's primary homeowner-facing program is Home Is Possible, providing first-time and qualifying homebuyers in Clark and Washoe counties up to 4% of the loan amount as a non-repayable grant for down payment and closing costs, paired with a 30-year fixed-rate first mortgage. The Home Is Possible For Heroes overlay serves teachers, military, first responders, and healthcare workers. NHD also issued $283.3 million of 2024 tax-exempt bonding authority for affordable-housing development (multi-family); separately, the Nevada Affordable Housing Assistance Corporation (NAHAC) administers federal Hardest Hit Fund and Homeowner Assistance Fund programs for delinquency relief. None of these is ADU-specific; ADU construction can be financed only as part of a qualifying primary-residence purchase or refinance.
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.