ADU laws in Nevada

In plain words

Nevada passed a statewide ADU law in 2025. An accessory dwelling unit, or ADU, is a smaller second home on the same lot as a house. It can be inside the house, attached to it, or a separate backyard unit. The law is Assembly Bill 396, and its main rules took effect July 1, 2026. It applies to Clark and Washoe counties. It also applies to Las Vegas, Henderson, North Las Vegas, Reno and Sparks. Each of these places must have a local law that allows ADUs on single-family lots. That local law cannot ban a full kitchen in the ADU. It cannot demand more than one extra parking space when existing and street parking are enough. It cannot set stricter side or rear setbacks than for the main house. A setback is the required gap between a building and the property line. It cannot ban renting the ADU to a long-term tenant. It can ban short-term, hotel-style rentals. Some places may have missed the July 1, 2026 deadline. There, the state law says ADUs are allowed on residential lots without restriction. The law skips the Lake Tahoe area, which follows its own regional plan. It also skips smaller counties and cities, where local rules decide. The state does not set size limits, fees, or a fast-track approval process. Local codes set those. Rural ADUs can share a private well. That takes local approval, a water meter, and a yearly cap of 2 acre-feet. An acre-foot is about 326,000 gallons. You may be able to build an ADU if local rules and your property allow it.

The rules at a glance

What to do next

1. Find out whether your lot is in a covered area: unincorporated Clark or Washoe County, Las Vegas, Henderson, North Las Vegas, Reno or Sparks, and not inside the Lake Tahoe Basin.
2. Ask the city or county planning department for its current ADU ordinance and whether it was updated for NRS 278.257, which took effect July 1, 2026.
3. Read your HOA covenants (CC&Rs) before you design anything. AB 396 does not make HOAs allow ADUs, and Reno's code says ADUs may not conflict with private restrictions.
4. If the property uses a private well, ask the county about the approval and water meter that NRS 534.180 requires for an ADU.
5. If you hope to rent the ADU short term, check local transient-lodging rules first, since covered places may ban that use.

What your town still decides

Nevada counties and cities write their own zoning codes under NRS Chapter 278. AB 396 sets a floor only for the two largest counties and five largest cities, which together hold most of the state's people. Inside that floor, local codes still decide where ADUs go, how big they can be, minimum lot size, fees, design, and whether approval is handled by staff or needs a hearing. The state law does not require staff-level (ministerial) approval, though it expressly lets a county or city approve ADUs through a building permit alone. If a covered place failed to adopt a compliant ordinance before July 1, 2026, the statute says ADUs are allowed on any residentially zoned parcel without restriction. Building, housing and residential health and safety codes still apply, but ADUs do not have to meet commercial building codes such as commercial fire-sprinkler rules. Lawsuits over a local ADU decision must be filed within 25 days of the decision. AB 396 does not require homeowners associations to allow ADUs. Outside the covered areas, each county and city decides on its own, though all must offer some zoning path for tiny houses under NRS 278.253. Nevada's Legislature meets in odd-numbered years, so the next regular session starts in 2027.

Examples of local rules

• Reno: Reno's Land Development Code (Title 18, amended June 3, 2026) lists ADUs as allowed in nearly all residential districts. One ADU is allowed per lot, on lots of at least 5,000 sq ft, no taller than the main home, with one on-site parking space. Attached and detached ADUs must meet the main home's setbacks, and size caps vary by zone (for example, 1,600 sq ft or 50% of the main home in SF-3). Detached units must match the main home's materials and roof pitch, and ADUs may not conflict with private restrictions such as HOA covenants. Source
• Washoe County (unincorporated areas): Washoe County's Development Code (Article 306, text dated April 18, 2025) allows attached ADUs on lots of at least 5,000 sq ft and detached ADUs on lots of at least 12,000 sq ft, one ADU or guest quarters per parcel. Size is capped at the smaller of 50% of the main home or 1,500 sq ft (1,200 sq ft in some denser zones). One extra off-street space is required, with exceptions for small detached units on larger lots. On parcels of half an acre or less, a detached ADU needs an administrative review permit, and one served by a domestic well must have a water meter. The county posts this text on its ADU page; check for changes made after AB 396 took effect. Source

What we’re still confirming

• Whether Clark County, Las Vegas, Henderson, North Las Vegas and Sparks adopted new ADU rules by July 1, 2026 isn't confirmed; ask your city or county.
• Where a covered city or county missed that date, state law allows ADUs on residential lots 'without restriction,' and how far that phrase reaches hasn't been tested.

Laws, bills and citations

This is general information, not legal advice. Your town, village, city or county decides what can be built on your property. If something here looks out of date, email the team.