Building an ADU in Nevada: what state law allows

What state law lets you build

AB 396 was approved on June 6, 2025, as Chapter 365 of the Statutes of Nevada, and it is now NRS 278.257. It says each county of 100,000 or more people and each city of 60,000 or more "shall adopt an ordinance that authorizes the development and use of an accessory dwelling unit on residential property." The bill's digest names the governments covered today: Clark and Washoe counties and the cities of Las Vegas, Henderson, North Las Vegas, Reno and Sparks.

An ADU is "an independent living space" on the same lot as the main home, and it can be attached, detached or built inside the house. "Residential property" means property zoned for single-family residential use.

The ADU must meet residential building, housing and health and safety codes. It does not have to meet codes for commercial buildings, "including, without limitation, any code that requires a fire sprinkler system in a commercial building." [1][2][3]

What covered cities and counties can't require

As a condition of approving an ADU, the local ordinance must not:

• prohibit separate kitchen facilities (a sink, refrigerator and a stove, range or oven);
• require more than one additional parking space, if the main home's parking and street parking meet the ADU's expected needs;
• require side or rear setbacks stricter than those for the main house;
• require public street improvements, except to repair a street damaged during construction or for public health and safety;
• prohibit you from renting the ADU as housing.

The ordinance may prohibit using the ADU "as transient lodging," so short-term rental rules are up to each city or county.

State law doesn't set a size limit, height limit or owner-occupancy rule, so those come from your local code. Local governments may offer "more favorable conditions," such as approving an ADU with just a building permit. The law does not authorize more than two ADUs on a property. [1]

The July 1, 2026 deadline

The ADU provisions took effect July 1, 2026. A covered county or city that had already adopted an ordinance consistent with the law before then did not need to adopt another one.

If a covered government did not adopt a consistent ordinance before July 1, 2026, the act says "accessory dwelling units are authorized on any parcel zoned for residential use without restriction." Ask your planning department whether its ordinance was adopted in time and how it applies to your lot.

For example, the City of Las Vegas amended its Unified Development Code with Ordinance 6963, which the city code dates July 1, 2026. See our Las Vegas ADU guide. [2][4]

Where the law doesn't apply

The rule applies only to counties of 100,000 or more and cities of 60,000 or more. Smaller cities and counties set their own ADU rules.

It also does not apply "in a region in a county or city in this State for which there has been created by interstate compact a regional planning agency" whose regional plan calls for regulating housing. If your property is in such a region, check with that agency and your county.

Unincorporated areas follow county rules, not city rules. In Clark County, unincorporated towns such as Paradise and Spring Valley are governed by the county. [1][2][5]

Tiny houses as ADUs

Under NRS 278.253, a county of 100,000 or more or a city of 150,000 or more must designate at least one zoning district where a tiny house may be classified as an ADU, one where it may be a single-family home, and one for tiny house parks. Smaller governments must designate at least one of those options.

A tiny house not on a permanent foundation gets a certificate of occupancy tied to its parcel; if you move it, you need a new one. See our backyard tiny house guide. [6]

HOAs and common-interest communities

AB 396 also changed Nevada's common-interest community law (NRS chapter 116), including rules about when an association can restrict renting units. The ADU section itself does not say whether a homeowners' association can restrict ADUs, so read your CC&Rs and ask your association before you design. [2]

Challenging a decision

AB 396 applies Nevada's standard planning appeal deadline to the ADU law: a court action seeking review of a final local decision must be filed within 25 days after notice of the decision is filed with the clerk or secretary of the governing body. [2]

Where local rules differ

Each covered city and county writes its own ordinance within these limits. Size, height, lot coverage and owner occupancy vary, so check your local code. See our Las Vegas ADU guide, and our guides to the ADU permit process, ADU costs and ADU financing. [1][4]

Nevada laws to know

• AB 396 (2025), NRS 278.257

  Requires large counties and cities to allow ADUs on single-family-zoned property and limits the conditions they can impose. [1][2][3]

• NRS 278.253 (2021), tiny houses

  Requires every county and city to adopt a tiny house zoning ordinance; counties of 100,000+ and cities of 150,000+ must include a district where a tiny house can be classified as an ADU. [6]

Questions people ask