Everything homeowners ask about building an ADU in Henderson — answered with 2026 data.
Yes, ADUs are allowed in Conditional use in four low-density single-family residential zones (Henderson Development Code Title 19, Sec. 19.9.3 Accessory Uses); in RS-6 a minimum 10,000 sq ft lot is required in Henderson, NV. The maximum size for a detached ADU is 25% of the main single-family home's square footage (excluding carports, garages, unfinished basements), max 1,000 sq ft per Review-Journal reporting; some 2026 secondary sources cite a 1,200 sq ft cap — confirm the current limit with Henderson Community Development. Attached ADUs can be up to Subject to the same 25% / 1,000 sq ft framework — confirm with Henderson Community Development. Henderson has an ADU-friendliness score of 3/10. Check our full Henderson ADU rules page for complete zoning details.
ADU construction in Henderson typically costs $130,000-$250,000. The cost per square foot averages $140-$280. Garage conversions are more affordable at $60,000-$140,000, while prefab ADUs cost $90,000-$200,000. Permit fees add Confirm with Henderson Development Services Center to your budget. See our detailed Henderson ADU cost guide.
Detached ADUs in Henderson can be up to 25% of the main single-family home's square footage (excluding carports, garages, unfinished basements), max 1,000 sq ft per Review-Journal reporting; some 2026 secondary sources cite a 1,200 sq ft cap — confirm the current limit with Henderson Community Development. Attached ADUs are limited to Subject to the same 25% / 1,000 sq ft framework — confirm with Henderson Community Development. Junior ADUs (JADUs) have a cap of Not a defined category in Henderson; internal ADUs follow standard accessory dwelling rules. Maximum height is Confirm with Henderson Community Development (Development Code 19.9.3). You are allowed up to 1 accessory dwelling per property on a qualifying lot.
Rear setback: Per underlying zoning district; minimum 6-ft separation from the main residence required — confirm exact district setbacks with Henderson Community Development. Side setback: Per underlying zoning district — confirm with Henderson Community Development. Front setback: Per underlying zoning district — confirm with Henderson Community Development. Note that garage conversions may be exempt from setback requirements if the existing structure is already within the setback area.
1 additional off-street space typically cited; Nevada AB 396 (2025) bars local ordinances from requiring more than 1 ADU space — confirm current standard with Henderson. Many cities and states have been relaxing ADU parking requirements in recent years. In California, no additional parking is required for ADUs near transit.
Not required — Henderson is the Vegas-area exception; occupancy is instead limited to no more than 4 unrelated persons per dwelling. Note that owner-occupancy rules vary by state law — California and several other states have eliminated this requirement for standard ADUs.
The ADU permit review timeline in Henderson is typically Confirm with Henderson Development Services Center. The plan check process takes approximately Confirm with Henderson Development Services Center. Pre-approved plans availability: No city pre-approved ADU plan program identified as of June 2026.
Average ADU rental income in Henderson: 1-bedroom units rent for $1,300-$1,650/mo/month, 2-bedroom units for $1,550-$1,900/mo/month. Short-term rentals: No — accessory dwelling rental agreements must exceed 30 days (per Review-Journal reporting); Henderson's separate short-term rental licensing rules apply to other property types. Expected ROI: 5-8% annual return.
The minimum lot size for an ADU in Henderson is 10,000 sq ft in RS-6; other eligible low-density zones generally have 10,000+ sq ft minimum lots. This applies to detached ADUs — garage conversions and JADUs may have different or no lot size requirements.
Garage conversions are one of the most popular and affordable ADU options. In Henderson, a garage conversion typically costs $60,000-$140,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.