Everything homeowners ask about building an ADU in Las Vegas — answered with 2026 data.
Yes, ADUs are allowed in All residential zoning districts - U, R-E, R-D, R-1, R-SL, R-CL, R-TH, R-2, R-3, R-4 and R-MH - as a conditional use ("C" in the LVMC 19.12.010 land-use table, row added by Ord. 6963 sec. 6). Conditional means administrative approval when the LVMC 19.12.070 conditions are met - no Special Use Permit and no hearing (the SUP route of 19.12.040(B) is expressly disapplied). Not listed in P-O, O or any commercial district. Lots in a Form-Based Code district follow LVMC 19.09, and Summerlin's adopted development standards (rev. June 9, 2022, not amended by Ord. 6963) still describe a guest house/casita as one room, no stove, not rentable, in the EQR, ER, SF1, SF2 and SF3 land-use districts only - confirm with Planning (702-229-6301) which rule governs a Summerlin lot in Las Vegas, NV. The maximum size for a detached ADU is 50% of the principal dwelling's floor area. A detached ADU must meet the district's accessory-structure standards (LVMC 19.06.040(C)(8)): in R-1, R-SL, R-CL, R-TH, R-2, R-3, R-4 and R-MH the Table 2/3 accessory size limit is "not to exceed 50% of the floor area of the principal dwelling unit", and U, R-E and R-D carry the same 50% rule as an ADU footnote to their tables. All accessory buildings together may also cover no more than 50% of the rear yard, and total lot coverage stays within the district cap (50% in R-1). The separate 19.12.070 ceiling - no larger than the home's gross floor area - applies on top, so a detached casita is always the smaller of the two. Attached ADUs can be up to No more than the total gross floor area of the primary dwelling unit. Las Vegas has an ADU-friendliness score of 6/10. Check our full Las Vegas ADU rules page for complete zoning details.
ADU construction in Las Vegas typically costs $110,000-$230,000. The cost per square foot averages $180-$330. Garage conversions are more affordable at $50,000-$120,000, while prefab ADUs cost $80,000-$180,000. Permit fees add Square-footage based (Building & Safety 2020 Building User Fees, Table 3-A, effective July 1, 2021 and still in force). The city's Permit Fee Estimator carries a "Single-Family Casita with Kitchen" line at the R-3 single-family rates: for a wood-frame (Type V) casita up to 1,000 sq ft, plan check $500 + inspection/permit $933 + $55 administration = $1,488; a 1,200 sq ft unit is about $1,676 and a 1,500 sq ft unit about $1,961 (plan check adds $0.467 and inspection $0.477 per sq ft over 1,000). Zoning fees arise only if a standard cannot be met: Administrative Deviation $300; Variance $300 plus $500 notification; Special Use Permit $500 plus $500 notification; Zoning Verification Letter $100 (Department of Planning Fee Schedule, Resolution R-21-2008). Contractors need a Nevada license and a city business license before a permit issues to your budget. See our detailed Las Vegas ADU cost guide.
Detached ADUs in Las Vegas can be up to 50% of the principal dwelling's floor area. A detached ADU must meet the district's accessory-structure standards. Attached ADUs are limited to No more than the total gross floor area of the primary dwelling unit. Junior ADUs (JADUs) have a cap of No junior ADU category exists in Las Vegas. A unit built within the primary residence is simply a "Residential, Accessory Dwelling Unit" (the definition covers detached, attached or built-within units) and follows the attached-ADU rules; a second kitchen that is not an ADU is an "auxiliary kitchen", which must be inside the house, directly accessible from it and for household use only (LVMC 19.18.020). Maximum height is 2 stories or 35 ft, or the height of the principal dwelling, whichever is less, for a detached ADU in R-1, R-SL, R-CL, R-TH, R-2, R-3, R-4 and R-MH (Table 3, Accessory Bldg.). In U and R-E the limit is 2 stories or 35 ft, and the accessory building may not exceed the principal dwelling's height for any portion within 10 ft of a property line. Height is measured from average finished grade along the front to the coping of a flat roof or the midpoint between eaves and ridge of a pitched roof (LVMC 19.18.030). You are allowed up to 1 accessory dwelling unit per lot on a qualifying lot.
Rear setback: 3 ft minimum for a detached ADU in R-1, R-SL, R-CL, R-TH, R-D, R-2, R-3, R-4 and R-MH (Table 2, Accessory Structures); 5 ft in U and R-E. No setback is required from a property line that abuts an alley (LVMC 19.06.040(C)(3)). An attached ADU uses the house's rear setback instead (15 ft in R-1). Side setback: 3 ft minimum for a detached ADU in R-1, R-SL, R-CL, R-TH, R-D, R-2, R-3, R-4 and R-MH; 5 ft in U and R-E; plus a 6 ft separation from the main building in every district. Corner side yard: 15 ft in U, R-E, R-D and R-1, 10 ft in R-SL, R-CL and R-MH, 5 ft in R-2, R-3 and R-4. An attached ADU uses the house's 5 ft side setback. Front setback: A detached ADU may not sit in front of the primary structure unless it is a side-loaded garage used as an ancillary use or an ADU with side entry that does not encroach into the front setback area (LVMC 19.06.040(C)(2)). An attached ADU meets the district front setback (20 ft in R-1, 25 ft in R-D, 15 ft in R-SL, 50 ft to a public street in U and R-E). 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 beyond the spaces required for the house (LVMC 19.12.070, Ord. 6963 sec. 7). That is the most Nevada AB 396 lets a city require; the code does not allow it to be waived for conversions or transit proximity. 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. LVMC 19.12.070 attaches only two conditions to the use (one unit per lot, no larger than the home), and the LVMC 19.18 definition lets the unit house "the occupants of the principal dwelling or their tenants, domestic employees or temporary guests", so the owner need not live in the main house to rent the casita on a long-term lease. The 2007-era condition that a Class I accessory structure could not be rented unless the principal dwelling was owner-occupied is gone. Exception to confirm: Summerlin's development standards (rev. June 2022) still say a guest house/casita "shall not be rented". 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 Las Vegas is typically Not published by the city for any residential permit type; Building & Safety posts no review-turnaround target. Plan on at least one correction cycle. A Building Express Plan Review (non-refundable $550 administrative fee plus $660 per hour above regular plan-review fees, pre-review appointment from $176 per hour, 702-229-6251) lets the design team sit with the plans examiners until approval. Las Vegas builders' 2026 guides (see cost sources) put a detached casita at roughly 3-5 months from application to permit and 7-12 months from design to move-in. Plan check: $500 for a Type V casita up to 1,000 sq ft, then $0.467 per additional sq ft (Building & Safety Fee Tables, R-3 use group, matched by the estimator's casita line); paid with the inspection fee and a $55 administration fee. Plans must be to scale, digitally signed, and stamped by a Nevada architect or engineer unless a city or SNBO regional standard detail is used; a Nevada-licensed contractor may also draw them. Structural calculations, a soils report for structures over 599 sq ft and 2018 IECC REScheck energy calculations are checked with the plans (Residential Submittal Guideline). Pre-approved plans availability: No city pre-approved or model ADU plan program exists as of September 2026. Every casita is a custom submittal drawn and stamped by a Nevada architect, engineer or licensed contractor; a prefabricated or manufactured unit is permitted under the R-3 "Prefabricated / Manufactured Dwelling" fee line ($176-$195 plan check) but still needs the full site, foundation and utility review.
Average ADU rental income in Las Vegas: 1-bedroom units rent for $1,200-$1,700/month, 2-bedroom units for $1,450-$2,000/month. Short-term rentals: No. Expected ROI: 5-7% annual return on cost.
The minimum lot size for an ADU in Las Vegas is None for the ADU: the former Special Use Permit condition that the lot exceed 6,500 sq ft was removed by Ord. 6963 (July 1, 2026). The district's own minimum lot size still applies to the lot itself (R-1 6,500 sq ft, R-SL 4,500, R-CL 3,000, R-TH 1,600, R-D 10,000, R-E 18,000, U 20,000), and on small lots the 50%-of-rear-yard accessory coverage rule and the lot-coverage cap decide the footprint. 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 Las Vegas, a garage conversion typically costs $50,000-$120,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.
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