ADU / Casita Cost in Las Vegas (2026)
What an accessory dwelling unit actually costs in Las Vegas and Clark County — garage conversions, attached casitas and detached ADUs — with line-item budgets and jurisdiction-by-jurisdiction permit notes.
Based on Build4U's actual 2025–2026 ADU and casita projects. NSCB license #0095372.
Quick answer
$74K – $330K+Most attached casitas land in the $145K – $230K band; detached ADUs in the $205K – $280K band.
Tier 1 — Garage conversion ADU
$74K – $130KConvert an attached 2-car garage (~400–500 sq ft) to a conditioned, code-compliant ADU with kitchenette and full bath.
| Demo + slab prep + insulation upgrade | $6K – $11K |
| Framing infill (garage door wall) + new entry | $4.7K – $8.5K |
| Mini-split HVAC + ductwork | $5.5K – $9.5K |
| Electrical sub-panel + circuits + lighting | $6K – $11K |
| Plumbing (bath + kitchenette) + new sewer tie-in | $8K – $14K |
| Kitchenette cabinets + counters + appliances | $6K – $11.5K |
| Bathroom build-out (tile, vanity, fixtures) | $9.5K – $15.5K |
| Flooring + drywall + paint + trim | $8K – $12.5K |
| Permits + design + plan review + PM | $11.5K – $19.5K |
Tier 2 — Attached casita / addition ADU
$145K – $230KNew 500–800 sq ft conditioned space attached to the main house. Full bedroom, bath, living and kitchen or kitchenette.
| Foundation (slab or stem-wall) | $11.5K – $22K |
| Framing + roofing + exterior finish to match house | $27K – $45K |
| HVAC (dedicated zone or new mini-split system) | $8K – $14K |
| Electrical sub-panel + full circuits + lighting | $9.5K – $17K |
| Plumbing (kitchen + bath) + utility tie-ins | $11.5K – $22K |
| Kitchen cabinets + counters + appliances | $11.5K – $23K |
| Bathroom build-out | $11.5K – $19.5K |
| Windows, doors, insulation, drywall, flooring, paint | $23K – $39K |
| Permits, engineering, plan review | $8K – $14K |
| Design + project management | $19.5K – $31K |
Tier 3 — Detached ADU
$205K – $330K+Fully independent 600–1,200 sq ft detached structure with its own kitchen, bath(s), entrance, parking and (often) utility metering.
| Site prep + foundation + grading | $19.5K – $35K |
| Full framing + roofing + exterior | $43K – $74K |
| Independent HVAC system | $11K – $17K |
| New electrical service drop OR sub-panel from main | $11.5K – $23K |
| Full plumbing + separate sewer lateral | $17K – $31K |
| Full kitchen | $15.5K – $31K |
| Bath(s) build-out | $15.5K – $31K |
| Windows, doors, insulation, drywall, flooring, paint | $31K – $55K |
| Fire sprinklers (if over jurisdictional threshold) | $4.7K – $11K |
| Permits, engineering, civil, plan review | $11.5K – $22K |
| Design + project management | $23K – $43K |
Zoning + permit notes by jurisdiction
- Clark County (unincorporated) — ADUs / accessory dwellings allowed on properly zoned residential lots with setback, parking and (often) owner-occupancy conditions. Plan review 4–8 weeks.
- City of Las Vegas — separate building department with its own ADU standards; expect plan review 3–6 weeks and stricter compatibility review in established neighborhoods.
- City of Henderson — own Building & Fire Safety dept; ADU plan review often 3–5 weeks. HOA-heavy communities (Anthem CC, MacDonald Highlands) typically require ARC approval before permit submittal.
- North Las Vegas — own rules and queue; verify zoning before design.
- Utility separation — separate electrical service drop adds $6K–$14K and 4–8 weeks of NV Energy coordination.
- Fire sprinklers — required over square-footage / occupancy thresholds set by the AHJ; adds $4.7K–$11K and a separate sub-trade.
Rules change. We confirm current code with the specific jurisdiction at design kickoff for every project.
Next step
We'll start with a zoning check and feasibility review for your specific lot — then an itemized estimate before design begins.
FAQs
How much does an ADU or casita cost in Las Vegas in 2026?
Garage conversions to a livable ADU run $74K–$130K, attached casitas (new conditioned space off the house) run $145K–$230K, and fully detached ADUs with kitchen, bath and parking run $205K–$330K+ depending on size, foundation and utility runs.
Are ADUs even allowed in Las Vegas?
Yes, but with caveats. Clark County and City of Las Vegas allow accessory dwelling units / casitas on properly zoned lots, with size, setback, parking and owner-occupancy requirements that vary by jurisdiction. Henderson and North Las Vegas have their own rules. Build4U handles zoning verification, plan submittal and inspections.
What's the difference between a casita and an ADU?
In Nevada usage, a casita is typically a guest house — may or may not have a full kitchen, often shares utilities with the main house. An ADU (accessory dwelling unit) is a fully independent living unit with its own kitchen, bath, entrance and utility metering. ADUs require more permits and code compliance; casitas are simpler.
Can I rent out an ADU in Clark County?
Long-term rental is generally allowed for permitted ADUs subject to current zoning code; short-term rental (Airbnb-style) rules have tightened significantly across Clark County, City of Las Vegas and Henderson. Always confirm current rules with the jurisdiction before building for rental income — they change.
How long does an ADU build take?
Garage conversions 12–18 weeks on-site. Attached casitas 18–28 weeks. Detached ADUs 24–36 weeks, plus 8–14 weeks of design, engineering and plan review before ground-break.
What drives ADU cost up the fastest?
Utility separation (separate panel, sub-meter, new sewer lateral), foundation type (slab vs raised), site work on sloped lots, fire-sprinkler requirements over a square-footage threshold, and full kitchens vs kitchenettes.
