It depends heavily on the source and the scope. As of October 2026, a local real-estate guide estimates a stick-built detached casita of 400 to 700 sq ft at about $90,000 to $180,000, while a national renovation company lists $200,000 to $450,000 for 400 to 800 sq ft. Garage conversions are usually the least expensive option.
What do 2026 sources say?
| Project | Published figure | Source |
|---|---|---|
| Detached casita, 400–700 sq ft | About $90,000–$180,000 ($180–$300 per sq ft) | Nevada Real Estate Group, July 2026 |
| Detached casita, 400–800 sq ft | About $200,000–$450,000 | Block Renovation, May 2026 |
| Garage conversion | About $45,000–$85,000 | Nevada Real Estate Group, July 2026 |
| Single-story addition | About $250–$450 per sq ft | Block Renovation, May 2026 |
These are published estimates, not our prices. The gap between sources likely reflects different assumptions about finishes, site work and what counts as "included."
What costs come on top of the structure?
- Design. Block Renovation puts architect fees at about 8% to 15% of construction cost; the local guide lists $4,000 to $12,000 for design and engineering.
- Permits. About $2,000 to $5,000, per the local guide.
- Utilities. The local guide lists $8,000 to $20,000 each for utility trenching and the sewer connection, and $3,000 to $6,000 for a panel upgrade.
- Cooling. A mini-split system at about $4,000 to $8,000, per the same guide.
- HOA review fees. The local guide cites $50 to $500 where an association charges one.
Why do two quotes for the same casita differ?
Scope. One builder may price the shell only; another may include drawings, HOA submittal, permits, trenching, the sewer tap, cooling and finishes. Ask for a written, itemized quote and compare each line, including how caliche or other underground surprises are handled.
What moves the price on a valley lot?
- Distance to the sewer line and whether the trench crosses a pool deck or hardscape.
- Soil. Caliche can slow excavation.
- Electrical capacity. Many homes need a panel upgrade for a second kitchen and cooling system.
- HOA design rules. Matching tile roofs and stucco finishes.
- Finish level. The biggest lever you control.
Sources, as of October 2026:
- Nevada Real Estate Group, “Building an ADU or casita in Clark County” (July 9, 2026), for local cost ranges and add-on costs.
- Block Renovation, “Home additions in Las Vegas: the full process guide” (May 25, 2026), for casita and addition figures.
- Block Renovation, “A Deep Dive Into ADU Construction Costs” (2026), for national garage conversion figures.