An attached ADU is a complete living unit built onto your house with a separate entrance. As of October 2026, Nevada's AB 396 counts attached units as ADUs, and a covered jurisdiction cannot require side or rear setbacks for one that are stricter than those for the house.
Why choose attached over detached?
- Shorter utility runs. Water, sewer and power are steps away.
- Less yard used. Useful on newer valley lots with small rear yards.
- One roofline. HOAs often prefer an addition that reads as part of the house.
What makes it harder?
- The roof tie-in. Matching tile and keeping monsoon rain out at the joint.
- Fire and sound separation at the shared wall.
- Cooling. A separate system or zone so each household controls its own temperature.
What does an addition cost in Las Vegas?
Block Renovation's Las Vegas guide (May 2026) puts single-story additions with mid-range finishes at about $250 to $450 per sq ft, with architect fees of roughly 8% to 15% of construction cost. An ADU addition also carries a kitchen and bathroom, which sit at the higher end of that range.
Do I need HOA approval?
Usually, if you are in an association. Block Renovation's guide notes that HOA design review often takes 30 to 90 days after a formal submission. We prepare the HOA package along with the permit drawings. See the HOA guide.