Casitas are part of Arizona building culture, and recent changes have made them easier to build. A 2024 state law (HB 2720) requires larger Arizona cities to allow accessory dwelling units on single-family lots. The details still vary city by city.
Step 1: confirm your rules
- City ADU standards: size limits, height, setbacks, parking, and whether it can be rented
- HOA CC&Rs, which can be stricter than city code
- Lot constraints: easements, hillside or ESL rules, and pool barriers
Step 2: budget the hidden items
- Utility trenching and possibly a sewer connection or septic review
- Electrical panel capacity
- Matching stucco and roof tile
- Impact or development fees in some cities
Step 3: get plans and bids
Most casitas need stamped plans or detailed drawings for permit review. Ask contractors whether they provide design-build service or work from your architect's plans. Typical cost ranges are on our additions and casitas page.