Everything homeowners ask about building an ADU in Tucson — answered with 2026 data.
Yes, ADUs are allowed in Residential zones permitting single-family dwellings (by-right under HB 2720) in Tucson, AZ. The maximum size for a detached ADU is 75% of primary dwelling, up to 1,000 sq ft (minimum 650 sq ft guaranteed). Attached ADUs can be up to 75% of primary dwelling, up to 1,000 sq ft (minimum 650 sq ft guaranteed). Tucson has an ADU-friendliness score of 5/10. Check our full Tucson ADU rules page for complete zoning details.
ADU construction in Tucson typically costs $110,000-$220,000. The cost per square foot averages $145-$290. Garage conversions are more affordable at $55,000-$130,000, while prefab ADUs cost $80,000-$180,000. Permit fees add $3,500-$5,500 to your budget. See our detailed Tucson ADU cost guide.
Detached ADUs in Tucson can be up to 75% of primary dwelling, up to 1,000 sq ft (minimum 650 sq ft guaranteed). Attached ADUs are limited to 75% of primary dwelling, up to 1,000 sq ft (minimum 650 sq ft guaranteed). Junior ADUs (JADUs) have a cap of Not allowed. Maximum height is Matches single-family height limit in the same zone (generally up to 25 ft) — Confirm with Tucson Planning & Development Services. You are allowed up to At least 1 attached + 1 detached per lot by-right; additional detached ADU on lots 1+ acre if one unit is restricted-affordable — Confirm exact count with Tucson Planning on a qualifying lot.
Rear setback: 5 feet (limited to 5 ft from property line per HB 2720). Side setback: 5 feet (limited to 5 ft from property line per HB 2720). Front setback: Per zone front setback (ADUs permitted in front yards meeting the zone front setback) — Confirm with Tucson Planning. Note that garage conversions may be exempt from setback requirements if the existing structure is already within the setback area.
No additional parking required (effective Nov 21, 2024; ARS 9-461.18 / AZ HB 2720). 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 (HB 2720 prohibits owner-occupancy mandates for long-term rental). 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 Tucson is typically 90-120 days. Plan check: 4-6 weeks. Pre-approved plans availability: Not available.
Average ADU rental income in Tucson: 1-bedroom units rent for $1,100-$1,500/month, 2-bedroom units for $1,400-$1,900/month. Short-term rentals: Not permitted. Expected ROI: 6-8% annual return.
The minimum lot size for an ADU in Tucson is None - ARS 9-461.18 bars ADU lot-size restrictions stricter than the zone's single-family standards. 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 Tucson, a garage conversion typically costs $55,000-$130,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.