ADU Rules in Tucson, AZ (2026)
ADU rules, permit requirements, size limits, and fees for Tucson, AZ. Source-cited from official municipal code.
Yes, ADUs are allowed in Tucson, AZ.
Tucson, AZ permits accessory dwelling units (ADUs) on residential properties. ADUs — also called granny flats, in-law units, backyard cottages, or secondary suites — are secondary housing units on a single-family or multifamily lot. State and local law actively preempts local restrictions, making ADU approval a streamlined ministerial process. In Tucson, the Tucson Planning and Development Services Department (PDSD) handles ADU permit applications. Below you will find the current size limits, setbacks, fees, and timeline for building an ADU in Tucson.
ADU Size Limits
ADU Size Limits in Tucson: Detached ADU: up to seventy-five percent of the gross floor area of the single-family dwelling on the same lot or parcel or one thousand square feet, whichever is less (max height: Not verified — see Tucson UDC Article 6 DIMENSIONAL STANDARDS). Attached ADU: Not verified — see Tucson UDC for attached ADU size limits. Arizona does not have a JADU concept equivalent to California's Gov Code 65852.22. Tucson UDC limits ADU to 50% of primary dwelling or 1,200 sqft. University of Arizona proximity makes smaller (400-700 sqft) studio ADUs highly rentable to graduate students.
| Type | Max Size | Max Height |
|---|---|---|
| Detached ADU | seventy-five percent of the gross floor area of the single-family dwelling on the same lot or parcel or one thousand square feet, whichever is less · Verified June 4, 2026 · Source | See official source |
| Attached ADU | See official source | See official source |
Permit Fees
ADU Permit Fees in Tucson: Plan check fee: None. Building permit fee: None. Impact fees: None. School fees: None or N/A. Total estimated permit cost: Varies. Tucson Water connection fees for new water/sewer service (typically $1,500–$5,000 depending on meter size). Tucson Transportation Impact Fee may apply for new dwelling units. Fee schedule: https://www.tucsonaz.gov/pdsd/fees
| Fee Type | Amount |
|---|---|
| Plan Check | None |
| Building Permit | None |
| Impact Fees | None |
| School Fees | None |
| Total Estimate | None |
Permit Timeline
Tucson ADU Permit Timeline: Contact Tucson PDSD for ADU permit processing timeline — see tucsonaz.gov/pdsd Apply through the Tucson Planning and Development Services Department (PDSD) online permit portal. Phone: (520) 791-5550.
Setback Requirements
ADU Setback Requirements in Tucson: Front setback: follows zone standard. Side setback: 5 feet. Rear setback: 5 feet. Per Arizona HB 2297, municipalities cannot require rear or side setbacks greater than 5 feet for ADUs. Tucson's UDC was updated to reflect this maximum. Front setback follows primary dwelling line per applicable zone standard. R-1 zones typically require 25 ft front setback for primary dwellings.
Parking Requirements
Parking Requirements: Municipality may not require that a lot or parcel have additional parking to accommodate an accessory dwelling unit or require payment of fees instead of additional parking
Restrictions & Requirements
- ADU must be on same lot as primary single-family dwelling
- Maximum size: 50% of primary dwelling or 1,200 sqft
- One ADU per single-family residential lot per HB 2297
- Corner lots may have additional street-facing setback requirements
- Impervious surface and lot coverage limits apply per UDC zone
- Saguaro cactus protection: any ADU construction requiring excavation near a Saguaro requires AZ Game & Fish permit for relocation
How Many ADUs Are Allowed?
Number of ADUs Allowed in Tucson: Single-family lots: 1 ADU per single-family lot per Arizona HB 2297. Multifamily properties: ADUs allowed in some multifamily zones per Tucson UDC — consult PDSD for specific zone standards. Arizona HB 2297 (2024) requires at least 1 ADU to be allowed on lots with single-family dwellings in municipalities with populations over 5,000. Tucson's UDC may allow additional ADUs in some zones — contact PDSD for guidance.
Single-Family Lots
1 ADU per single-family lot per Arizona HB 2297
Multifamily Properties
ADUs allowed in some multifamily zones per Tucson UDC — consult PDSD for specific zone standards
State Law & Preemption
State Preemption: Arizona House Bill 2297 (HB 2297, effective September 14, 2024) provides partial state preemption of local ADU regulations. The law: removes owner-occupancy requirements statewide; requires municipalities to allow at least one ADU per single-family lot; prohibits minimum lot size requirements exceeding 50% of existing lot; limits rear and side setbacks to maximum 5 feet. Tucson updated its UDC Section 6.7.4 to comply with HB 2297.
Historic District Considerations
Historic District Requirements: Tucson has 7 historic districts where additional design review may be required for ADU construction. Design review approval is required before obtaining a building permit for properties in historic overlay zones. Tucson has 7 locally-designated historic districts including El Presidio, Barrio Historico (one of the oldest surviving barrios in the US), Armory Park, University Heights, Blenman-Elm, Iron Horse, and West University. Many properties feature Sonoran adobe architecture (distinctive flat-roofed adobe buildings with continuous walls to the sidewalk). The Historic Preservation Commission reviews exterior alterations in designated historic districts. Tucson's historic adobe buildings have specific restoration standards. Look up historic district boundaries at: https://www.tucsonaz.gov/pdsd/historic-preservation
Frequently Asked Questions
Can I build an ADU in Tucson?
Yes. Tucson, AZ allows accessory dwelling units. On a single-family lot you can build 1 ADU per single-family lot per Arizona HB 2297.
How big can an ADU be in Tucson?
The maximum size for a detached ADU in Tucson is seventy-five percent of the gross floor area of the single-family dwelling on the same lot or parcel or one thousand square feet, whichever is less square feet.
How long does it take to get an ADU permit in Tucson?
The typical ADU permit timeline in Tucson is Contact Tucson PDSD for ADU permit processing timeline — see tucsonaz.gov/pdsd.
Do I need extra parking for an ADU in Tucson?
Tucson parking rules for ADUs: Municipality may not require that a lot or parcel have additional parking to accommodate an accessory dwelling unit or require payment of fees instead of additional parking
Do I have to live on-site to have an ADU in Tucson?
Owner-occupancy requirement in Tucson: No familial, marital, employment or other preexisting relationship required between owner or occupant of single-family dwelling and occupant of accessory dwelling unit
Source: Tucson Unified Development Code Section 6.7.4 — Accessory Dwelling Units; Arizona HB 2297 (Laws 2024, Chapter 204). Last verified April 6, 2026. View source