Bolthole Index

Pima County, Arizona

Building permits, zoning and septic rules in Tucson, Arizona

Tucson, Arizona requires a building permit and inspections for most residential projects, issued by the city's Planning & Development Services Department rather than Pima County1. Tucson sets its own zoning through its Unified Development Code2. Septic permits for homes without city sewer come from Pima County, even inside city limits3.

At a glance

Building permit
Required for most residential projects, issued by the City of Tucson1
Zoning
City zoning under the Unified Development Code; R-1 single-family lots start at 6,000 sq ft2
Septic
Pima County permits and inspects septic systems, including inside city limits3
Accessory dwellings
Two per parcel with a family dwelling, up to 1,000 sq ft4
RV living
Limited to mobile home park spaces that qualify, capped at 25% of spaces5
Owner-builder
Arizona exempts owner-occupants from contractor licensing; this does not waive a permit6
Building height (R-1)
25 ft maximum7
Property tax
Pima County's effective rate is 0.8%8

Who to call

Building permits

City of Tucson Planning & Development Services Department (PDSD)

Building permits, zoning and planning applications, and building inspections inside Tucson city limits, through the Tucson Development Center

(520) 791-5550

pdsdinquiries@tucsonaz.gov

201 N. Stone Avenue, 1st Floor

Also useful

City of Tucson PDSD residential permits

Residential and commercial building permit applications and the permit-exemption checker for Tucson

(520) 791-5550

pdsdinquiries@tucsonaz.gov

Septic permits

Pima County Onsite Wastewater Treatment Facilities

Septic construction and discharge authorizations and inspections, including for homes inside Tucson that lack a sewer connection

520-724-7400

Contact details are copied from each office’s official page and were checked against it on October 24, 2026.

Off-grid gear

Going off-grid in Tucson means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Tucson, Arizona?

Yes for most residential work. The City of Tucson requires a permit and inspections for most residential projects, including porches, additions and equipment such as air conditioners and water heaters1. The city also publishes a permit-exemption checker for projects that may not need one, so confirm with the Planning & Development Services Department before assuming a small job is exempt1.

Review speed matters when you plan a build: the city's standard review lane has a 30-day review goal and covers new building permits9.

Arizona's owner-builder exemption lets an owner who builds for their own occupancy skip contractor licensing, but that exemption does not itself remove any local building-permit requirement6. We could not confirm which building code edition the city has adopted or any Tucson-specific owner-builder rule; ask the department.

Who issues building permits in Tucson, and how do you reach them?

Inside Tucson city limits, the City of Tucson Planning & Development Services Department (PDSD) handles building permits, planning and zoning applications and inspections through the Tucson Development Center9. Call (520) 791-5550 or email pdsdinquiries@tucsonaz.gov; the Tucson Development Center is at 201 N. Stone Avenue, 1st Floor9.

For land outside city limits, use the Pima County page.

Does Tucson have zoning, and what does it mean for lot size, setbacks and height?

Tucson adopts and enforces its own Unified Development Code, and the numbers depend on the zoning district. In the main single-family district, R-1, the minimum lot size for one dwelling is 6,000 sq ft, and a two-unit lot needs 10,000 sq ft2. R-1 lot coverage tops out at 70% for single-family use10, and building height is capped at 25 ft7. A residential perimeter yard next to another residential zone is 5 ft11.

Front and street-side yards follow a separate section of the code that we have not confirmed, so check your parcel's district and yards with the PDSD before you design. The city's online map shows zoning districts by address or parcel9.

Can you build an accessory dwelling or tiny home in Tucson?

Accessory dwelling units are allowed. Tucson permits two accessory dwelling units on a parcel developed with a family dwelling, and one on a duplex parcel4. An ADU is limited to 75% of the principal dwelling's floor area, up to 1,000 sq ft, and may be 650 sq ft regardless of the main home's size; side and rear setbacks are 5 ft4.

We could not confirm how Tucson's code treats a stand-alone tiny home on wheels or a minimum dwelling size. Ask the PDSD before buying a lot for that purpose.

How do septic permits work in Tucson?

Most Tucson homes connect to city sewer, but where a home has no municipal sewer, Pima County regulates the septic system, even inside city limits3. Pima County must first issue a construction authorization before a system is built or replaced12. After a final field inspection, the county issues a discharge authorization before the system can be buried and used13.

The Tucson Code requires plumbing fixtures to connect to a public sewer or to an approved private sewage disposal system14. Pima County's inspectors can be reached at 520-724-740015.

Soil matters for lots on the edge of town: USDA rates about 33% of Pima County's soils as not limited for a conventional drain field, so many sites need a site evaluation or an engineered system16.

Can you live in an RV on your land in Tucson?

Tucson's confirmed RV rule covers mobile home parks. RVs may occupy no more than 25% of the spaces designed for mobile homes, and only where the park is in an MH-2 zone or was built before July 1, 1995, with a rental lease of at least one month5.

We could not confirm a rule for living in an RV on an ordinary residential lot, temporary camping, or short-term rentals inside the city. Call the PDSD at (520) 791-5550 before parking an RV as a residence9.

How do you build a home in Tucson? The steps, in order

  1. Look up your parcel's zoning district on the city's online map and check lot size, coverage, height and yards9.
  2. Confirm whether your lot has city sewer. If not, apply to Pima County for a septic construction authorization12.
  3. Check the permit-exemption page, then apply for your building permit through the Tucson Development Center online1.
  4. Expect plan review; the standard lane has a 30-day review goal9.
  5. Schedule inspections as work proceeds, and for septic request the county's final field inspection before the discharge authorization13.

What stays with Pima County, and what to check before you buy in Tucson?

Septic permits stay with Pima County even inside the city3. For land outside city limits, the county's own rules apply; see the Pima County page. Pima County's effective property tax rate is 0.8%8, and its typical home insurance premium is about $1,052 a year17.

Wells, floodplain development and driveway or curb-cut rules inside the city were not confirmed; ask the PDSD about floodplain and driveways, and the Arizona Department of Water Resources about wells.

Watch-outs

  • Tucson's building code edition, permit fees and inspection rules were not confirmed; ask the Planning & Development Services Department at (520) 791-55509.
  • Historic preservation zones, neighborhood preservation zones and landmarks require a permit and design review for any development1.
  • A county permit does not apply inside Tucson, and a city permit does not cover septic: Pima County issues those separately3.

Sources

  1. City of Tucson PDSD residential permits (tucsonaz.gov)
  2. Tucson Unified Development Code, Table 6.3-2.a: Dimensional standards for the R-1, R-2, R-3, MH-1, & MH-2 zones (Tucson), quoted and re-checked
  3. Onsite Wastewater Treatment Facilities, Pima County, AZ (Tucson), quoted and re-checked
  4. Tucson Unified Development Code, Section 6.6 Accessory uses, buildings, and structures (6.6.3 Residential uses) (Tucson), quoted and re-checked
  5. Tucson Unified Development Code, Section 4.9.7 Residential use group (Tucson), quoted and re-checked
  6. Persons not required to be licensed; penalties; applicability (Arizona statewide rule), quoted and re-checked
  7. Tucson Unified Development Code, Table 6.3-2.a: Dimensional standards for the R-1, R-2, R-3, MH-1, & MH-2 zones (Tucson), quoted and re-checked
  8. Effective property tax rate: Bolthole Index county data
  9. City of Tucson Planning & Development Services Department (PDSD) (tucsonaz.gov)
  10. Tucson Unified Development Code, Table 6.3-2.a: Dimensional standards for the R-1, R-2, R-3, MH-1, & MH-2 zones (Tucson), quoted and re-checked
  11. Tucson Unified Development Code, Table 6.3-2.a: Dimensional standards for the R-1, R-2, R-3, MH-1, & MH-2 zones (Tucson), quoted and re-checked
  12. Onsite Wastewater Treatment Facilities, Pima County, AZ (Tucson), quoted and re-checked
  13. Onsite Wastewater Treatment Facilities, Pima County, AZ (Tucson), quoted and re-checked
  14. Tucson Code Sec. 16-11, Building interior (Tucson), quoted and re-checked
  15. Pima County Onsite Wastewater Treatment Facilities (pima.gov)
  16. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  17. Typical home insurance premium: Bolthole Index county data

Written October 24, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

Answers from the rulebook for Tucson

Tucson’s own rules

  • Minimum lot sizeSpecified

    Single-family dwelling on an R-1 zoned lot inside Tucson city limits (main single-family district)

    • Nonresidential uses in R-1 carry their own lot size exceptions (table 6.3-2.b); not summarized here.
    • Table amended by ord. 12219, 12/16/2025 per the table note.
    • Residential density in R-1 is stated as sf: 1/6,000 sf.

    minimum lot size, single-family dwelling (1 unit): >= 6000 sq ft (two-unit single-family use requires 10,000 sq ft; nonresidential uses see exceptions)

    “lot size / site area (minimum) sf (1 unit): 6,000 sf sf (2 units): 10,000 sf”
  • SetbacksSpecified

    Residential use on an R-1 zoned lot inside Tucson city limits, perimeter yard against an adjoining residential zone

    • Front street perimeter yard and street-side yards are set in section 6.4.5.c, which was not opened; no front-yard value is stated here.
    • Nonresidential uses adjacent to residential zones use 10 ft or 3/4(h), whichever is greater, per the table.
    • Figure on the table notes the greater of the two dimensions applies for nonresidential uses.

    perimeter yard, residential use adjoining residential zone: >= 5 ft (front street and other street yards per section 6.4.5.c (not captured))

    “res use res. zone 5' 5' 5' 5' 5' res use nonres zone 5' 5' 5' 5' 5'”
  • Lot coverageSpecified

    Single-family use on an R-1 zoned lot inside Tucson city limits

    • Nonresidential uses carry exceptions in table 6.3-2.b (lot coverage varies by use, e.g., 15% or 60%).

    maximum lot coverage, single-family: <= 70 % (nonresidential uses see exceptions table)

    “lot coverage (maximum) 70% sf: 70% mf: 75% nonres: see exceptions”
  • Building heightSpecified

    Single-family building on an R-1 zoned lot inside Tucson city limits

    • The flattened table row lists the R-1 value first; the 25 ft figure is read from that position.
    • Accessory structures in residential use are limited to 12 ft unless attached to the principal structure (section 6.6.3.d, not re-quoted here).

    maximum building height, single-family: <= 25 ft

    “height (maximum) 25' 25' sf, civic uses, & admin/prof offices: 25' mf/nonres: 40' 25' 25'”
  • Living in an RVLimited

    RVs occupying spaces in a mobile home park inside Tucson city limits

    • Limited to 25% of the existing mobile-home spaces, and only where the park is in an MH-2 zone or was built before July 1, 1995.
    • Rental lease must be for no less than one month.

    share of existing mobile home park spaces that may be RVs: <= 25 % (MH-2 zone, or park built before July 1, 1995)

    “recreational vehicles may occupy no more than 25% of the existing spaces designed for mobile homes provided: a. the mobile home park is in an mh-2 zone, or the mobile home park was built prior to july 1, 1995. b. the rental lease is for no less than one-month.”
  • Accessory dwellingsLimited

    Accessory dwelling units on a parcel with a family dwelling inside Tucson city limits (two per parcel; one per duplex parcel)

    • Two accessory dwelling units are permitted per parcel developed with a family dwelling, except a multifamily development; a duplex parcel is permitted one.
    • Size limit: 75% of principal dwelling gross floor area, not to exceed 1,000 sq ft; an ADU may be up to 650 sq ft regardless of principal dwelling size.
    • Side and rear setback is five feet; an ADU is not the dominant use of the property.
    • Detached accessory buildings, including ADUs, are not permitted in the buildable area between the principal building and the front street lot line, with limited exceptions.
    • On a lot over one acre, one further ADU is permitted if one ADU on the lot is a deed-restricted affordable unit.
    • New detached ADU structures must have a high albedo roof (>60 SRI) or other cool roof technology per the ICC green construction code.
    • No vehicular parking is required for ADUs; ADUs are not subject to maximum residential density standards.

    accessory dwelling units per parcel with a family dwelling: <= 2 units (one per duplex parcel; one further if a restricted affordable unit exists on a lot over 1 acre) · ADU gross floor area as share of principal dwelling: <= 75 % (not to exceed 1,000 sq ft) · ADU gross floor area allowance regardless of principal dwelling size: <= 650 sq ft · ADU side and rear setback: >= 5 ft

    “an accessory dwelling unit is limited to 75% of the gross floor area of the principal dwelling, not to exceed 1,000 square feet of gross floor area. an accessory dwelling unit may be up to 650 square feet of gross floor area, regardless of the size of principal dwelling.”
  • Off-grid sanitationLimited

    Dwellings inside Tucson city limits without a public sewer connection

    • Plumbing must go to an approved private sewage disposal system, which Pima County permits as an onsite septic system where no municipal sewer serves the home.
    “all plumbing fixtures shall be connected to a public sewer system or to an approved private sewage disposal system”
  • Mandatory utility hookupConditional

    Dwellings inside Tucson city limits: plumbing must connect to public sewer or an approved private sewage disposal system; a dwelling must have an adequate potable water supply.

    • Sewer: public sewer system or approved private sewage disposal system; the opened text sets no distance threshold for mandatory connection to an available public sewer.
    • Water: every dwelling must have an adequate potable water supply (the water source is not specified in the quoted text).
    • Section 16-11 is a housing-code maintenance standard; new-construction connection rules were not located on opened pages.
    “(4) all plumbing fixtures shall be connected to a public sewer system or to an approved private sewage disposal system, with the connections free from leaks, blockages, or other defects.”

Rules another office applies inside Tucson

Tucson does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.

  • Who permits septicCounty (with conditions)

    Onsite septic systems on lots inside Tucson city limits where the home is not connected to a municipal sewer; Pima County regulates them countywide, including inside Tucson city.

    • Applies only where the home is not connected to a municipal sewer system.
    • Recorded as countywide because the schema does not allow municipality-specific geography for a county authority; Tucson city does not itself regulate septic per the opened pages.
    “pima county regulates the construction (including replacement), ownership transfer, and closure of septic systems.”
  • Septic permitRequired

    Construction, replacement or use of a septic system serving a home inside Tucson city limits where the home is not connected to a municipal sewer

    • Pima County must first issue a construction authorization before the system is built or replaced.
    • A discharge authorization follows a final field inspection (see septic-inspection claim).
    • Design must conform to the Arizona aquifer protection permit rules and Pima County Code title 7 as stated on the county page.
    “pima county must first issue a construction authorization for the facility before it can be constructed or replaced.”
  • Septic inspectionRequired

    New or replaced septic systems serving homes inside Tucson city limits where the home is not connected to a municipal sewer

    • Final field inspection by Pima County is a precondition to the discharge authorization.
    “then, after the facility passes a final field inspection, pima county must issue a discharge authorization before the facility can be buried and put into use.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Tucson or Pima County directly.

  • Building permit — New residential construction inside Tucson city limits
  • Owner-builder exemption — Owner-builder permit exemption inside Tucson city limits
  • Building code adopted — Building code adopted by the City of Tucson for residential construction inside city limits
  • Inspections — Building inspections for residential construction inside Tucson city limits
  • Certificate of occupancy — Certificate of occupancy for new homes inside Tucson city limits
10 more unanswered
  • Minimum dwelling size
  • Camping on your land
  • Tiny homes
  • Well permit
  • Agricultural exemption
  • Driveway access
  • Building in a floodplain
  • Short-term rentals
  • Permit fees
  • Permit process

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Unanswered questions are usually a sign that Tucson publishes no rule on the point, not that none exists. Pima County’s page lists the county offices to call.

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