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ADU Rules in Phoenix, Arizona

Complete guide to building an Accessory Dwelling Unit in Phoenix — zoning, setbacks, permits, costs, and more.

Max Size: 75% of the primary home's gross floor area (interior habitable area), and no more than 1,000 sq ft on a lot of 10,000 sq ft or less; on a lot over 10,000 sq ft, the lesser of 3,000 sq ft or 10% of net lot area (ZO 706.A.8). A garage, carport or attached shade structure built as part of a detached ADU does not count toward its floor area but does count toward lot coverage Setbacks: 3 ft from an interior rear lot line for a detached ADU; 0 ft along a fully dedicated alley (706.A.4.b). Attached ADU: the house's rear setback, or a projection to 3 ft if under 15 ft tall. State law caps any ADU rear or side setback at 5 ft (ARS 9-461.18.B.6) No Parking Required Verified: 2026-09-19

Researched by ADU Zoning Hub · verified 2026-09-19 against Phoenix planning code and Arizona ADU law · methodology · 29 sources cited ↓

ADU Score: 7/10
Moderately friendly · how we score

Are ADUs allowed in Phoenix, AZ? [1][2][3][4][5][6][7][8]

Yes. Phoenix allows ADUs on most residential lots. A detached unit can be up to 1,000 sq ft, set 3 ft back from the rear line. No extra parking is required. Owner-occupancy is not required, so the unit can be rented out. A building permit is required and applications are reviewed administratively, without a public hearing.

Maximum size75% of the primary home's gross floor area (interior habitable area), and no more than 1,000 sq ft on a lot of 10,000 sq ft or less; on a lot over 10,000 sq ft, the lesser of 3,000 sq ft or 10% of net lot area (ZO 706.A.8). A garage, carport or attached shade structure built as part of a detached ADU does not count toward its floor area but does count toward lot coverage
SetbacksRear 3 ft from an interior rear lot line for a detached ADU; 0 ft along a fully dedicated alley (706.A.4.b). Attached ADU: the house's rear setback, or a projection to 3 ft if under 15 ft tall. State law caps any ADU rear or side setback at 5 ft (ARS 9-461.18.B.6) · Side 3 ft from an interior side lot line and 5 ft from a street-side lot line for a detached ADU (706.A.4.b). Attached ADU: the house's side setback, or a projection to 5 ft if under 15 ft tall
ParkingNo additional parking may be required for an ADU (ARS 9-461.18.B.3; city ADU process guide TRT/DOC/00192 FAQ). If you convert the garage or carport, the city's ADU Beginner's Guide says the house's off-street parking must be re-established elsewhere on the lot on a dustproof surface, outside the front setback
Owner-occupancyNot required. Either the house or the ADU may be rented long-term (90-day or month-to-month leases) with no family or employment relationship (ARS 9-461.18.B.1-2). Only exception: to hold a short-term rental permit on a property whose ADU was finaled on or after September 14, 2024, the owner must attest and prove they live on the property (City Code Ch. 10 Art. XVI, effective April 4, 2026)

Do I need a permit to build an ADU in Phoenix? [9][10][11][12][13][14]

Yes. Every ADU in Phoenix needs a building permit. Applications are handled administratively — no public hearing.

Permit feesValuation-based (PDD Fee Schedule, Ordinance G-7465, effective January 20, 2026, Table A): permit fee $703 on the first $50,000 plus $9 per $1,000 up to $200,000, then $2,053 plus $9 per $1,000; residential plan review is 80% of the permit fee when valuation exceeds $50,000 (100%, minimum $195, at or below); plot plan review $98; each extra utility meter $98. Examples: a $150,000 valuation is about $1,603 permit + $1,282 plan review + $98 = $2,983; $250,000 is about $2,503 + $2,002 + $98 = $4,603. Valuation is the higher of the city's square-foot valuation table or your contract price. Re-inspections after the first are $195 each
Typical timelineNot published as a fixed ADU figure. Planning & Development posts a monthly Plan Review Turnaround Times report (goal vs. actual, by plan type) on its Reports, Data and Turnaround Times page; plan on at least one correction cycle. Phoenix builders' 2026 guides quote 6-12 months from design start to move-in for a detached casita and 4-6 months for a garage conversion
Official Phoenix links:

Three things to know before you build in Phoenix

  • Do the size math first: the ADU is capped at 75% of the house's interior floor area, so a 1,200 sq ft house allows a 900 sq ft ADU even on a big lot; lots over 10,000 sq ft get the lesser of 3,000 sq ft or 10% of net lot area, so a 12,000 sq ft lot allows 1,200 sq ft
  • Check lot coverage before design: in R1-6 and R1-8 the limit is 50% plus 10% for an ADU (60% total), counting every roofed area on the Assessor's sketch (garages, covered patios, sheds). Unpermitted structures must be legalized first through pdd.ombudsman@phoenix.gov
  • Placement: a detached ADU can go 3 ft off interior side and rear lines (0 ft at a dedicated alley) but is then limited to 15 ft in height; pull it out of the required yards to use the full 2-story/30-ft district height without a use permit, and never put it in front of the house without one

Last verified 2026-09-19 against Phoenix planning code. How we verify

Phoenix allows two accessory dwelling units by right on any lot that has one single-family detached house (one attached plus one detached, or two detached), under Zoning Ordinance Sections 608.E.2 and 706.A as amended by Ordinance G-7317 (Z-TA-2-24, adopted November 20, 2024) to comply with Arizona's HB 2720 (ARS 9-461.18). Each ADU may be up to 75% of the main house's gross floor area, capped at 1,000 sq ft on lots of 10,000 sq ft or less and at the lesser of 3,000 sq ft or 10% of net lot area on larger lots. A detached ADU can sit 3 ft from interior side and rear lot lines and 5 ft from a street-side line, up to 15 ft tall inside those yards, and no extra parking, owner-occupancy or design-matching is required. The unit may be rented long-term, or short-term if the owner lives on the property. Approval is a plain building permit priced on construction value under the January 20, 2026 fee schedule, roughly $3,000-$4,600 in permit and plan-review fees for a $150,000-$250,000 build, and development impact fees apply only in the city's growth-area fee zones.

In Phoenix you will also hear an ADU called a casita — Arizona's ADU statute (A.R.S. §9-461.18) and most local codes use it. The rules on this page apply either way.

Outside city limits? If your property is in unincorporated Maricopa County (not within Phoenix's boundaries), different rules apply — see our Maricopa County (unincorporated) ADU rules.

Zoning & Size Requirements [1][2][3][4][5][6][7][8]

Yes — Phoenix allows ADUs. A detached ADU can typically be up to 1,000 sq ft under current Arizona and Phoenix zoning rules.

See what this means for your lot — ask Phoenix ADU builders for a quote →

Allowed ZonesEvery residential district, on a lot with no more than one single-family detached house: S-1, S-2, RE-43, RE-24 and R1-14 (ZO Sections 603-607) and RE-35, R1-18, R1-10, R1-8, R1-6, R-2, R-3, R-3A, R-4, R-4A, R-5 and residential PADs (ZO 608.E.2, use table condition pc2). Lots with a duplex, triplex, single-family attached or multifamily units get no ADU. Look up your district on the city's My Community Map
Max Size (Detached)75% of the primary home's gross floor area (interior habitable area), and no more than 1,000 sq ft on a lot of 10,000 sq ft or less; on a lot over 10,000 sq ft, the lesser of 3,000 sq ft or 10% of net lot area (ZO 706.A.8). A garage, carport or attached shade structure built as part of a detached ADU does not count toward its floor area but does count toward lot coverage
Max Size (Attached)Same formula: 75% of the primary home's gross floor area, capped at 1,000 sq ft (lot up to 10,000 sq ft) or the lesser of 3,000 sq ft / 10% of net lot area (lot over 10,000 sq ft). Only one attached ADU per lot (706.A.2.a); an attached ADU must share a common wall and foundation with the house, otherwise it is treated as detached (ZO 202)
Max Size (JADU)Phoenix has no junior ADU category. A self-contained unit carved out of the existing house (or a garage attached to it) is simply the one attached ADU allowed per lot and follows the same 75% / 1,000 sq ft limits
Max HeightDetached ADU inside a required rear or side yard: 15 ft, or more with a use permit under Section 307 (706.A.4.c). A detached ADU that meets the house's own setbacks may use the district height, 2 stories and 30 ft in R1-6 and R1-8 (Tables 612.A and 613.A). An attached ADU follows the house's height and setbacks, and may project into the rear or side yard only if it stays under 15 ft, 3 ft off the rear line and 5 ft off a side line (701.A.3.a(2)(d))
Max Units2 ADUs per lot with one single-family detached home (maximum one attached; two detached is allowed, and two ADUs joined to each other but not to the house count as detached). A third ADU is allowed when the net lot is at least 43,560 sq ft (1 acre) and at least one ADU is deed-restricted affordable housing (608.E.2.a; ARS 9-461.18.A.2). ADUs do not count toward density

Setback Requirements [1][2][3][4][5][6][7][8]

Phoenix requires a rear setback of about 3 ft for a detached ADU, and no additional parking is required. Owner-occupancy is not required — you can rent it out without living on the property.

Rear Setback3 ft from an interior rear lot line for a detached ADU; 0 ft along a fully dedicated alley (706.A.4.b). Attached ADU: the house's rear setback, or a projection to 3 ft if under 15 ft tall. State law caps any ADU rear or side setback at 5 ft (ARS 9-461.18.B.6)
Side Setback3 ft from an interior side lot line and 5 ft from a street-side lot line for a detached ADU (706.A.4.b). Attached ADU: the house's side setback, or a projection to 5 ft if under 15 ft tall
Front SetbackThe underlying district's front setback applies (706.A.4.b(4)); in conventional R1-6 that is 10 ft for the building and 18 ft from the back of sidewalk for a front-loaded garage (Table 613.A). A detached ADU may not sit between the house and the front lot line without a use permit (706.A.5)
Parking RequiredNo additional parking may be required for an ADU (ARS 9-461.18.B.3; city ADU process guide TRT/DOC/00192 FAQ). If you convert the garage or carport, the city's ADU Beginner's Guide says the house's off-street parking must be re-established elsewhere on the lot on a dustproof surface, outside the front setback
Owner OccupancyNot required. Either the house or the ADU may be rented long-term (90-day or month-to-month leases) with no family or employment relationship (ARS 9-461.18.B.1-2). Only exception: to hold a short-term rental permit on a property whose ADU was finaled on or after September 14, 2024, the owner must attest and prove they live on the property (City Code Ch. 10 Art. XVI, effective April 4, 2026)
Min Lot SizeNo minimum lot size for an ADU; any lot that legally holds one single-family detached home qualifies. Lot size instead sets the cap: 1,000 sq ft on lots up to 10,000 sq ft, 3,000 sq ft or 10% of net lot area above that (a 12,000 sq ft lot allows 1,200 sq ft). Lot coverage also binds: R1-6 and R1-8 allow 50% plus 10% for an ADU or attached shade structure, 60% total (Tables 612.A, 613.A); RE-43, RE-24, RE-35 and R1-14 allow 40% when every structure is one story

Permit Process & Fees [9][10][11][12][13][14]

An ADU permit in Phoenix goes through a ministerial, by-right review. Review time: not published as a fixed ADU figure. Planning & Development posts a monthly Plan Review Turnaround Times report (goal vs. actual, by plan type) on its Reports, Data and Turnaround Times page; plan on at least one correction cycle. Phoenix builders' 2026 guides quote 6-12 months from design start to move-in for a detached casita and 4-6 months for a garage conversion. Permit fees: Valuation-based (PDD Fee Schedule, Ordinance G-7465, effective January 20, 2026, Table A): permit fee $703 on the first $50,000 plus $9 per $1,000 up to $200,000, then $2,053 plus $9 per $1,000; residential plan review is 80% of the permit fee when valuation exceeds $50,000 (100%, minimum $195, at or below); plot plan review $98; each extra utility meter $98. Examples: a $150,000 valuation is about $1,603 permit + $1,282 plan review + $98 = $2,983; $250,000 is about $2,503 + $2,002 + $98 = $4,603. Valuation is the higher of the city's square-foot valuation table or your contract price. Re-inspections after the first are $195 each.

Approval ProcessBy-right building permit; a code-compliant ADU needs no public hearing, variance or use permit (ARS 9-461.18 'permitted use'; ZO 608.E.2, 706.A). Order of work: 1) confirm zoning on My Community Map and lot size and building footprints on the Maricopa County Assessor record; 2) obtain site-planning approval of a scaled plot plan showing setbacks and lot coverage; 3) submit the residential plan set through the SHAPE PHX portal or at the Residential counter, 200 W. Washington St., 2nd floor (ADU submittals are logged in for full review, not over the counter); 4) pay permit fees; 5) inspections (602-495-0800) and final. A Section 307 use permit is needed only to exceed 15 ft inside a required yard or to place a detached ADU in front of the house. Separate address on request from Addressing Services (602-256-3127); one combined water meter service is the standard
Review TimelineNot published as a fixed ADU figure. Planning & Development posts a monthly Plan Review Turnaround Times report (goal vs. actual, by plan type) on its Reports, Data and Turnaround Times page; plan on at least one correction cycle. Phoenix builders' 2026 guides quote 6-12 months from design start to move-in for a detached casita and 4-6 months for a garage conversion
Permit FeesValuation-based (PDD Fee Schedule, Ordinance G-7465, effective January 20, 2026, Table A): permit fee $703 on the first $50,000 plus $9 per $1,000 up to $200,000, then $2,053 plus $9 per $1,000; residential plan review is 80% of the permit fee when valuation exceeds $50,000 (100%, minimum $195, at or below); plot plan review $98; each extra utility meter $98. Examples: a $150,000 valuation is about $1,603 permit + $1,282 plan review + $98 = $2,983; $250,000 is about $2,503 + $2,002 + $98 = $4,603. Valuation is the higher of the city's square-foot valuation table or your contract price. Re-inspections after the first are $195 each
Impact FeesDepends on where the lot is. Under the Development Impact Fee schedule effective June 23, 2025, the established city ('Balance of City') pays no fire, police, parks, library, arterial or storm-drain impact fees; the growth-area zones (Northwest, Deer Valley, Northeast, Paradise Ridge, Estrella, Laveen, Ahwatukee) charge a single-family dwelling roughly $12,000-$35,000 in total. Citywide the schedule lists per-dwelling water treatment ($4,387), wastewater treatment ($1,071) and water resource acquisition ($2,009, off-project) fees for a single-family unit on a meter up to 1 in. The schedule does not say whether an ADU on the house's existing meter is assessed, so email impactfees@phoenix.gov with your APN before budgeting; a 1% administrative charge applies to any gross fee
Plan CheckFull residential plan review (no over-the-counter path for ADUs). Submit a plot plan with site-planning approval, floor plans, elevations, structural and energy-code documents per the Residential Plan Submittal Checklist, and note fire-rating requirements per IRC R302; no grading-and-drainage plan is required for an attached or detached ADU (TRT/DOC/00192). Extra reviews apply on hillside lots (slope over 1:10), historic properties and floodplain lots. State law bars the city from requiring a fire sprinkler or commercial-code compliance in an ADU (ARS 9-461.18.D)
Pre-Approved PlansIn progress. The city's ADU Standard Plan Library, built from the 2024 City of Phoenix / AIA Phoenix Metro design competition, listed four detached designs marked 'in review' on the city ADU page in May 2026; approved plans are free to Phoenix residents, must be used without modification and still need a plot/site plan. State law (ARS 9-461.20, from SB 1529 of 2025) requires Phoenix to offer at least three pre-approved ADU plans at 200, 600 and 1,000 sq ft from July 1, 2026 and to accept outside plan submissions; check the city ADU page for the current list

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Construction Costs [15][16][17][18][19][20]

Building an ADU in Phoenix typically costs $150,000-$280,000 ($200-$350 per sq ft); a garage conversion runs $80,000-$150,000.

See what this means for your lot — ask Phoenix ADU builders for a quote →

Average Build Cost$150,000-$280,000
Cost per Sq Ft$200-$350
Garage Conversion$80,000-$150,000
Prefab ADU (Installed)$155,000-$300,000

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Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders.

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Rental Income Potential [21][22][23][24][25][26]

A 2-bedroom ADU in Phoenix rents for around $1,500-$1,750/mo, an estimated Roughly 6-11% gross rental yield on a $150,000-$280,000 detached build at $1,300-$1,700/mo (before taxes, vacancy, insurance and financing).

Avg Rent (1 Bedroom)$1,150-$1,500/mo
Avg Rent (2 Bedroom)$1,500-$1,750/mo
Short-Term RentalYes, with a city short-term rental permit for each unit (City Code Ch. 10 Art. XVI; TPT license, $500,000 liability insurance, neighbor notice).
Est. Annual ROIRoughly 6-11% gross rental yield on a $150,000-$280,000 detached build at $1,300-$1,700/mo (before taxes, vacancy, insurance and financing)

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Recent Law Changes

What's Changed Recently

  • Ordinance G-7317 (Z-TA-2-24-Y, adopted by City Council November 20, 2024) rewrote ZO 706.A and 608.E.2 for HB 2720: two ADUs per single-family lot (a third on 1-acre lots with an affordable unit), detached-ADU setbacks cut to 3 ft interior/rear and 5 ft street side, the design-matching requirement and the ban on short-term-rental use dropped, and one-story lot coverage in RE-43, RE-24, RE-35 and R1-14 raised to 40%
  • Short-term rentals (City Code Ch. 10 Art. XVI, effective April 4, 2026): an STR permit on a property whose ADU was finaled on or after September 14, 2024 now requires a notarized attestation and proof that the owner lives on the property, as allowed by ARS 9-500.39.B.9
  • PDD Fee Schedule (Ordinance G-7465, approved December 17, 2025, effective January 20, 2026): valuation-based permit Table A, residential plan review at 80% of the permit fee above $50,000, $98 plot plan review, $195 re-inspection
  • Development Impact Fees and Water Resources Acquisition Fees updated (Council approval April 9, 2025, effective June 23, 2025): Balance of City still exempt from fire, police, parks, library, arterial and storm-drain fees; growth-area zones repriced
  • ARS 9-461.20 (SB 1529, Laws 2025 ch. 259): from July 1, 2026 every Arizona municipality must offer at least three pre-approved ADU design plans (200, 600 and 1,000 sq ft), post them online and accept outside submissions; Phoenix's Standard Plan Library from the 2024 AIA competition was still 'in review' on the city page in May 2026
  • HB 2928 (Laws 2025 ch. 217): extended ADU-by-right rules to counties (unincorporated Maricopa County) from January 1, 2026 and made technical edits to ARS 9-461.18; the 2026 session left ARS 9-461.18 unchanged

Tips for Building an ADU in Phoenix

  • Do the size math first: the ADU is capped at 75% of the house's interior floor area, so a 1,200 sq ft house allows a 900 sq ft ADU even on a big lot; lots over 10,000 sq ft get the lesser of 3,000 sq ft or 10% of net lot area, so a 12,000 sq ft lot allows 1,200 sq ft
  • Check lot coverage before design: in R1-6 and R1-8 the limit is 50% plus 10% for an ADU (60% total), counting every roofed area on the Assessor's sketch (garages, covered patios, sheds). Unpermitted structures must be legalized first through pdd.ombudsman@phoenix.gov
  • Placement: a detached ADU can go 3 ft off interior side and rear lines (0 ft at a dedicated alley) but is then limited to 15 ft in height; pull it out of the required yards to use the full 2-story/30-ft district height without a use permit, and never put it in front of the house without one
  • Converting the garage? No new ADU parking is required, but the city's guide expects the house's parking to be re-created elsewhere on the lot on a dustproof surface outside the front setback
  • Short-term rental: allowed with a city STR permit, but if the ADU is finaled after September 14, 2024 you must live on the property to hold the permit (rule in force April 4, 2026). An HOA's recorded CC&Rs can still ban ADUs; the state law only limits the city (ARS 9-461.18.C)
  • No fire sprinkler or commercial-code standard can be demanded for the ADU (ARS 9-461.18.D); one combined water meter is standard, and a separate address is available from Addressing Services. Budget the water/wastewater treatment fees and, in growth-area zones, full impact fees
  • Timeline: Phoenix builders' 2026 guides put design plus permitting at roughly 3-4 months and construction at 3-6 months, so plan on 6-12 months end to end for a detached casita; garage conversions run 4-6 months
  • Cost basis (2026-09-19 re-verification): avg build cost $150,000-$280,000 for a mid-range detached casita of 400-800 sq ft, from Phoenix-area builder guides (Rise Above Remodeling 2026: $150,000-$250,000; Fenn Rogers May 2026: $150,000-$250,000; a Phoenix casita builder's 2026 permit-ready models $169,500-$229,500); custom or high-finish units run $250,000-$400,000+ (Hochuli 2026: $300,000-$600,000) | cost per sq ft $200-$350 (Rise Above $150-$230 typical, $230-$300+ high-end; Fenn Rogers $200-$400+) | garage conversion $80,000-$150,000 (Rise Above, Fenn Rogers; $100-$175/sq ft) | prefab/turnkey $155,000-$300,000 (a Phoenix modular builder's 2024 turnkey list $155,000-$279,000 for 322-1,178 sq ft; Dwelling Index May 2026: factory unit is 40-60% of a $200,000-$400,000 finished project). Site utilities typically add $8,000-$20,000 and permits are separate
  • Cost basis (2026-09-19 re-verification): short term allowed: Yes, with a city short-term rental permit for each unit (City Code Ch. 10 Art. XVI; TPT license, $500,000 liability insurance, neighbor notice). Since April 4, 2026, if the property's ADU received its certificate of occupancy on or after September 14, 2024, the owner must submit a notarized attestation plus proof of address that they live on the property (ARS 9-500.39.B.9). ADUs finaled on or before September 13, 2024 are exempt

ADU Builders in Phoenix

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Sources & References

All data on this page is sourced from official government records and verified market data. View our full methodology.

  1. ARS 9-461.18 - Accessory dwelling units; regulation; applicability; definitions Government Data — Accessed 2026-09-19
  2. Phoenix Zoning Ordinance Section 706 - Accessory Uses and Structures (706.A Accessory Dwelling Units) Municipal Code — Accessed 2026-09-19
  3. Phoenix Zoning Ordinance Section 608 - Residential Districts (608.E.2 ADU land use condition) Municipal Code — Accessed 2026-09-19
  4. Phoenix Zoning Ordinance Section 613 - R1-6 Single-Family Residence District (Table 613.A setbacks, height, lot coverage) Municipal Code — Accessed 2026-09-19
  5. Z-TA-2-24-Y staff report and Exhibit A ordinance text (Ordinance G-7317), Phoenix Planning & Development, Sept 30, 2024 Municipal Code — Accessed 2026-09-19
  6. City Council Formal Meeting Nov 20, 2024, Item 60 - Ordinance Adoption - Accessory Dwelling Units - Z-TA-2-24-Y (Ordinance G-7317) Government Data — Accessed 2026-09-19
  7. Accessory Dwelling Units (ADU) | City of Phoenix Planning & Development (FAQ and Standard Plan Library) Planning Department — Accessed 2026-09-19
  8. Beginner's Guide to ADUs | City of Phoenix Planning & Development (PDF) Planning Department — Accessed 2026-09-19
  9. PDD Fee Schedule, Phoenix City Code Appendix A.2 (Ordinance G-7465, approved 12/17/2025, effective 1/20/2026) - Building Safety Plan Review and Permit Fees, Table A Government Data — Accessed 2026-09-19
  10. 2025 Development Impact Fee Update - Development Impact and Water Resource Acquisition Fee Schedules by land use and service area (effective 6/23/2025) Government Data — Accessed 2026-09-19
  11. Impact Fee Estimates | City of Phoenix Planning & Development Planning Department — Accessed 2026-09-19
  12. Accessory Dwelling Unit (ADU) - Residential Process, TRT/DOC/00192 | City of Phoenix Planning & Development Planning Department — Accessed 2026-09-19
  13. Reports, Data and Turnaround Times (Monthly Plan Review Turnaround Times Report) | City of Phoenix Planning & Development Planning Department — Accessed 2026-09-19
  14. Fees, Valuations and Assurances | City of Phoenix Planning & Development Planning Department — Accessed 2026-09-19
  15. How Much Does It Cost to Build a Casita in Arizona? (2026 Guide) | Rise Above Remodeling, Phoenix industry — Accessed 2026-09-19
  16. ADUs in Arizona: Rules, Costs, What to Know (2026) | Fenn Rogers Custom Homes, Mesa (updated May 12, 2026) industry — Accessed 2026-09-19
  17. ADU Cost in Phoenix (2026) | Hochuli Design & Remodeling Team, Scottsdale industry — Accessed 2026-09-19
  18. ADU Pricing & Investment - City of Phoenix permit-ready casita models | AZ ADU, Phoenix industry — Accessed 2026-09-19
  19. The Cost of Building an ADU in Phoenix, Arizona - turnkey modular pricing (July 2024) | Minimal Living Concepts industry — Accessed 2026-09-19
  20. Prefab Modular ADU: 2026 Costs, Code Paths & Lot Fit | Dwelling Index (updated May 27, 2026) industry — Accessed 2026-09-19
  21. HUD FY 2027 Schedule of Metropolitan & Non-Metropolitan Fair Market Rents - Phoenix-Mesa-Chandler, AZ MSA Government Data — Accessed 2026-09-19
  22. HUD FY 2027 Small Area Fair Market Rent Schedule - Phoenix-Mesa-Chandler, AZ MSA ZIP codes Government Data — Accessed 2026-09-19
  23. Zumper Phoenix, AZ Rent Research (median asking rents, updated Sept 19, 2026) Market Data — Accessed 2026-09-19
  24. RentCafe Phoenix, AZ Average Rent and Market Trends (Aug 31, 2026) Market Data — Accessed 2026-09-19
  25. Short-Term Rental Registry | City of Phoenix Planning & Development (ADU owner-residency attestation effective April 4, 2026) Planning Department — Accessed 2026-09-19
  26. ARS 9-500.39 - Limits on regulation of vacation rentals and short-term rentals (subsection B.9, ADU owner residency) Government Data — Accessed 2026-09-19
  27. HB 2720, Laws 2024 Chapter 196 (approved May 21, 2024) - accessory dwelling units; requirements Government Data — Accessed 2026-09-19
  28. HB 2928, Laws 2025 Chapter 217 - accessory dwelling units; requirements (counties; amendments to ARS 9-461.18 and 9-500.39) Government Data — Accessed 2026-09-19
  29. ARS 9-461.20 - Municipal housing; standard preapproved housing design plans (SB 1529, Laws 2025 Chapter 259) Government Data — Accessed 2026-09-19

Frequently Asked Questions

Can I build an ADU in Phoenix?

Yes. ADUs are allowed in Every residential district, on a lot with no more than one single-family detached house: S-1, S-2, RE-43, RE-24 and R1-14 (ZO Sections 603-607) and RE-35, R1-18, R1-10, R1-8, R1-6, R-2, R-3, R-3A, R-4, R-4A, R-5 and residential PADs (ZO 608.E.2, use table condition pc2). Lots with a duplex, triplex, single-family attached or multifamily units get no ADU. Look up your district on the city's My Community Map in Phoenix. The maximum size for a detached ADU is 75% of the primary home's gross floor area (interior habitable area), and no more than 1,000 sq ft on a lot of 10,000 sq ft or less; on a lot over 10,000 sq ft, the lesser of 3,000 sq ft or 10% of net lot area (ZO 706.A.8). A garage, carport or attached shade structure built as part of a detached ADU does not count toward its floor area but does count toward lot coverage. Owner-occupancy is not required, so you can rent out the ADU.

How much does an ADU cost in Phoenix?

ADU construction in Phoenix typically costs $150,000-$280,000. Garage conversions run $80,000-$150,000, and prefab ADUs cost $155,000-$300,000.

How much can I rent an ADU for in Phoenix?

Average ADU rents in Phoenix are $1,150-$1,500/mo for a 1-bedroom and $1,500-$1,750/mo for a 2-bedroom unit.

Do I need parking for an ADU in Phoenix?

No additional parking may be required for an ADU (ARS 9-461.18.B.3; city ADU process guide TRT/DOC/00192 FAQ). If you convert the garage or carport, the city's ADU Beginner's Guide says the house's off-street parking must be re-established elsewhere on the lot on a dustproof surface, outside the front setback. Check with Phoenix planning department for the latest Arizona ADU parking rules, as many states have relaxed requirements in recent years.

How long does it take to get an ADU permit in Phoenix?

Phoenix does not publish a standard ADU review timeline. Planning & Development posts a monthly Plan Review Turnaround Times report (goal vs. actual, by plan type) on its Reports, Data and Turnaround Times page; plan on at least one correction cycle. Phoenix builders' 2026 guides quote 6-12 months from design start to move-in for a detached casita and 4-6 months for a garage conversion. Permit fees: Valuation-based (PDD Fee Schedule, Ordinance G-7465, effective January 20, 2026, Table A): permit fee $703 on the first $50,000 plus $9 per $1,000 up to $200,000, then $2,053 plus $9 per $1,000; residential plan review is 80% of the permit fee when valuation exceeds $50,000 (100%, minimum $195, at or below); plot plan review $98; each extra utility meter $98. Examples: a $150,000 valuation is about $1,603 permit + $1,282 plan review + $98 = $2,983; $250,000 is about $2,503 + $2,002 + $98 = $4,603. Valuation is the higher of the city's square-foot valuation table or your contract price. Re-inspections after the first are $195 each.

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ADU Guides for Phoenix Homeowners

FAQ

Phoenix ADU FAQ

Answers to every common question about building an ADU in Phoenix — costs, rules, permits, rental income.

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Phoenix ADU Costs

Detailed cost breakdown: construction $150,000-$280,000, garage conversion $80,000-$150,000, plus ROI analysis.

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Garage Conversion ADU Guide

Complete guide to costs ($80K-$180K), impact fee savings, and permits for garage-to-ADU conversions.

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ADU vs Mother-in-Law Suite

Legal differences that affect what you can build, how you can use it, and rental rights.

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About this information: This page is an informational summary of publicly available regulations - it is not legal, financial, or professional advice, and it is not a substitute for confirming requirements with your local planning department. Rules change frequently; always verify current requirements before designing, budgeting, or building. Last verified: 2026-09-19. Contractors we introduce are independent businesses - verify license and insurance directly before hiring. Spotted an error? Tell us - we verify against primary sources and correct quickly.

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