Yes: Tempe allows one attached and one detached ADU by right on any lot with a single-family home under Zoning and Development Code Section 3-402 (Ordinance O2024.51, adopted November 2024 to comply with ARS 9-461.18). On lots under one acre an ADU may be up to 75% of the house's interior floor area or 1,000 sq ft, whichever is less; on lots of one acre or more the cap rises to 2,000 sq ft and a third unit is allowed if one is income-restricted. Rear, side and street-side setbacks are 5 ft, height follows the district limit (typically 30 ft), no extra parking is required and there is no owner-occupancy rule for long-term rentals. It takes a building permit through the Citizen Access Portal with a 5-10 working-day first-review target, and the Residential Rebate Program refunds 100% of the building permit and plan review fees after final inspection. Two-story ADU designs need a Use Permit under a December 17, 2025 Board of Adjustment decision.
In Tempe 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.
Zoning & Size Requirements [1][2][3][4]
Yes — Tempe allows ADUs. A detached ADU can typically be up to 1,000 sq ft under current Arizona and Tempe zoning rules.
See what this means for your lot — ask Tempe ADU builders for a quote →
| Allowed Zones | Any lot in a zoning district that allows residential use and that already contains a single-family dwelling (ZDC Section 3-402; ADU Development Guide Step 1). Lots with an existing duplex, triplex or apartment building are not eligible. HOA CC&Rs may still restrict ADUs (ARS 9-461.18(C)); most Tempe subdivisions have none. |
| Max Size (Detached) | Lots under 1 acre: 75% of the main house's gross floor area or 1,000 sq ft, whichever is less. Lots of 1 acre (43,560 sq ft) or more: 75% or 2,000 sq ft, whichever is less. Gross floor area is interior habitable area, excluding garages, carports and exterior storage (ZDC 3-402; ADU Development Guide Step 2). District lot coverage still applies, e.g. 45% in R1-6. |
| Max Size (Attached) | Same 75% / 1,000 sq ft rule (2,000 sq ft on lots of 1 acre or more). For a conversion of part of the house, only the remaining house area counts toward the 75% (ADU Development Guide Step 2). A legally built guest quarters converted to an ADU may exceed the cap under the Section 3-402(c)(2) exception cited on the city's ADU page. |
| Max Size (JADU) | No JADU category in Arizona or Tempe; a converted portion of the house is simply an attached ADU under Section 3-402. ADUs on lots under 1 acre are limited to 3 bedrooms; there is no bedroom limit on lots of 1 acre or more (ADU Development Guide Step 2). |
| Max Height | Same as the single-family height limit of the underlying district in ZDC Section 4-202 (typically 30 ft); ARS 9-461.18(B)(5) bars a stricter ADU-only cap. Since a December 17, 2025 Board of Adjustment decision the city requires a Use Permit for any two-story ADU design (city ADU page, September 2026). |
| Max Units | 2 per lot under 1 acre (1 attached + 1 detached); 3 on lots of 1 acre or more (1 attached + 2 detached) provided one unit is a restricted-affordable unit rented to households at or below 80% of area median income (ZDC 3-402; ADU Development Guide Step 1; ARS 9-461.18(A)(1)-(2)). |
Setback Requirements [1][2][3][4]
Tempe requires a rear setback of about 5 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 Setback | 5 ft minimum in all districts unless the district or overlay allows less (ZDC 3-402; ARS 9-461.18(B)(6)). Where the lot backs onto a dedicated public alley the rear setback is measured from the midpoint of the alley (city ADU page). |
| Side Setback | 5 ft minimum for interior side and street-side yards in all districts unless the district or overlay allows less (ZDC 3-402; ADU Development Guide Step 2); measured from the alley midpoint where a side yard abuts a dedicated public alley. |
| Front Setback | An ADU may not be placed in the front building setback; the front setback is the district standard for buildings in ZDC Section 4-202 (ADU Development Guide Step 2). Look up your district on the Tempe Zoning + Overlays Map. |
| Parking Required | No additional parking may be required for an ADU (ARS 9-461.18(B)(3)). If the ADU removes or alters an existing required space, replace it elsewhere on site or obtain a Use Permit to park in the front or street-side setback; alley-loaded spaces need a 23-ft backing distance (ADU Development Guide Step 2; City Code 21-3(4)). |
| Owner Occupancy | Not required for long-term rentals, and the city may not demand a family or employment relationship (ARS 9-461.18(B)(1)-(2)). One exception: an ADU built on or after December 20, 2024 that is licensed as a short-term rental requires the owner to live on the property (Tempe City Code 16A-213(k), authorized by ARS 9-500.39(B)(9)). |
| Min Lot Size | No minimum lot size; any lot with a permitted single-family dwelling qualifies (ZDC 3-402). Lot size only changes the numbers: under 1 acre = 2 ADUs and a 1,000 sq ft cap; 1 acre (43,560 sq ft) or more = 3 ADUs and a 2,000 sq ft cap. Existing guest quarters count toward the ADU total. |
Permit Process & Fees [5][6][7][8][9][10]
An ADU permit in Tempe goes through a standard permit review. Typical timeline: Target first residential plan review of 5-10 working days for projects under $500,000 and 4-6 working days per resubmittal (Building Safety Target Turn-Around Times, revised Aug 26, 2025); residential engineering review 5-15 working days. Permit fees: Building permit fee is valuation-based per City Code Fee Schedule Table 1-A, plus a plan review fee of 65% of the permit fee (Community Development Service Fees sheet); the Residential Rebate Program refunds 100% of both after final inspection.
| Approval Process | Building permit only, filed online through the Tempe Citizen Access Portal with a site plan, floor plans (including the existing house) and construction documents per the Residential Building Permit Checklist; no hearing or use permit for a one-story ADU (ARS 9-461.18(I)(5)). A two-story design needs a Use Permit (Board of Adjustment decision, Dec 17, 2025). Each ADU gets its own address (e.g. 1234 B) in 4-inch numbers. |
| Review Timeline | Target first residential plan review of 5-10 working days for projects under $500,000 and 4-6 working days per resubmittal (Building Safety Target Turn-Around Times, revised Aug 26, 2025); residential engineering review 5-15 working days. |
| Permit Fees | Building permit fee is valuation-based per City Code Fee Schedule Table 1-A, plus a plan review fee of 65% of the permit fee (Community Development Service Fees sheet); the Residential Rebate Program refunds 100% of both after final inspection. |
| Impact Fees | Tempe's fee page lists General Government Development Fees (impact fees) and water/sewer fees in the City Code fee appendix on Municode; no ADU-specific exemption is published, and impact, planning, fire and water/sewer fees are not covered by the Residential Rebate. Ask the Permit Center (480-350-4311) for the ADU amount; ARS 9-461.18(B)(3) bars parking in-lieu fees. |
| Plan Check | Plan review fee is 65% of the building permit fee, paid at submittal; it covers the first review plus two resubmittals (a fourth review costs extra). Submit through E-Plan Review; first-review target 5-10 working days. |
| Pre-Approved Plans | Yes, partly: the ADU and Single-Family Standard Plan Library (opened for ARS 9-461.20 submittals on July 1, 2026) held one pre-reviewed detached ADU plan as of Sept 20, 2026, a 600 sq ft studio/1-bath from the 2025 AARP ADU Design Challenge; the other nine challenge winners are not yet licensed. Plans are licensed from the designer, then submitted for a building permit. |
Get Free ADU Quotes in Tempe
Tell us about your project and we'll pass it to ADU builders serving Tempe. Free, no obligation — you choose who to work with. We don't have builders in every area yet; if nobody covers yours, we'll email you to say so.
Takes about a minute.
Up to 5 independent local ADU builders — never more, and we tell them nothing you don't submit here.
Compare quotes, verify license & insurance, hire (or don't). No spam either way.
🔒 Your info is secure. We share it only with contractors quoting your project. No spam, no obligation.
Just browsing? Search ADU builders near you by ZIP code.
Construction Costs [11][12][13][14]
Building an ADU in Tempe typically costs $150,000-$280,000 ($175-$350 per sq ft); a garage conversion runs $80,000-$150,000.
See what this means for your lot — ask Tempe ADU builders for a quote →
| Average Build Cost | $150,000-$280,000 |
| Cost per Sq Ft | $175-$350 |
| Garage Conversion | $80,000-$150,000 |
| Prefab ADU (Installed) | $150,000-$300,000 |
Finance Your ADU Project
Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders.
Some links on this page are affiliate links. We may earn a commission at no extra cost to you. Learn more
Rental Income Potential [15][16][17][18][19]
A 2-bedroom ADU in Tempe rents for around $1,700-$2,100/mo, an estimated 6-11% gross rental yield.
| Avg Rent (1 Bedroom) | $1,400-$1,750/mo |
| Avg Rent (2 Bedroom) | $1,700-$2,100/mo |
| Short-Term Rental | Yes, with a Tempe Short-Term Rental License (Ord. |
| Est. Annual ROI | 6-11% gross rental yield |
Explore Prefab ADU Options
Prefab ADUs can save 20-40% vs. traditional construction and cut build time in half.
Some links on this page are affiliate links. We may earn a commission at no extra cost to you. Learn more
Recent Law Changes
What's Changed Recently
- 2026-09-20: entry re-verified against the city's ADU page, the ADU Development Guide (Ord. O2024.51), the Building Safety fee and turn-around sheets, the Standard Plan Library and HUD FY2027 SAFMR; added the 2,000 sq ft cap on 1+ acre lots, the 3-bedroom limit, the two-story Use Permit rule, the 100% permit-fee rebate, review-time targets and the standard-plan count.
- December 17, 2025: Board of Adjustment decision; the city now requires a Use Permit for two-story ADU designs (city ADU page).
- July 1, 2026: Tempe opened its ADU and Single-Family Standard Plan Library for ARS 9-461.20 submittals; one 600 sq ft detached ADU plan (2025 AARP ADU Design Challenge winner) is pre-reviewed and available to license.
- July 1, 2026: annual CPI adjustment to the Community Development fee schedule (2026-2027 fees on the Building Safety Fees page).
- November 2024: Ordinance O2024.51 added ZDC Section 3-402 (Accessory Dwelling Units) and repealed the guest-quarters section to comply with ARS 9-461.18 (HB 2720); the city's STR owner-residency rule (City Code 16A-213(k)) applies to ADUs built on or after December 20, 2024.
Tips for Building an ADU in Tempe
- Cost basis: 2026 Phoenix-metro builder guides (Fenn Rogers May 2026, Rise Above 2026, Dwelling Index May 2026) put a mid-range 500-800 sq ft detached ADU at $150,000-$250,000, a custom unit at $250,000-$400,000+, a garage conversion at $80,000-$150,000 and permits/fees at $3,000-$12,000; Tempe planning staff quote local builders at $180,000-$260,000 for a high-quality ADU.
- Claim the Residential Rebate: finish within one year of permit issuance and apply to rebate@tempe.gov within 60 days of final inspection approval to get 100% of the building permit, plan review and SFR fees back; planning, fire and water/sewer fees are excluded (Ords. O2017.34 and O2017.35).
- Existing guest quarters count toward your ADU total, can be converted to a separately rentable ADU by building permit, and the converted unit may exceed the 1,000 sq ft cap.
- Keep it one story on a small lot: a two-story ADU now needs a Use Permit (hearing, extra fee and time); the 5-ft setback applies only to rear, side and street-side yards, never the front.
- Prefab, modular and tiny homes qualify as ADUs when placed on a permanent foundation and meet Tempe's building and rental-housing codes (City Code Chapter 21, Article II).
- Rent check: HUD's FY2027 Small Area FMR for Tempe ZIPs 85281-85284 is $1,560-$2,000 for a 1-bedroom and $1,810-$2,320 for a 2-bedroom (gross, including utilities), so a new ADU near ASU sits at the top of the metro range.
- Utility meters: the city defers to your provider on separate metering; Tempe Municipal Utilities confirmed existing water and sewer lines can absorb ADU demand, but grading and drainage requirements are site-specific (PermitCenter@tempe.gov).
- Cost basis (2026-09-20 re-verification): short term allowed: Yes, with a Tempe Short-Term Rental License (Ord. O2023.01: $250 per unit per year, $187.50 if issued July 1 or later; TPT licence, county assessor registration, $500,000 liability cover, neighbor notice) for stays of 29 days or less. If the ADU was built on or after Dec 20, 2024 the owner must live on the property (City Code 16A-213(k)).
ADU Builders in Tempe
Looking for an ADU builder in Tempe? ADU projects need a contractor experienced with local zoning, the permit process, and utility connections — not every general contractor has built one. We match Tempe homeowners with experienced local ADU contractors who provide free, no-obligation quotes. Getting at least three bids typically saves 20-40% on the same scope.
Sources & References
All data on this page is sourced from official government records and verified market data. View our full methodology.
- Accessory Dwelling Units (ADUs) - City of Tempe Planning (FAQ: standards, guest quarters, STR owner-residency, standard plans) government — Accessed 2026-09-20
- ADU Development Guide - City of Tempe Community Development (Ord. O2024.51; eligibility, size, lot coverage, setbacks, bedrooms, parking, permits) government — Accessed 2026-09-20
- Tempe Zoning and Development Code Section 3-402 - Accessory Dwelling Units (Municode; codified text) government — Accessed 2026-09-20
- ARS 9-461.18 - Accessory dwelling units; regulation; applicability; definitions state_statute — Accessed 2026-09-20
- Building Safety Fees (2026-2027 fee schedule links) - City of Tempe government — Accessed 2026-09-20
- Community Development Service Fees - Plan Review and Building Permit Fees (valuation basis; plan review 65%) government — Accessed 2026-09-20
- Building Safety Target Turn-Around Times (revised Aug 26, 2025) government — Accessed 2026-09-20
- Residential Rebate Program - City of Tempe Building Safety government — Accessed 2026-09-20
- ADU and Single Family Standard Plan Library - City of Tempe Building Safety government — Accessed 2026-09-20
- ARS 9-461.20 - Preapproved housing design plans (Class 4 ADU plans from July 1, 2026) state_statute — Accessed 2026-09-20
- ADUs in Arizona: Rules, Costs, What to Know (2026) - Fenn Rogers Custom Homes (updated May 12, 2026) industry — Accessed 2026-09-20
- How Much Does It Cost to Build a Casita in Arizona? (2026 Guide) - Rise Above Remodeling industry — Accessed 2026-09-20
- Prefab Modular ADU: 2026 Costs, Code Paths & Lot Fit - Dwelling Index (updated May 27, 2026) industry — Accessed 2026-09-20
- Accessory Dwelling Units (ADUs) - City of Tempe Planning (local builder cost estimate $180,000-$260,000) government — Accessed 2026-09-20
- HUD FY2027 Small Area Fair Market Rent Schedule - Phoenix-Mesa-Chandler MSA ZIP table (Tempe ZIPs 85281-85284) Market Data — Accessed 2026-09-20
- Average Rent in Tempe, AZ - RentCafe (updated Aug 31, 2026) Market Data — Accessed 2026-09-20
- Tempe, AZ Rent Research - Zumper (updated Sept 19, 2026) Market Data — Accessed 2026-09-20
- Tempe Short-Term Rental License - City of Tempe Tax & License (Ord. O2023.01) government — Accessed 2026-09-20
- ARS 9-500.39 - Vacation rentals; short-term rentals; regulation (B.9 ADU owner-residency option) state_statute — Accessed 2026-09-20
Frequently Asked Questions
Can I build an ADU in Tempe?
How much does an ADU cost in Tempe?
How much can I rent an ADU for in Tempe?
Do I need parking for an ADU in Tempe?
How long does it take to get an ADU permit in Tempe?
Ready to Build in Tempe?
Get free, no-obligation quotes from top-rated ADU contractors in Tempe.
Get Free Quotes →Build ADUs in Tempe?
Homeowners read this page while planning, then ask us to connect them with a local builder. We pass those requests to builders who cover Tempe — a flat fee only on the leads you accept, no subscription, and you contract directly with the homeowner.
See who's waiting in Arizona →