Surprise adopted a full accessory dwelling unit article (Municipal Code Chapter 106, Article XI) on December 17, 2024, two weeks ahead of the state deadline in Arizona's casita law, and wrote it to defer to the statute wherever the two differ. ADUs are a permitted use reviewed ministerially by the Community Development Director — no hearing, no conditional use permit, and a 30-day clock on the completeness check — on any lot where the zoning allows a single-family home. One attached plus one detached unit per lot, 5-foot rear and side setbacks, no extra parking, and a cap of 1,000 sq ft or 75% of the house, whichever is less. The catch that is specific to Surprise: lots in the territory around Luke Air Force Base and the city's airports are excluded from ADU eligibility outright.
In Surprise 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]
Yes — Surprise allows ADUs. A detached ADU can typically be up to 1,000 sq ft under current Arizona and Surprise zoning rules.
See what this means for your lot — get 5 free quotes from Surprise ADU builders →
| Allowed Zones | Any lot or parcel where the zoning allows a single-family dwelling and that already contains a primary dwelling, provided adequate public utility services exist (Surprise Municipal Code §106-11.3.A.1, §106-11.4.A.1). Not permitted on a lot with a duplex or other multiple-family development (§106-11.4.A.1). Excluded outright: tribal land, land in the territory in the vicinity of a military airport or ancillary military facility (A.R.S. §28-8461 — Luke Air Force Base), and land in the vicinity of a general aviation or public airport (A.R.S. §28-8486) (§106-11.3.A.3) — as written, without the 65-decibel qualifier the state statute uses, so check your parcel with the city before designing |
| Max Size (Detached) | The lesser of 75% of the gross floor area of the existing single-family dwelling or 1,000 sq ft (Surprise Municipal Code §106-11.3.A.2); gross floor area takes the state definition — interior habitable area (§106-11.2) |
| Max Size (Attached) | Same cap — the lesser of 75% of the house's gross floor area or 1,000 sq ft (§106-11.3.A.2) |
| Max Size (JADU) | Not a category in Arizona — Surprise's article has no junior ADU designation |
| Max Height | The same height restrictions that apply to a single-family dwelling on the same lot, as set by the residential district in Chapter 106, Article II (§106-11.4.A.5); state law bars a stricter ADU height than the house's (A.R.S. §9-461.18(B)(5)) |
| Max Units | 2 per lot — one attached plus one detached ADU (§106-11.3.A.1.a-b). On a lot of 1 acre or more: one attached plus two detached, but only if at least one ADU is a restricted-affordable unit deed-restricted for 30 years to HUD maximum rents (§106-11.3.A.1.c, §106-11.7) |
Setback Requirements [1][2]
Surprise 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 | No less than 5 feet from the property line (§106-11.4.A.3.a); state law caps what the city may require at 5 feet (A.R.S. §9-461.18(B)(6)) |
| Side Setback | No less than 5 feet from the property line (§106-11.4.A.3.b) — the state-law ceiling |
| Front Setback | No less than the front setback permitted for the single-family dwelling on the same lot (§106-11.4.A.3.c) — the district standard in Chapter 106, Article II |
| Parking Required | None — no additional parking space or in-lieu parking fee may be required (§106-11.4.A.6; A.R.S. §9-461.18(B)(3)) |
| Owner Occupancy | Not required — the article is silent on who lives where, and under state law Surprise may not prohibit leasing or advertising either the house or the ADU as separate long-term rental housing, nor require any familial or other relationship between occupants (A.R.S. §9-461.18(B)(1)-(2)). Short-term rental of an ADU is allowed but licensed under a separate chapter — see the rental section |
| Min Lot Size | No ADU-specific minimum lot size — the same one-attached-plus-one-detached allowance applies below and above 1 acre (§106-11.3.A.1.a-b); a lot of 1 acre or more unlocks a third unit |
Permit Process & Fees [3]
An ADU permit in Surprise goes through a ministerial, by-right review. Typical timeline: 30 days for the completeness determination and 15 days per resubmittal are written into the code (§106-11.5.D.1); the substantive review time is not — confirm with Surprise Community Development. Permit fees: Building permit and plan review fees apply and are paid online through the city's permit portal — confirm current amounts with Surprise Community Development; no ADU-specific fee figure is published on a city page.
| Approval Process | Ministerial — approved by the Community Development Director without a public hearing, variance, conditional use permit, special permit or special exception (§106-11.5.B). A building permit is required before construction (§106-11.5.C). Staff must decide whether the application is administratively complete within 30 days and review a resubmittal within 15 days (§106-11.5.D.1); substantive review follows, with administrative adjustments possible under §102-4.6. A denial can be appealed under §102-2, limited to whether the objective criteria were met (§106-11.5.E); a finding that an ADU is not a permitted use goes to the Board of Adjustment (§106-11.3.B) |
| Review Timeline | 30 days for the completeness determination and 15 days per resubmittal are written into the code (§106-11.5.D.1); the substantive review time is not — confirm with Surprise Community Development |
| Permit Fees | Building permit and plan review fees apply and are paid online through the city's permit portal — confirm current amounts with Surprise Community Development; no ADU-specific fee figure is published on a city page |
| Impact Fees | Confirm with Surprise Community Development — the ADU article does not address development impact fees |
| Plan Check | Full review under the city's building codes, fire codes and public health and safety regulations (§106-11.3.A.1); a Self-Certification Building Permit Program exists for qualifying residential work. State law bars a commercial building code or a fire-sprinkler requirement for an ADU (A.R.S. §9-461.18(D)) |
| Pre-Approved Plans | No city pre-approved ADU plan library found — confirm with Surprise Community Development |
Get Free ADU Quotes in Surprise
Tell us about your project and we'll connect you with ADU builders serving Surprise. Free, no obligation — you choose who to work with.
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 [4]
Building an ADU in Surprise typically costs $120,000-$245,000 ($145-$270 per sq ft); a garage conversion runs $55,000-$135,000.
See what this means for your lot — get 5 free quotes from Surprise ADU builders →
| Average Build Cost | $120,000-$245,000 |
| Cost per Sq Ft | $145-$270 |
| Garage Conversion | $55,000-$135,000 |
| Prefab ADU (Installed) | $85,000-$200,000 |
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 [5][6][7]
A 2-bedroom ADU in Surprise rents for around $1,550-$1,950/mo, an estimated 6-9% annual return.
| Avg Rent (1 Bedroom) | $1,300-$1,650/mo |
| Avg Rent (2 Bedroom) | $1,550-$1,950/mo |
| Short-Term Rental | Yes, with a city licence: Surprise licenses short-term and vacation rentals under Municipal Code Chapter 26, Article X (Ordinance 2023-13), and the definition expressly includes an accessory dwelling unit. A licence, a 24-hour emergency point of contact, neighbour notification, insurance and posting on the property are required (§§26-257 to 26-264), plus Arizona TPT registration. The ADU article itself imposes no owner-occupancy condition on renting |
| Est. Annual ROI | 6-9% annual return |
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
- Ordinance No. 2025-43, adopted December 17, 2024, created Municipal Code Chapter 106, Article XI (Accessory Dwelling Units, §§106-11.1 to 106-11.7) ahead of the January 1, 2025 deadline in A.R.S. §9-461.18 — and states that if any provision conflicts with the statute, 'the state law shall control' (§106-11.1)
- Arizona HB 2720, codified at A.R.S. §9-461.18, requires every municipality over 75,000 people to allow at least one attached and one detached ADU as a permitted use wherever single-family homes are allowed — Surprise's population of about 167,600 (U.S. Census Bureau, 2024 estimate) puts it squarely inside the mandate
- State law bars the city from requiring extra parking or in-lieu fees, exterior design matching, a city-imposed restrictive covenant, or rear/side setbacks over 5 feet (A.R.S. §9-461.18(B))
- Surprise wrote the airport exclusions from the statute into its own eligibility test: lots in the territory around Luke Air Force Base, a general aviation airport or a public airport are not eligible for an ADU (§106-11.3.A.3)
- Short-term rentals, including ADUs, have been licensed citywide since Ordinance 2023-13 (April 18, 2023) — Municipal Code Chapter 26, Article X
Tips for Building an ADU in Surprise
- Check the airport map before anything else: the territory in the vicinity of Luke Air Force Base (A.R.S. §28-8461) covers part of Surprise, and a lot inside it is simply not eligible — no variance fixes that (§106-11.3.A.3)
- Measure your house before you design: the cap is the lesser of 1,000 sq ft or 75% of your home's interior habitable area, so a 1,200 sq ft house limits the casita to 900 sq ft
- You can build two ADUs by right — one attached and one detached — and a third on an acre or more if one is deed-restricted to HUD affordable rents for 30 years (§106-11.3.A.1, §106-11.7)
- Hold the city to its own clock: the code gives staff 30 days to tell you whether your application is complete and 15 days to check a resubmittal (§106-11.5.D.1)
- The 5-foot rear and side setback is a state-law ceiling, not a floor — Surprise cannot require more (§106-11.4.A.3; A.R.S. §9-461.18(B)(6))
- If you plan to rent nightly, get the short-term rental licence first — it is a separate process under Chapter 26 with neighbour notification and insurance requirements, and it applies to ADUs by name
- Check your plat for public utility easements early — an ADU may not encroach on an existing or planned easement without written consent from every easement holder and affected utility (§106-11.4.B)
ADU Builders in Surprise
Looking for an ADU builder in Surprise? ADU projects need a contractor experienced with local zoning, the permit process, and utility connections — not every general contractor has built one. We match Surprise 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.
- Surprise Municipal Code, Part II Land Development Ordinance, Chapter 106 Article XI — Accessory Dwelling Units, §§106-11.1–106-11.7 (Ord. No. 2025-43, 12-17-24) Municipal Code — Accessed 2026-09-06
- A.R.S. §9-461.18 — Accessory dwelling units; regulation; applicability; definitions state_statute — Accessed 2026-09-06
- Permits & Applications — City of Surprise Community Development Planning Department — Accessed 2026-09-06
- Angi — ADU Construction Cost Data (same source and access as the Peoria entry; West Valley ranges applied) Market Data — Accessed 2026-09-01
- RentCafe — Average Rent in Surprise, AZ (updated August 31, 2026: 1BR $1,456, 2BR $1,762; city average $1,694) Market Data — Accessed 2026-09-06
- Surprise Municipal Code Chapter 26 Article X — Short-Term Rentals (Ord. No. 2023-13, 4-18-23) Municipal Code — Accessed 2026-09-06
- U.S. Census Bureau — Vintage 2024 Population Estimates, sub-est2024.csv (Surprise city, AZ: 167,564) Government Data — Accessed 2026-09-06
Frequently Asked Questions
Can I build an ADU in Surprise?
How much does an ADU cost in Surprise?
How much can I rent an ADU for in Surprise?
Do I need parking for an ADU in Surprise?
How long does it take to get an ADU permit in Surprise?
Ready to Build in Surprise?
Get free, no-obligation quotes from top-rated ADU contractors in Surprise.
Get Free Quotes →Build ADUs in Surprise?
Homeowners read this page while planning, then ask us to connect them with a local builder. We pass those requests to builders who cover Surprise — a flat fee only on the leads you accept, no subscription, and you contract directly with the homeowner.
See who's waiting in Arizona →