1. The question, as people ask it
"Can someone build a fourplex next door to me anywhere in Phoenix now?" — also asked as "Did Phoenix legalize fiveplexes?", "Is my lot in the Phoenix Middle Housing Overlay District?", and "Are historic districts exempt from Phoenix middle housing?"
2. The short answer
No. The overlay covers a mapped area within one mile of Downtown, plus new subdivisions that opt in. It does not cover the rest of the city.
- On November 19, 2025, the Phoenix City Council adopted a text amendment creating the Middle Housing (MH) Overlay District, Zoning Ordinance § 632 (case Z-TA-1-25-Y, Ordinance G-7446), and a companion rezoning that mapped the overlay onto about 4,467 acres within one mile of the Downtown Code boundary (case Z-3-25-4-7-8, Ordinance G-7447).
- Inside the overlay, a lot may hold up to four primary dwelling units. Not five.
- Land in the vicinity of Phoenix Sky Harbor International Airport, south of Downtown, is excluded from the map.
- Outside the map, the only way onto the overlay is the opt-in route for new subdivisions of ten or more contiguous acres platted on or after January 1, 2026, and then only for up to 20% of the subdivision's lots.
- Historic districts inside the one-mile area are not exempt. A 2026 state bill that would have carved them out died in the Senate.
3. Why you may have heard otherwise
"Fiveplex." Some early summaries of the state law said it required fiveplexes. The statute lists "duplexes, triplexes, fourplexes and townhomes" (A.R.S. § 9-462.13(A)), and the Phoenix ordinance says "up to four primary dwelling units per lot" (ZO § 632.A.1). No five-unit building appears in either text.
"All of Phoenix." The state law applies to single-family lots "within one mile of the municipality's central business district" and to at least 20% of "any new development of more than ten contiguous acres" (§ 9-462.13(A)(1)–(2)). Phoenix implemented exactly those two paths: a mapped one-mile overlay and an opt-in for large new subdivisions. The city's own explainer states the amendment will not allow "Smaller lots than currently permitted by ordinance" or "More lots than currently permitted by ordinance."
"Historic districts got an exemption." HB 2375 (2026) would have added historic-district exclusions to § 9-462.13. It passed the House on March 18, 2026 and was never heard in the Senate; the Legislature's own record lists its final disposition as "Held in Senate." Its companion vehicles, SB 1118 and SB 1601, also died. In Phoenix, HP-zoned or HP-designated properties inside the overlay keep their Chapter 8 historic-preservation design review "with no modifications by this overlay district" (§ 632.E.6.a), but they are inside the overlay.
4. What the ordinance actually says
From the ordinance text adopted with Z-TA-1-25-Y (Exhibit A, August 29, 2025):
- Purpose: "entitle properties within the Middle Housing Overlay District to have up to four primary dwelling units per lot" (§ 632.A.1).
- Eligibility: properties rezoned with the overlay under Section 506, or lots in a subdivision "having a plat recorded on or after January 1, 2026" that is "contiguous and a minimum 10 gross acres in size," has never used the middle-housing provisions before, sits in one of the listed base districts (RE-43 through R-5, R-4A, C-1, C-2, C-3), is not near Sky Harbor, Deer Valley, or Scottsdale Airport, a military airport, or on tribal land, and whose owner has opted in (§ 632.C). The overlay lots may not exceed 20% of the subdivision's lots; a subdivision of fewer than five lots gets one (§ 632.C.2.e).
- Opt-in: the subdivision owner signs a notarized opt-in form and submits a legal description; staff process a zoning-map change (§ 632.D).
- Density: the greater of what the base zoning allows or four primary dwelling units per lot; the number of subdivided lots per acre does not change (§ 632.E.2).
- Setbacks and height: "the same as for a single-family dwelling unit on the same property" (§ 632.E.3).
- Lot coverage: same as the base district, except RE-43, RE-35, RE-24, and R1-14 lots may reach 50% when all structures are one story and no taller than 20 feet (§ 632.E.4).
- Parking: two spaces for a lot with one primary unit; one space per unit on lots with two or more (§ 632.E.5).
- The map: the companion rezoning covers "the area generally within one mile of the Downtown Code boundary," approximately 4,467.45 acres, in Council Districts 4, 7, and 8, with the Sky Harbor vicinity excepted (City Council report, agenda date 11/19/2025, item 72).
The state deadline was January 1, 2026: "middle housing shall be allowed on all lots in the municipality zoned for single-family residential use without any limitations" if a city missed it (§ 9-462.13(E)). Phoenix adopted before the deadline, so that citywide fallback did not trigger.
5. What's still unsettled
- The compiled-code check. Re-read September 4, 2026: the current compiled Phoenix Zoning Ordinance § 632 matches the adopted exhibit on every standard summarized here and identifies Ordinance G-7446, § 18 (2025). The code host says it is current through Ordinance G-7461, passed December 3, 2025; confirm later amendments with the City Clerk before relying on a specific standard.
- The vote record. News reports describe the November 19, 2025 approval as unanimous. We did not read the council minutes; the tally is not stated here as fact.
- The exact map. The one-mile boundary and the airport exception are drawn on the city's map exhibit. Whether a specific parcel is inside is a parcel-level question. Check the city's zoning map or the Planning and Development Department.
- Private covenants. § 9-462.13 does not say whether recorded CC&Rs that bar multi-unit buildings survive inside the overlay. Scottsdale's ordinance excludes CC&R-restricted lots; Phoenix's § 632 text we read does not address the point.
- Will a historic-district carve-out return in 2027? Unknown. As of this page's date no such bill exists to cite.
