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SB1183 • 2026

accessory dwelling units; fire sprinklers

SB1183 - accessory dwelling units; fire sprinklers

Passed Legislature

This bill passed both chambers and reached final enrollment, even if later executive action is not shown here.

Sponsor
John Kavanagh, Lauren Kuby
Last action
2026-01-21
Official status
Senate second read
Effective date
Not listed

Plain English Breakdown

The official source material does not specify the exact impact of the bill on homeowners in cities with populations under 75,000 people. It only mentions that the section applies to municipalities with a population over seventy-five thousand persons.

Accessory Dwelling Units; Fire Sprinklers

This bill changes rules for accessory dwelling units in Arizona cities and towns, including requirements about fire sprinklers.

What This Bill Does

  • Allows cities to have at least one attached and one detached accessory dwelling unit on any lot where a single-family home is allowed.
  • Requires cities to allow an additional detached accessory dwelling unit if the lot is one acre or more in size and includes a restricted-affordable unit.
  • Limits the size of accessory dwelling units based on either 75% of the main house's floor area or up to 1,000 square feet.
  • Prohibits cities from setting rules that are stricter for accessory dwelling units than for single-family homes in the same zone.

Who It Names or Affects

  • Cities and towns with a population over 75,000 people
  • Homeowners who want to build accessory dwelling units on their property

Terms To Know

Accessory Dwelling Unit (ADU)
A self-contained living unit that is on the same lot or parcel as a single-family dwelling, includes its own sleeping and sanitation facilities, and may include kitchen facilities.
Restricted-Affordable Dwelling Unit
A dwelling unit rented to households earning up to 80% of the area median income through deed restrictions or development agreements with municipalities.

Limits and Unknowns

  • The bill does not apply to tribal land, military airport areas, and certain noisy public airports.
  • Cities that adopted a residential fire sprinkler ordinance before December 31, 2009 can require accessory dwelling units to have fire sprinklers.

Bill History

  1. 2026-01-21 Senate

    Senate second read

  2. 2026-01-20 Senate

    Senate Rules: None

  3. 2026-01-20 Senate

    Senate Government: None

  4. 2026-01-20 Senate

    Senate first read

Official Summary Text

SB1183 - accessory dwelling units; fire sprinklers

Current Bill Text

Read the full stored bill text
SB1183 - 572R - I Ver

REFERENCE TITLE:
accessory dwelling units; fire sprinklers

State of Arizona

Senate

Fifty-seventh Legislature

Second Regular Session

2026

SB 1183

Introduced by

Senators
Kavanagh: Kuby

AN
ACT

amending section 9-461.18, arizona
revised statutes; relating to accessory dwelling units.

(TEXT OF BILL BEGINS ON NEXT PAGE)

Be it enacted by the Legislature of the State of Arizona:

Section 1. Section 9-461.18, Arizona Revised
Statutes, is amended to read:

START_STATUTE
9-461.18.

Accessory dwelling units; regulation; applicability; definitions

A. A municipality shall adopt regulations that allow

all of the following
on any lot or parcel where a single-family
dwelling is allowed
all of the following
:

1. At least one attached and one detached accessory
dwelling unit as a permitted use.

2. A minimum of one additional detached accessory
dwelling unit as a permitted use on a lot or parcel that is one acre or more in
size if at least one accessory dwelling unit on the lot or parcel is a
restricted-affordable dwelling unit.

3. An accessory dwelling unit that is seventy-five
percent of the gross floor area of the single-family dwelling on the same lot
or parcel or one thousand square feet, whichever is less.

B. A municipality may not do any of the following:

1. Prohibit the use or advertisement of either the
single-family dwelling or any accessory dwelling unit located on the same lot
or parcel as separately leased long-term rental housing.

2. Require a familial, marital, employment or other
preexisting relationship between the owner or occupant of a single-family
dwelling and the occupant of an accessory dwelling unit located on the same lot
or parcel.

3. Require that a lot or parcel have additional
parking to accommodate an accessory dwelling unit or require payment of fees
instead of additional parking.

4. Require that an accessory dwelling unit match the
exterior design, roof pitch or finishing materials of the single-family
dwelling that is located on the same lot as the accessory dwelling unit.

5. Set restrictions for accessory dwelling units
that are more restrictive than those for single-family dwellings within
the same zoning area with regard to height, setbacks, lot size or coverage or
building frontage.

6. Set rear or side setbacks for accessory dwelling
units that are more than five feet from the property line.

7. Require improvements to public streets as a
condition of allowing an accessory dwelling unit, except as necessary to
reconstruct or repair a public street that is disturbed as a result of the
construction of the accessory dwelling unit.

8. Require a restrictive covenant concerning an
accessory dwelling unit on a lot or parcel zoned for residential use by a
single-family dwelling.

C. This section does not prohibit restrictive
covenants concerning accessory dwelling units entered into between private
parties. The municipality may not condition a permit, license or use
of an accessory dwelling unit on adopting or implementing a restrictive
covenant between private parties.

D. This section does not supersede applicable
building codes, fire codes or public health and safety regulations, except that
a municipality may not require an accessory dwelling unit to comply with a
commercial building code or contain a fire sprinkler
unless the
municipality adopted a residential fire sprinkler ordinance before DECEMBER 31,
2009
.
if the municipality adopted a
residential fire sprinkler ordinance before december 31, 2009, the municipality
may require an accessory dwelling unit to comply with that ordinance to the
same extent and in the same manner as another residential dwelling unit that is
subject to the same ordinance.�

E. An accessory dwelling unit may not be built on
top of a current or planned public utility easement unless the property owner
receives written consent from any utility that is currently using the public
utility easement or that may use the public utility easement in the future.

F. If a municipality fails to adopt development
regulations as required by this section on or before January 1, 2025, accessory
dwelling units shall be allowed on all lots or parcels zoned for residential
use in the municipality without limits.

G. This section does not apply to lots or parcels
that are located on:

1. Tribal land.

2. Land that is in the territory in the vicinity of
a military airport or ancillary military facility as defined in section 28-8461.

3. Land that is in the territory in the vicinity of
a federal aviation administration commercially licensed airport or a general
aviation airport or land that is in the territory in the vicinity of a public
airport as defined in section 28-8486 and that has a noise level of
greater than sixty-five decibels.

H. This section applies to a municipality with a
population of more than seventy-five thousand persons.

I. For the purposes of this section:

1. "Accessory dwelling unit" means a
self-contained living unit that is on the same lot or parcel as a single-family
dwelling of greater square footage than the accessory dwelling unit, that
includes its own sleeping and sanitation facilities and that may include its
own kitchen facilities.

2. "Gross floor area" means the interior
habitable area of a single-family dwelling or an accessory dwelling unit.

3. "Long-term rental" means rental
use in which the tenant holds a lease of ninety days or longer or on a
month-by-month basis.

4. "Municipality" means a city or town
that exercises zoning powers under this title.

5. "Permitted use" means the ability for a
development to be approved without requiring a public hearing, variance,
conditional use permit, special permit or special exception, other than a
discretionary zoning action to determine that a site plan conforms with
applicable zoning regulations.

6. "Restricted-affordable dwelling
unit" means a dwelling unit that, either through a deed restriction or a
development agreement with the municipality, is rented to households earning up
to eighty percent of
the
area median income.
END_STATUTE