accessory dwelling units; requirements

HB4028 - 572R - I Ver

REFERENCE TITLE:
accessory dwelling units; requirements

State of Arizona

House of Representatives

Fifty-seventh Legislature

Second Regular Session

2026

HB 4028

Introduced by

Representative
Powell

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.

6.
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.

7.
Require
a restrictive covenant concerning an accessory dwelling unit on a lot or parcel
zoned for residential use by a single-family dwelling.

8. Require an administrative use
permit for constructing an accessory dwelling unit.

9. Require that the accessory
dwelling unit be located entirely within the space where buildings are allowed
as defined by applicable setbacks.

10. Require that an accessory
dwelling unit's building elevation meet applicable municipal elevation
criteria.

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.

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

2027
, 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