03. TA250002 PZ Staff Report
Extracted text (via pymupdf)
22140 characters
TA250002
Page 1 of 12
Report to the Planning and Zoning Commission
Prepared by the Maricopa County Planning and Development Department
Case:
TA250002 – Accessory Dwelling Units / Short Term Rentals
Hearing Date:
November 6, 2025
Supervisor District:
All
Applicant:
Commission-Initiated
Request:
Text Amendment to amend the Maricopa County Zoning Ordinance
(MCZO) - to establish new standards for Accessory Dwelling Units (ADUs)
and Short-Term Rentals (STRs) consistent with recent mandates from the
Arizona Legislature and as prescribed in the Arizona Revised Statutes
(ARS) § 11-810.01.
EROP:
The item is not being processed through the standard EROP process. It is
being adopted as an emergency measure. As such there has not been a
public stakeholder meeting nor public meeting of the Planning and Zoning
Commission for discussion only. This is necessary to ensure the
amendments are adopted and effective before the first of the year in
accordance with state statutes.
Recommendation:
Initiate and Approve
Discussion:
Arizona Revised Statutes (ARS) were amended in 2024 directing counties to allow multiple accessory
dwelling units (ADUs) on parcels or lots where single-family dwellings are constructed. House Bill
2928 (HB2928) in ARS § 11-810.01 requires that owners of single-family dwellings be able to provide at
least one attached ADU and one detached ADU, with the option for a third ADU (second detached unit)
on a lot of at least one acre. Per the statute, counties may allow the third unit only as an affordable
dwelling unit available to households earning no more than 80% of the area median income (AMI).
Regulations must be in effect that allow an ADU of no greater than 75% of the size of the primary dwelling
or 1,000 square feet, whichever is less. Additional statutory restrictions prevent counties from creating
off-street parking requirements for the ADUs, or from creating restrictions on ADUs that are more
restrictive than those for the primary dwelling.
This amendment must be effective by December 31, 2025 and allow multiple ADUs on all parcels or lots
where single-family dwellings are permitted. Following Commission recommendation this ordinance
amendment will be considered by the Board at a November 19, 2025 hearing. The proposed language
will ensure compliance with Statutory mandates while setting reasonable limits on future ADUs.
The MCZO currently allows an accessory dwelling unit on any residential lot that contains a primary
dwelling unit. The ADU may either be attached or detached. It the ADU is attached to the primary dwelling
TA250002
Page 2 of 12
it is considered a portion of the primary building located within the lot’s building envelope (BE) meeting
the minimum setback lines from the front/street, rear and side property lines.
The County currently has no size limit for an ADU, apart from the respective zoning district’s development
standards (maximum yard coverages, maximum lot coverage, maximum building height, minimum
building setbacks noting allowances for detached structures to have limited encroachment inside
setbacks). Detached accessory buildings, including ADUs, may encroach partially or entirely in the
required rear and/or side yards. Encroaching accessory buildings may not cover (aggregate area under
roof) more than 30% of the required rear or side yard and must be set back at least 3’ from rear and side
lot lines. Detached accessory buildings are prohibited from a required front yard. All buildings, including
ADUs, may observe a maximum height of 30’ in Rural and Single-Family Residential zoning districts,. See
the illustration below:
Summary of proposed changes:
The proposed ordinance amendment changes standards in the Rural and Residential zoning districts and
clarifies new definitions consistent with the statutory provisions of HB 2928. The amendment
establishes new limits on ADUs. At least one attached ADU and one detached ADU would be permitted
on any lot where a single-family dwelling is permitted. On any parcel of at least one acre, a third ADU
(second detached unit) is also permitted but only if deed-restricted as an affordable unit.
The amendment will continue to require an attached ADU to be considered part of the principal building
and thus it must be located entirely within the building envelope. If a detached ADU is constructed so
that it encroaches wholly or partially within a required side and/or rear yard, it will continue to be subject
to the 30% maximum coverage within the yard area. However, the current allowance for a detached ADU
to meet a minimum 3’ setback will be changed to 5’ consistent with state statute. As an additional
measure beyond statutory requirements, if an ADU is constructed within the required yard, it will no longer
be allowed at the respective zoning district’s maximum building height but rather will be limited to a
maximum 18’ building height.
Current - MCZO ADU Standards (Attached or Detached)
TA250002
Page 3 of 12
New language also prevents more than one short-term rental on any lot or parcel with a single-family
dwelling and ADU/ADUs. The ordinance does not currently address short-term rentals (STR) as an
identified land use. A new definition has been added and the proposed language will place restrictions
on STRs in unincorporated Maricopa County.
The following illustrations (next page) are a summary of the changes proposed with this amendment.
TA250002
Page 4 of 12
PROPOSED AMENDMENT - MCZO ADU Standards
TA250002
Page 5 of 12
Proposed MCZO Amendments:
Staff proposes the following MCZO text amendment for emergency adoption. Proposed language is
in legislative edit format (added language underlined, deleted language crossed out) :
SECTION 201. DEFINITIONS
For the purpose of this Ordinance, certain words are hereby defined:
ACCESSORY DWELLING UNIT:
A habitable space either attached to or detached from an existing principal single-family
dwelling of greater square footage than the accessory dwelling unit on a property sharing
driveway access with the principal single-family dwelling.
DWELLING UNIT, ACCESSORY:
A habitable space either within or added to an existing primary dwelling unit, or within a separate
structure on the same lot as the primary dwelling unit used to house family or guests of the
occupants of the primary dwelling unit without compensation.
SHORT TERM RENTAL:
A single-family dwelling or an accessory dwelling leased, without signage, for a duration of 30
consecutive days or fewer to individuals other than registered sex offenders.
SECTION 501.
RURAL-190 (Rural Zoning District – 190,000 Square Feet Per Dwelling Unit)
ARTICLE 501.2.
USE REGULATIONS: A building or premises shall be used only for the
following purposes:
1.
One single-family dwelling per lot of record. Includes short term
rentals subject to Section 1208:
14.
Accessory dwelling unit (ADU)/guest house.
a.
Only one ADU/guest house shall be permitted where at least
one, but no more than one, single family residence exists on
the property
b.
An ADU/guest house may not be rented or leased separate
from the primary structure.
c.
An ADU/guest house shall not have a separate address or
mailbox from the principal dwelling.
TA250002
Page 6 of 12
14. Accessory dwelling unit: In accordance with Arizona State Statute,
ADUs are a permitted uses on any lot or parcel zoned for single-family
residential use. A public hearing, variance, or special permit shall not
be required.
a.
Number of Units.
1.
At least one attached and one detached ADU shall be
permitted on each lot or parcel where a single-family
dwelling is allowed.
2.
On lot or parcel one acre or larger, at least one additional
detached ADU shall be permitted provided that at least
one ADU on the lot be a deed restricted-affordable
dwelling unit to be rented to households earning up to
eighty percent of the area median income.
b.
Size.
1.
No ADU shall exceed the size of the principal dwelling.
2.
On lot or parcel less than one acre, the size of the ADU
shall be a maximum of 75% of the primary dwelling unit or
1,000 square feet whichever is less.
c.
Occupancy and Tenancy.
1.
ADUs may be leased or occupied independently of the
principal dwelling as long-term rental housing.
2.
No familial, marital, or employment relationship is required
between occupants of the principal dwelling and the ADU.
d.
Design Standards. ADUs shall be subject to the same height, lot
coverage, and frontage standards as single-family dwellings
within the zoning district. Except that:
1.
Detached ADUs may be built in the required rear yard
and/or the required side yard but shall not occupy more
than 30% of any required yard and shall not be nearer than
five feet to any side or rear lot line.
2.
Detached ADUs that encroach into the required side or
rear yard shall be limited to a height of 18 feet.
TA250002
Page 7 of 12
3.
All ADUs shall share a single access point to the street
with the primary residence; internal driveways may diverge
from this point.
e.
Any ADU lawfully established prior to adoption of this Article
that does not meet current standards may be continued as a
legal nonconforming use. Alterations or expansions must
comply with this Article.
f.
No more than one ADU may be used as a short-term rental.
SECTION 602.
R1-35 (Single-Family Residential Zoning District-35,000 Square Feet per
Dwelling Unit)
ARTICLE 601.2
USE REGULATIONS: A building or premises shall be used only for the
following purposes:
1.
One single-family dwelling per lot of record. Includes short term
rentals subject to Section 1208:
10.
Accessory dwelling unit (ADU)/guest house.
a.
Only one ADU/guest house shall be permitted where at least
one, but no more than one, single-family residence exists on
the property.
b.
An ADU/guest house may not be rented or leased separate
from the primary structure.
c.
An ADU/guest house shall not have a separate address or
mailbox from the principal dwelling.
10.
Accessory dwelling unit: In accordance with Arizona State Statute,
ADUs are a permitted uses on any lot or parcel zoned for single-family
residential use. A public hearing, variance, or special permit shall not
be required.
a.
Number of Units.
1.
At least one attached and one detached ADU shall be
permitted on each lot or parcel where a single-family
dwelling is allowed.
2.
On lot or parcel one acre or larger, at least one additional
detached ADU shall be permitted provided that at least
one ADU on the lot be a deed restricted-affordable
dwelling unit to be rented to households earning up to
eighty percent of the area median income.
b.
Size.
TA250002
Page 8 of 12
1.
No ADU shall exceed the size of the principal dwelling.
2.
On lot or parcel less than one acre, the size of the ADU
shall be a maximum of 75% of the primary dwelling unit
or 1,000 square feet whichever is less.
c.
Occupancy and Tenancy.
1.
ADUs may be leased or occupied independently of the
principal dwelling as long-term rental housing.
2.
No familial, marital, or employment relationship is
required between occupants of the principal dwelling and
the ADU.
d.
Design Standards. ADUs shall be subject to the same height,
lot coverage, and frontage standards as single-family
dwellings within the zoning district. Except that:
1.
Detached ADUs may be built in the required rear yard
and/or the required side yard but shall not occupy more
than 30% of any required yard and shall not be nearer than
five feet to any side or rear lot line.
2.
Detached ADUs that encroach into the required side or
rear yard shall be limited to a height of 18 feet.
3.
All ADUs shall share a single access point to the street
with the primary residence; internal driveways may
diverge from this point.
e.
Any ADU lawfully established prior to adoption of this Article
that does not meet current standards may be continued as a
legal nonconforming use. Alterations or expansions must
comply with this Article.
f.
No more than one ADU may be used as a short-term rental.
SECTION 1106 ACCESSORY BUILDINGS AND USES
ARTICLE 1106.1. CONSTRUCTION AND USE: Timing and Construction: An Aaccessory
buildings or uses shall not be constructed or established on a lot until construction of the
principal building or primary use has been actually commenced or the primary use established.
Accessory buildings shall not be used for dwelling purposes, except if specifically approved in a
Residential Unit Plan of Development, pursuant to the provisions of Chapter 10, Section 1002.,
Article 1002.9, if approved as an accessory dwelling unit/guest house, pursuant to the provisions
TA250002
Page 9 of 12
of Chapter 5, Section 501.2.14, or Chapter 6, Section 601.2.10, if approved for occupancy by
caretakers employed on the premises or if occupied pursuant to a Temporary Use Permit.
SECTION 1208. SHORT TERM RENTALS (STRs)
ARTICLE 1208.1. STANDARDS:
1208.1.1
A Short-Term Rental (STR) is the use of a single-family dwelling or an approved
accessory dwelling unit for lease or rent for a duration of no more than 30
consecutive days.
1208.1.2
In accordance with State Statute, the owner of a short-term rental must reside on
the property if the property contains an accessory dwelling unit unless a certificate
of occupancy, certificate of completion or similar final approval for the accessory
dwelling unit was issued by the County on or before September 13, 2024.
1208.1.2
The STR must be rented as a whole unit to a single party or individual. Partial
rentals (e.g., by the room or by the bed) are prohibited.
1208.1.3
Only one (1) STR unit may be rented per parcel at any given time.
1208.1.4
The following are prohibited in connection with any STR:
1.
Use of the property for commercial events, public assembly, or
special gatherings, including
2.
weddings, banquets, or similar functions.
3.
Signage, site-specific websites, or any external identification
suggesting commercial operation.
4.
Operation of any retail, food service, or other commercial enterprise
from the STR.
1208.1.5
The STR may not be rented, leased, or occupied by any person who is a registered
sex offender, and the lessee may not include such individuals as a member of the
renting party.
Conclusion:
The purpose of this text amendment is to ensure the MCZO is in alignment with State Statutes with the
primary goal of improving the availability and affordability of housing. This item was recommended by
the Chairman’s Task Force for the MCZO overhaul effort (ref.: TA250001) that occurred during the
summer months. If the overhaul occurs, language will include the changes that are being considered by
this amendment. Ultimately, this amendment is a lessening of regulatory burden by clarifying that both
ADUs and STRs are permitted uses.
TA250002
Page 10 of 12
TA250002 is an emergency measure and not being processed through the County’s Enhanced Regulatory
Outreach Program (EROP). It is being considered at the October 23, 2025 Planning and Zoning
Commission hearing for recommendation to the Board of Supervisors at the November 19, 2025 hearing
for adoption and to take effect 30 days or on December 19, 2025.
Recommendation:
1.
Staff recommends the Commission motion to initiate TA250002 and recommend it for Approval
as presented.
Presented by:
Ron Quarles, Senior Planner
Reviewed by:
Rachel Applegate, Planning Supervisor
Attachments:
Arizona Revised Statutes (ARS) § 11-810.01. (2 pages)
TA250002
Page 11 of 12
11-810.01. Accessory
dwelling
units;
regulation;
applicability;
definitions
A. A county shall adopt regulations that allow both of the following on any
lot or parcel where a single-family dwelling is allowed:
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. The county may require at
least one accessory dwelling unit on the lot or parcel to be a restricted-affordable
dwelling unit.
B. A county shall allow each accessory dwelling unit developed pursuant to
this section to be at least 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. This subsection does not prohibit a county from allowing an accessory
dwelling unit that is larger than the size of an accessory dwelling unit that is
allowed pursuant to this subsection.
C. A county 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. Except as provided in subsection A, paragraph 2 of this section, require a
restrictive covenant concerning an accessory dwelling unit on a lot or parcel zoned
for residential use by a single-family dwelling.
D. This section does not prohibit restrictive covenants or shared well
agreements as provided by state law concerning accessory dwelling units entered into
between private parties. The county may not condition a permit or license or the use
of an accessory dwelling unit on adopting or implementing a restrictive covenant
between private parties.
E. This section does not supersede applicable building codes, fire codes,
sensitive environmental area regulations, wildfire prevention regulations, emergency
vehicle access regulations, drainage and flood control regulations or public health
and safety regulations, except that a county may not require an accessory dwelling
unit to comply with a commercial building code or contain a fire sprinkler.
F. 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.
G. If a county fails to adopt development regulations as required by this
section on or before January 1, 2026, accessory dwelling units shall be allowed on
all lots or parcels zoned for residential use in the county without limits.
H. This section does not apply to lots or parcels that are located on:
1. Tribal land.
TA250002
Page 12 of 12
2. Land that is in the territory in the vicinity of a military airport or
ancillary military facility or property that is in a high noise or accident potential
zone 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.
I. If a new accessory dwelling unit will not be connected to a sewer system or
if the sewer system lacks capacity to serve the new accessory dwelling unit, a county
may require that any septic system that will be used to serve the accessory dwelling
unit be adequately sized before the construction of the accessory dwelling unit.
J. 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. "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.
5. "Restricted-affordable dwelling unit" means a dwelling unit that, either
through a deed restriction or a development agreement with the county, is rented to
households earning up to eighty percent of the area median income.