HomeMy WebLinkAboutA036 - Third reading and adoption of ORD 4596 on ZTA for Accessory Dwelling Units (ADU)To:Mayor & City Council
From:Benjamin Campbell, Planner
Date:June 23, 2026
Subject:Zoning Text Amendment
Item No. 40
MEMO
The ordinance regarding proposed Zoning Text Amendment for Accessory
Dwelling Units (ADU) is attached for third reading and adoption.
ATTACHMENT(S):
DRAFT_Zoning_Text_Amendment_for_ADUs.pdf
Planning and Housing 515.239.5105 main
515.239.5142 fax
515 Clark Ave. P.O. Box 811
Ames, IA 50010
www.CityofAmes.org
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ORDINANCE NO. ____
AN ORDINANCE TO AMEND THE MUNICIPAL
CODE OF THE CITY OF AMES, IOWA, BY
AMENDING SECTIONS 29.409 AND 29.1502
THEREOF, FOR THE PURPOSE OF
AMENDING ACCESSORY DWELLING UNIT
(ADU) STANDARDS, REPEALING ANY AND
ALL ORDINANCES OR PARTS OF
ORDINANCES IN CONFLICT TO THE EXTENT
OF SUCH CONFLICT; AND ESTABLISHING
AN EFFECTIVE DATE.
BE IT ENACTED, by the City Council for the City of Ames, Iowa, that:
Section One. The Municipal Code of the City of Ames, Iowa shall be and
the same is hereby amended by amending Sections 29.409 and 29.1502 as
follows:
“Sec. 29.409. ACCESSORY DWELLING UNIT (ADU) STANDARDS.
An ADU is a newly constructed additional residential dwelling unit located on the
same lot as a single-family residence as defined by state law. This includes
properties with a single-family or two-family dwelling defined within the Zoning
Ordinance.
(1) Where Permitted.
(a) An ADU is permitted on any lot:
(i) with only a single-family residence. and
(ii) that is within a zoning district that allows for single-family
residence as a principal use.
* * *
(c) An ADU proposed for a lot within a local historic district or on a
locally designated property shall be regulated to the extent that the
City or Historic Preservation Commission determine that the
proposed ADU would be incongruous with the historical,
architectural, archaeological, or cultural aspects of the area, and
enters into official records the reasons for such determination.
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* * *
(3) Development Requirements.
* * *
(b) Setbacks.
(i) Where side setbacks are based on building height, the
single-family residence and the detached ADU shall
individually have minimum setbacks based on their
respective heights.
(ii) Setbacks for an attached ADU shall be the same as the
single-family residence to which it is attached.
* * *
(4) Size Limitations and Bedrooms.
(a) The ADU may must not exceed 1,000 square feet or 50% of the
size of the single-family residence, whichever is larger.
(i) Size means the gross living area of the primary dwelling unit
excluding garages, decks, and unheated porches. For
purposes of this section, size of the single-family residence
is calculated on the Gross Floor Area as defined in Sec.
29.201.
(ii) The size calculation of an accessory dwelling unit shall
exclude unfinished basements. It may therefore be
impermissible to finish and complete an unfinished
basement of an ADU if finishing this space causes the ADU
to exceed the size limitation set in Sec. 29.409(4)(a). For
purposes of this section, the size of the ADU is calculated on
the Gross Floor Area as defined in Sec. 29.201.
* * *
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Sec. 29.1502 Site Development Plan Review
* * *
(7) Alternative Design Review.
* * * (d) Ineligible Standards. The following standards in Chapter 29 of
the Municipal Code are not eligible:
* * *
(vii) Dwelling Design Standards of 29.409 and 29.410., with the
exception of ADU standards for side and rear setbacks and lot
coverage.
* * * ”
Section Two. All ordinances, or parts of ordinances, in conflict herewith
are hereby repealed to the extent of such conflict, if any.
Section Three. This ordinance shall be in full force and effect from and
after its passage and publication as required by law.
Passed this day of , .
_____________________________ ___________________________
John A. Haila, Mayor
First Reading:
Second Reading:
Third Reading:
Passed on:
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I, Renee Hall, City Clerk of the City of Ames, Iowa, hereby certify
that the above and foregoing is a true copy of Ordinance No. ______________,
passed by the City Council of said City at the meeting held on
______________________and signed by the Mayor on
___________________________, and published in the Ames Tribune on
___________________________.
________________________________
Renee Hall, City Clerk
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