8650 - AMENDING TITLE 9, “LAND USE CODE,”B.R.C. 1981, TO AMEND THE STANDARDS FOR ACCESSORY DWELLING UNITS; AND SETTING FORTH RELATED DETAILS Intro and 1st Rdg 1/9/25 and 2nd Rdg and Adopted 2/6/25K:\PLCU\o-8650 2nd Rdg-.docx
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ORDINANCE 8650
AN ORDINANCE AMENDING TITLE 9, “LAND USE CODE,”
B.R.C. 1981, TO AMEND THE STANDARDS FOR
ACCESSORY DWELLING UNITS; AND SETTING FORTH
RELATED DETAILS
BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF BOULDER,
COLORADO:
. . .
Section 1. The Accessory dwelling unit line under “Residential Uses” of Table 6-1: Use
Table in Section 9-6-1, “Schedule of Permitted Land Uses,” B.R.C. 1981, is amended to read as
follows:
9-6-1. - Schedule of Permitted Land Uses.
The schedule in Table 6-1 shows the uses that are permitted, conditionally permitted,
prohibited, or that may be permitted through use review.
. . .
TABLE 6-1: USE TABLE
A = Allowed | C = Conditional Use | U = Use Review | [ ] = Specific Use Standards Apply | - = Prohibited
Zoning District RR-1, RR-2,RL-2, RM-2RM-1,RM-3RMX-1 RMX-2 RH-1, RH-2,RH-3,RH-7RH-6 MH MU-3 MU-1 MU-2 MU-4 BT-1, BT-2BMS BC-1, BC-2BCS BR-1, BR-2DT-4 DT-5 DT-1, DT-2,IS-1, IS-2IG IM IMS P A Specific Use
Standards Use Module R1 R2 R3 R4 R5 R6 R7 R8 MH M1 M2 M3 M4 B1 B2 B3 B4 B5 D1 D2 D3 I1 I2 I3 I4 P A
RESIDENTIAL USES
Residential Accessory
Accessory dwelling unit [A] [A] -[A] [A] [A] -[A] -[A] - - -[A] -[A] -[A] -[A] -[A] - -[A] - -[A] -[A] -[A] -[A] - -[A] -[A] - [A] [A] 9-6-3(n)
. . .
Section 2. Section 9-6-3, “Specific Use Standards - Residential Uses,” B.R.C. 1981, is
amended to read as follows:
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9-6-3. - Specific Use Standards - Residential Uses.
(a) Residential Uses:
. . .
(n) Accessory Dwelling Unit:
(1) The following standards apply to an accessory dwelling unit:
(A) General Standards: An accessory dwelling unit shall meet the following
standards:
(i) Lot Limitations: An accessory dwelling unit may be created
established on a lot of 5,000 square feet or more with a one
detached dwelling unit. One accessory dwelling unit may be
located on a lot.
(ii) Maximum Floor Area: The accessory dwelling unit shall be limited
to the maximum floor area set forth in Table 6-3. The board of
zoning adjustment may grant a variance to this floor area
requirement pursuant to Section 9-2-3, “Variances and
Interpretations,” B.R.C. 1981.
Table 6-3: Maximum Floor Area
Accessory Dwelling Unit Affordable
Accessory
Dwelling Unit
Designated Historic
Property
Attached One-half of the total floor
area of the principal
structure or 1,000 square
feet, whichever is less,
except that if the
principal structure has
less than 1,500 square
feet of floor area, the
maximum is 750 square
feet.
Two-thirds of the total floor area of
the principal structure or 1,200 square
feet, whichever is less, except that if
the principal structure has less than
1,125 square feet of floor area, the
maximum is 750 square feet.
Detached 800 sq. ft. 1,000 sq. ft.
(iii) Off-Street Parking: The minimum number of off-street parking
spaces shall be provided on the lot or parcel as required by Table
6-4. The required parking spaces shall meet at least the minimum
dimensional requirements in Table 9-6, “Small Car Parking
Dimension Standards,” B.R.C. 1981, and may be located in a
required landscaped setback abutting the street.
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Table 6-4: Off-Street Parking Requirement
(iv) Owner-Occupied: The principal dwelling unit or accessory
dwelling unit on the parcel or lot must be owner-occupied. The
applicant shall provide evidence to the city manager to
demonstrate compliance with this requirement at the time of
application or any time thereafter. For entities that are similar to
ownership by a person, such evidence may include without
limitation declaration of trust ownership, articles of organization,
operating agreement, or similar documentation. The city manager
may approve a temporary absence of the owner-occupant for less
than one year with an affidavit of exemption pursuant to the
procedures for temporary rental license exemptions in Section 10-
3-2, “Rental License Required Before Occupancy and License
Exemptions,” B.R.C. 1981.
(iiiv) Rental License: No owner of the property shall allow, or offer to
allow through advertisement or otherwise, any person to occupy
the accessory dwelling unit or the principal dwelling unit as a
tenant or lessee or otherwise for a valuable consideration unless
such rented unit has been issued a valid rental license by the city
manager consistent with the requirements of Chapter 10-3, “Rental
Licenses,” B.R.C. 1981.
(ivi) Short-Term Rental: Short-term rental of an accessory dwelling unit
and short-term rental of a principal dwelling unit on a lot or parcel
with an accessory dwelling unit are prohibited except as
specifically authorized in Section 10-3-19, “Short-Term Rentals,”
B.R.C. 1981.
(vii) No Independent Conveyance: No person shall convey an accessory
dwelling unit independently of the principal dwelling unit on the
lot or parcel.
(viii) Declaration of Use Requiredfor Affordable Accessory Dwelling
Units: Before obtaining approval for an affordable accessory
dwelling unit, all owners shall sign a declaration of use, including
Accessory Dwelling Unit The number of off-street parking spaces
required in the zoning district for the
principal dwelling unit and one
additional off-street parking space
Affordable Accessory
Dwelling Unit
The parking required in the zoning
district for the principal dwelling unit.
Designated Historic
Property
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all the standards for continued use, to be recorded in the office of
the Boulder County Clerk and Recorder to serve as actual and
constructive notice of the legal status of the owner’s property. If
the unit is to be an affordable accessory dwelling unit, tThe
declaration shall include a sworn certification that the unit will
meet the affordability standard and a statement of the number of
bedrooms.
(vii) Prior Approvals: Any prohibition of accessory dwelling units in
any prior planned development, planned residential development,
planned unit development, site review, or use review approval is
void and shall not be enforced, provided the accessory dwelling
unit is established consistent with the requirements of this
subsection.
a. Review Process: The establishment of an accessory dwelling
unit on a property subject to a planned development, planned
residential development, planned unit development, or site
review shall be reviewed and approved under the minor
modification process and standards in Subsection 9-2-14(k)
and shall be deemed to not alter the basic intent of the site plan
approval under Subparagraph 9-2-14(k)(1)(B), provided the
proposal meets the remaining minor modification standards.
b. Use Review Exception: An accessory dwelling unit may be
established as an accessory use to a detached dwelling unit that
is subject to a use review approval without an amendment or
minor modification review under Section 9-2-15, “Use
Review,” B.R.C. 1981.
(viiiix) Amendments: The owner of an accessory dwelling unit may
amend the approved size, affordability status, or other
characteristics of an approved accessory dwelling unit by filing a
building permit application that demonstrates compliance with
applicable accessory dwelling unit standards. Prior to approval the
owner must sign an updated declaration of use to be recorded in
the office of the Boulder County Clerk and Recorder.
(2) Attached Accessory Dwelling Units: In addition to the general standards in
Paragraph (n)(1) of this section, the following standards apply to attached
accessory dwelling units.
(A) Interior Connections: All attached accessory dwelling units shall be
physically separated by a wall or a lockable door. If there is an interior
connection between the accessory dwelling unit and the principal dwelling
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prior to the creation of the accessory dwelling unit, the connection
together with the lockable, physical separation shall be maintained for the
duration of the accessory dwelling unit.
(B) Side Entrances: Any additional entrance resulting from the creation of an
attached accessory dwelling unit may face the side of the lot fronting on
the street only if such entrance is adequately and appropriately screened in
a manner that does not detract from the single-family appearance of the
principal dwelling unit.Rear Yard Setback: The minimum rear yard
setback for principal buildings established in Table 7-1 does not apply to a
principal building with an attached accessory dwelling unit provided the
following standards are met:
(i) Any floor area of the building located within the area of the
minimum rear yard setback established in Table 7-1 is solely floor
area of the accessory dwelling unit;
(ii) The attached accessory dwelling unit portion of the building has a
rear yard setback of five feet or more;
(iii) In the RR, RE, RL, and RMX-1 districts, the maximum building
coverage of the attached accessory dwelling unit portion of the
building and any accessory buildings or structures within the area
of the minimum rear yard setback established in Table 7-1 is 500
square feet; and
(iv) The maximum height of any portion of the building located within
the area of the minimum rear yard setback established in Table 7-1
is 20 feet. The height of this portion of the building shall be
measured to the uppermost point of the portion of the building with
the accessory dwelling unit consistent with Section 9-7-5,
“Building Height,” B.R.C. 1981.
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Figure 6-1: Maximum Height of Attached ADU in Rear Yard Setback
(3) Detached Accessory Dwelling Units: In addition to the general standards in
Paragraph (n)(1) of this section, the following standards apply to detached
accessory dwelling units:
(A) Maximum Height: The maximum height of accessory buildings with a
detached accessory dwelling unit shall not be greater than twenty feet. The
city manager may modify this height standard if the building meets one of
the following:
(i) If the roof pitch is 8:12 or greatersteeper, provided the building
height does not exceed 25 feet; or
(ii) If a legal existing accessory building is converted to a detached
accessory dwelling unit, provided that no changes are proposed to
the existing accessory building’s height, floor area, or roof form.
(B) Private Open Space: A detached accessory dwelling unit shall have a
minimum of sixty square feet of private open space provided for the
exclusive use of the occupants of the detached accessory dwelling unit.
Private open space may include porches, balconies, or patio areas.
. . .
Section 3. Footnote (f) to Table 7-1: Form and Bulk Standards in Section 9-7-1,
“Schedule of Form and Bulk Standards,” B.R.C. 1981, is amended to read as follows:
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9-7-1. - Schedule of Form and Bulk Standards.
. . .
Footnotes to Table 7-1, Form and Bulk Standards:
. . .
(f) Where a rear yard backs on a street, see Paragraph 9-7-2(c), B.R.C. 1981. For attached
accessory dwelling units, see Paragraph 9-6-3(n), B.R.C. 1981.
. . .
Section 4. Row four under “Use” of Table 9-2: Use Specific Motor Vehicle Parking
Requirements for Residential Uses in all Zones in Section 9-9-6, “Parking Standards,” B.R.C.
1981, are amended to read as follows:
9-9-6. - Parking Standards.
. . .
(b) Off-Street Parking Requirements: The number of required off-street motor vehicle
parking spaces shall beis provided in Tables 9-1, 9-2, 9-3, and 9-4 of this section; the
number of required off-street bicycle parking spaces shall beis provided in Table 9-8 of
this section:
. . .
(2) Use Specific Motor Vehicle Parking Requirements for Residential Uses:
TABLE 9-2: USE SPECIFIC MOTOR VEHICLE PARKING REQUIREMENTS FOR
RESIDENTIAL USES IN ALL ZONES
Use Parking Requirement
Rooming house, boarding house, fraternity,
sorority, group living, and hostels
2 spaces per 3 occupants
Efficiency living units, transitional housing 1 space per DU
Bed and breakfast 1 space per guest room + 1 space for operator or
owner's DU within building
Attached accessory dwelling unit, detached
accessory dwelling unit
0 The off-street parking requirement for the
principal DU must be met, plus any parking space
required for the accessory dwelling unit, see
Subsection 9-6-3(n), B.R.C. 1981
. . . . . .
. . .
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Section 5. If any section, paragraph, clause, or provision of this ordinance shall for any
reason be held to be invalid or unenforceable, such decision shall not affect any of the remaining
provisions of this Ordinance.
Section 6. This Ordinance is necessary to protect the public health, safety, and welfare of
the residents of the city and covers matters of local concern.
Section 7. The City Council deems it appropriate that this Ordinance be published by
title only and orders that copies of this Ordinance be made available in the office of the city clerk
for public inspection and acquisition.
INTRODUCED, READ ON FIRST READING, AND ORDERED PUBLISHED BY
TITLE ONLY this 9th day of January 2025.
______________________________
Aaron Brockett,
Mayor
Attest:
________________________________
Elesha Johnson,
City Clerk
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READ ON SECOND READING, PASSED AND ADOPTED this 6th day of February
_____________________________
Aaron Brockett,
Mayor
2025.
Attest:
_______________________________
Elesha Johnson,
City Clerk