06.22.22 HAB ADU updateClick to edit Master title style
Housing Advisory Board –June 2022
Adapted from the
June 5, 2018
City Council Public Hearing Presentation
Schedule (2017-2018)
1. PROJECT LAUNCH 2. DISCUSSION DRAFT 3. FORMAL HEARINGS
4. Ongoing Monitoring
and Enforcement
Feb. 1, 2019:
Implementation date
Background
What is an Accessory Dwelling Unit?
(in-law apartment or basement / garage apartments)
A separate and complete housekeeping unit (e.g., kitchen,
sleeping area, and bathrooms) attached or detached from the
primary residential unit on a single-family lot
•Accessory Dwelling Unit (ADU) –typically within a single-family
home
•Owner Accessory Unit (OAU) –typically attached to a single-family
home or located in an accessory building
Background
DETACHED OAU
ADU
Background
History
•1983 first ordinance adopted
•Amended in late 1980s, 1997, 1999
•Toolkit of Housing Options 1999 and
2014 identified potential amendments
•Study in 2012 (survey of owners, national best practices, identification
of barriers)
•2016 BVCP Community Survey (62% supported allowing accessory
units in some single-family neighborhoods)
•As of May 2018, 231 legal accessory units in the city (1/2 of 1% of
housing stock)
Where are ADUs/OAUs?
2017 ADU Survey
230 Surveys sent –70% response rate
•74% say supplemental income was the reason they created or retained the unit
•20% noticed a large property tax increase; 18% noticed a small increase; 63% did not notice an increase or could not remember
•Estimate of the annual household income of their tenants:
–35% estimated incomes of less than $40,000
–40% were between $40,000 to $80,000
–25% were more than $80,000
2017 ADU Survey
Affordable Rents
Area Median
Income
1-2 Bedroom
Affordable Rents
2017
60%$1,222 –$1,476
75%$1,528 –$1,834
80%$1,630 –$1,956
2012
60%$1,056 –$1,267
75%$1,320 –$1,584
80%$1,408 –$1,690
•Affordable rents also
increased 14% for 2-
BR and 10% for a 1-BR
•88% of ADUs
affordable to 75% AMI
How are ADUs/OAUs Used?
Average
Occupancy is
1.51 people
Accessory units have been discussed as one tool to address Boulder’s
housing challenges over the past decade or more to help provide “a
diversity of housing types and price ranges,” which is a core value of
the Boulder Valley Comprehensive Plan. The current regulations
regarding accessory units are intentionally restrictive and have resulted
in a relatively small number of legal accessory units (230 as of January
2018) being constructed since the first ordinance was adopted in 1983.
Why Statement
The city, with the community, will craft a proposal for incremental changes
to the relevant regulations addressing accessory units (i.e., Accessory
Dwelling Units (ADUs) and Owner’s Accessory Units (OAUs)) to simplify the
regulations and remove apparent barriers to the construction of this housing
type in ways that are compatible with neighborhoods.
The ADU Update project is intended to achieve the following:
•Provide additional flexibility to homeowners to stay in their homes by
allowing for options that may either create supplemental revenue sources
or allow for aging in place on the property.
•Increase workforce and long-term rental housing opportunities while
balancing potential impacts to existing neighborhoods.
Purpose Statement
What is NOT Proposed to Change
1.Building code requirements
2.Zoning code requirements
•setbacks
•height limits
3.Occupancy limits
4.Owner occupancy requirements
Options for Changes
Evaluation Criteria:
•Simplify the regulations
•Remove apparent barriers
•Balance potential neighborhood impacts
•Increase workforce and long-term rental housing
opportunities
•Provide additional flexibility to homeowners to
stay in their homes
12 Options
1.Parking. Remove the parking requirement
2.Saturation. Increase the saturation from 10 to 20 percent
3.Legal Nonconforming Structures (Saturation Rule) Remove legal non-conforming structures from
the saturation requirement.
4.Allowed Zones. Allow OAUs and ADUs in all the same zones, including RMX-2.
5.ADU and Interior OAU Sizes. Change the 1/3 size limit to 1/2 for principal dwellings.
6.Lot Size. Lower the minimum lot size to 5,000 sq. ft. for ADUs and OAUs in allowed zones.
7.Detached OAU Size. Increase the size limit for a detached OAU from 450 to 800 sq. ft.
8.Detached OAU Design. Remove the design requirements related to garage doors, roof pitches,
height, and expansion of building coverage.
9.Five-Year Requirement. Remove the 5-year minimum requirement for the primary home.
10.Accessory Unit Permit Renewal. Remove the accessory unit permit transfer system.
11.Short-Term Rentals. Prohibit short-term rentals for newly created accessory units.
12.Accessory Unit Occupancy Limit. Remove the 2-person occupancy limit for the accessory unit
and allow roomers in the principal dwelling.
1. Parking
Requires one additional off-street parking
space
Original Intent. Reduce the impact of additional cars parked in the
street (public right-of-way)
Recommendation. Remove the parking requirement
Analysis
-Average car ownership 1.1 per unit (average occupancy is
1.51)
-Occupancy limits remain
-Type of structure does not dictate car ownership patterns
•Not require the one
additional parking
space for an affordable
ADU, or if the property
is landmarked, or is a
contributing structure
in a historic district.
•Allow parking in the
front setback for all
types of ADUs.
•Remove the
requirement for paved
parking.
2.Saturation
No more than 10% of the homes within 300
feet may have an ADU.
Original Intent. Prevent overabundance non-single-family
units in predominantly single-family neighborhoods
Recommendation.Increase the saturation rate from 10 to 20%
citywide
•Increase the saturation
rate from 10 to 20%
citywide. Allow up to
30% if the property is
landmarked or is a
contributing structure in
a historic district.
•Include co-ops when
calculating the
saturation rate.
•Saturation calculation –
only within the RL
zones.
2. Saturation
Zoning Number of
Parcels
RE 1,463
RL-1 10,643
RL-2 4,444
RR-1 123
RR-2 249
RMX-1 1,725
RMX-2 844
Total 19,501
Zoning Number of
Parcels
Parcels NOT
Eligible
RE 1,463 211
RL-1 10,643 3,020
RL-2 4,444 2,006
RR-1 123 6
RR-2 249 40
RMX-1 1,725 1,389
RMX-2 844 345
Total 19,501 7,017
Zoning Number of
Parcels
Parcels NOT
Eligible
Existing ADUs/
OAUs
RE 1,463 211 23 1.8%
RL-1 10,643 3,020 138 1.8%
RL-2 4,444 2,006 16 0.7%
RR-1 123 6 1 0.9%
RR-2 249 40 4 1.9%
RMX-1 1,725 1,389 49 15%
RMX-2 844 345 -
Total 19,501 7,017 231
% of eligible units 1.9%
% of all city housing units 0.5%
Zoning Number of
Parcels
Parcels NOT
Eligible
Existing ADUs/
OAUs
What if 5%
get Built
RE 1,463 211 23 1.8%61
RL-1 10,643 3,020 138 1.8%374
RL-2 4,444 2,006 16 0.7%121
RR-1 123 6 1 0.9%6
RR-2 249 40 4 1.9%10
RMX-1 1,725 1,389 49 15%14
RMX-2 844 345 -25
Total 19,501 7,017 231 612
% of eligible units 1.9%5.0%
% of all city housing units 0.5%1.3%
2. Saturation
2. Saturation
2. Saturation
2. Saturation
2. Saturation
3. Nonconforming Structures
Legal, nonconforming structures are included in
calculating the 10% saturation limit for ADUs
Original Intent. Prevent an overabundance of non-single-family
units in predominantly single-family neighborhoods
Recommendation. Remove non-conforming structures from the
saturation requirement
Analysis
-~500 properties are nonconforming, majority in the RL-1
zone
-Majority in Mapleton, Uni Hill and area between
-Allows the creation of an online tool to determine eligibility
No Change
4. Allowed Zones
OAUs are not allowed in the RL zoning districts
Original Intent. Prevent potential impacts of detached OAUs
(e.g., noise, privacy, solar access)
Recommendation. Allow OAUs and ADUs in all the
same zones, including RMX-2
Analysis
-OAUs currently not subject to the saturation rule
-Does not allow more accessory units (other than
RMX-2), just a different type
-Design issues addressed by compatible development
standards
-Allows creating distinction between OAUs and ADUs
Where OAUs are Currently Allowed
4. Allowed Zones
EXISTING PROPOSED
Zoning
Districts
Currently ADUs
are Allowed
(saturation limit
applies)
Currently OAU’s
are Allowed
(saturation limit
DOES NOT apply)
Allow ADUs and
OAUs
Saturation Limit
Applies
RR-1 X X X
RR-2 X X X
RE X X X
RL-1 X X X
RL-2 X X X
A X X
P X X
RMX-1 X X
RMX-2 X
Simplify Terminology
DETACHED ADUATTACHED ADU
5. ADU and Interior OAU Sizes
Size of ADU or an interior OAU limited to 1,000
sq. ft. or 1/3 the principal dwelling unit
(whichever is less)
Original Intent. Ensure that the accessory unit is smaller in size
and therefore subordinate to the main home
Recommendation. Change the 1/3 size limit to 1/2
Analysis
•Average ADU Size = 708 sq. ft.
•Primarily affects homes less than 2,000 sq. ft.
•Requires walling off portions of a basement
•Other subordination requirements remain (main entrance
screening)
•Allow Affordable
Attached ADUs
to be 1/2 the size
of the principal
dwelling or 1,000
sq. ft., whichever
is less.
•Market rate
Attached ADUs –
no change
6. Lot Size for ADUs and OAUs
A lot must be 6,000 sq. ft. or more to construct an
ADU or an OAU
(In RE and RR, must be 30,000 and 15,000 respectively)
Original Intent. Smaller lots (considered substandard) may not be
appropriate to accommodate an additional complete housekeeping
unit
Recommendation. Lower minimum lot size to 5,000 sq. ft. in all
zones
Analysis
•No similar requirement for accessory structures for office or other
uses
•Provides relief to small number of people (475 lots eligible)
Lower the
minimum lot
size from 6,000
to 5,000 sq. ft.
for all types of
ADUs.
7. Detached OAU Size
Detached OAUs limited to 450 sq. ft. in size
(existing structures limited to 500 sq. ft. of building coverage)
Original Intent. Detached OAUs have potential for increased impacts
compared to ADUs (noise, privacy, and solar access)
Recommendation. Increase the size limit for a detached OAU to
800 sq. ft.
Analysis
•Requirement pre-dates compatible development standards
•800 is a common size in other cities
•Allow up to 800 sq. ft. for
affordable Detached
ADUs.
•Increase the size limit for
a Detached ADU from
450 to 550 sq. ft.
•Remove the 1/3
percentage limitation.
•Allow up to 1,000 sq. ft.
for a Detached ADU that
is landmarked or is a
contributing structure in
a historic district.
8. Detached OAU Design
Requires design elements for garage doors, roof
pitches and building coverage
Original Intent. Create accessory buildings that look like traditional
carriage houses in predominately older neighborhoods
Recommendation. Remove the design requirements related to
garage doors, roof pitches and building coverage
Analysis
•Requirements for setbacks, height, consistent architecture/materials
and open space remain
•Rely on compatible development standards
9. Five-Year Requirement
A home must be at least 5 years old to create
an ADU
Original Intent. Help existing property owners remain in their
homes, NOT for new homeowners
Recommendation. Remove the 5-year requirement
Analysis
•Lower cost to build at time of construction
•Some build a house with the ADU and wait to permit
•Owner occupancy requirement will continue
10. Accessory Unit Permit Renewal
An accessory unit permit cannot be renewed with someone on
the waiting list
Original Intent. Provide fairness for property owners limited by the saturation rule in
obtaining an accessory unit permit when a property changes hands
Recommendation. Remove permit system and rely entirely on rental licensing and
building permitting to address life safety issues
Analysis
•Permit system renewal is duplicative of rental licensing program
•Once an accessory unit is created, only the owner can decide to remove it
•Wait list remains
•Remove the accessory
unit permit transfer
system.
•Continue to require a
declaration of use and
add specific language
for Affordable ADUs
that clearly states the
rent restriction
provisions and the
penalties for not
renting at or below the
limits.
11. Short-Term Rentals
Short-term rentals are allowed in either the accessory unit or
the principal dwelling
Original Intent. Short-term rentals are currently allowed
Recommendation.Prohibit short-term rentals for new accessory units
Analysis
•Owner occupancy requirement remains –owner expected to be responsible for the
behavior of their short-term renters
•Requires a rental license and are limited to renting only 120 days in a year
•Some owners depend on the income to finance the construction
•Counter to project purpose “…increase workforce and long-term rental housing
opportunities…”
•Existing short-term rental license holders can rent short-term for next 5 years
•Prohibit short-term rentals for
newly created ADUs.
•Allow owners with a current
ADU and a current short-term
rental license for the ADU (as of
Jan. 3, 2019) to continue renting
short-term until they either fail
to renew the permit or there is a
change of ownership.
•Owners that wish to create an
ADU must forfeit a short-term
rental license for the principal
dwelling.
12. Occupancy
Only two people are allowed to occupy an accessory unit
Original Intent. Ensure the number of people in the accessory unit is less than the
number of people living in the principal dwelling unit
Recommendation. Remove the 2-person occupancy limit for the accessory unit and
remove the prohibition on roomers in the principal dwelling
Analysis
•Allows additional flexibility for how people occupy the principal dwelling unit and the
accessory unit
•Retains the overall occupancy limit for the parcel of 3-4 unrelated people depending
on the zone
•Remove the 2-person
occupancy limit for
the ADU
•Allow roomers in the
principal dwelling
•Modify the current
occupancy limit for a
property with an
ADU to NOT include
the owner’s or
renter’s dependents
in the occupancy
count
Minor Code Amendments
•Amend when a rental license is required –
only if renting
•Remove the legal non-conforming use
provision
•Remove other code references related to
the 12 options
Sample Site Plan (RL-1)
•6,200 sq. ft. lot
•1,880 sq. ft. home
(1330+550)
•800 sq. ft. ADU
2-story
•60 sq. ft. of personal
OS for ADU
•Only 500 sq. ft. of
building coverage
allowed within the
rear yard setback
Compatible Development Standards (fall 2010)
Four combined requirements to achieve a more compatible built environment with
fewer negative impacts on neighboring properties:
1.Side Yard Bulk Plan (9-7-6) –ensure that buildings step down towards neighboring
properties in order to enhance privacy, preserve some views, and allow visual
access to the sky for lots adjacent to new development.
2.Side Yard Wall Articulation (9-7-10) –reduce the perceived mass of a building by
dividing it into smaller components, or to step down (decrease) the wall height
3.Maximum Building Coverage (9-7-11) –establish the maximum percentage of lot
surface that may be covered by principal and accessory buildings to preserve open
space on the lot, and to preserve some views and visual access to the sky, and
enhance privacy for residences that are adjacent to new development.
4.Floor-Area -Ratio Requirements (9-8-2) –address the proportionality of building
size to lot size and allow variation in building form within the established building
envelope.
12 Options
1.Parking. Remove the parking requirement
2.Saturation. Increase the saturation from 10 to 20 percent
3.Legal Nonconforming Structures (Saturation Rule) Remove legal non-conforming structures from
the saturation requirement.
4.Allowed Zones. Allow OAUs and ADUs in all the same zones, including RMX-2.
5.ADU and Interior OAU Sizes. Change the 1/3 size limit to 1/2 for principal dwellings.
6.Lot Size. Lower the minimum lot size to 5,000 sq. ft. for ADUs and OAUs in allowed zones.
7.Detached OAU Size. Increase the size limit for a detached OAU from 450 to 800 sq. ft.
8.Detached OAU Design. Remove the design requirements related to garage doors, roof pitches,
height, and expansion of building coverage.
9.Five-Year Requirement. Remove the 5-year minimum requirement for the primary home.
10.Accessory Unit Permit Renewal. Remove the accessory unit permit transfer system.
11.Short-Term Rentals. Prohibit short-term rentals for newly created accessory units.
12.Accessory Unit Occupancy Limit. Remove the 2-person occupancy limit for the accessory unit
and allow roomers in the principal dwelling.
Other Cities
•Santa Cruz
–Established fee waiver program for deed restriction (little activity)
•$14K waiver for 50% AMI
–New pilot with Habitat for Humanity -limited to seniors (3 to date)
•$80K loan from city (3%)
•$80K loan from habitat (0%)
•$50K loan for volunteer labor (0% / forgivable)
•Rents restricted for life of loan at 60% AMI
•Denver
–Creating a West Denver Pilot with Habitat for Humanity (west of I-25 near Colfax)
•Developing pre-approved prototype designs
•$25K loan from city’s housing fund (0%)
•$203K loan from Fannie Mae
•Rents restricted for 20-30 years at 80% AMI
•Durango
–Entire Code Rewrite
•Pre-register of illegal units –fees to legalize depend on date established (1989) –no inspection, owner signs affidavit
•Will allow in all residential zones this year (owner occupancy, no short-term rentals, 550 sq. ft. limit, no variances)
ADU Permitting and Reforms in Portland, OR
Nonconforming Structures
RMX-2 Zoning
Nonconforming Structures
ESTIMATED ADU/OAU FEES
•Application fee:$420
•Transfer of an existing permit fee: $168
•Rental Licensing application fee: $105
•Building, electric, mechanical fee, plumbing
fees: range $400 -$1,000s
ADU / OAU STATS
ADUs
•174 Legal Units
–Median Lot Size = 9,496 sq. ft.
–Average ADU Size = 708 sq. ft.
OAUs
•55 Legal Units (40 Detached / 15 Attached)
–Median Lot Size = 7,185 sq. ft.
–Detached Average OAU Size = 712 sq. ft.
–Attached Average OAU Size = 467 sq. ft.