HomeMy WebLinkAboutPlanning 2017-10-26 ITEM 4 - ACCESSORY DWELLING UNIT REGULATION - STAFF REPORTCity of Tukwila
Department of Community Development - Jack Pace, Director
Allan Ekberg, Mayor
STAFF REPORT TO THE PLANNING COMMISSION
PREPARED OCTOBER 18, 2017
FILE NUMBERS: L17-0067 ADU Code Amendments
REQUEST: Review and revise Tukwila's accessory dwelling unit (ADU) regulations, hold a
public hearing and make a recommendation to the City Council.
LOCATION: City wide
PUBLIC NOTICE:
Hearing notice was published in the Seattle Times 10/12/17. A postcard was
mailed to the owners and tenants of LDR Zoned parcels. An email was sent to
the interested parties list.
STAFF: Nora Gierloff, Deputy DCD Director
ATTACHMENTS:
A. Revising city regulations to encourage accessory dwelling units — MRSC
Homelessness and housing toolkit for cities
B. Comparison of City ADU Standards
C. ADU Survey Responses
D. Detached ADU Examples
BACKGROUND
In March the City Council held a Housing Policy Work Session and considered a variety of housing
related actions. One of the items that the Council prioritized for policy consideration was an update to
Accessory Dwelling Unit (ADU) zoning standards to be followed by an amnesty program for existing
units. The intention was to create additional housing options and address the life safety issues in the
many illegal ADU conversions in the City.
Tukwila's current standards for ADUs are:
• Minimum lot size of 7,200 square feet (larger than the Low Density Residential standard of
6,500),
• The ADU is no more than 33% of the square footage of the primary residence and a maximum
of 1,000 square feet, whichever is less,
• One of the residences is the primary residence of a person who owns at least 50% of the
property,
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• The unit is incorporated into the primary single-family residence, not a separate unit, so that
both units appear to be of the same design as if constructed at the same time,
• Minimum of three parking spaces on the property with an ADU less than 600 square feet, and a
minimum of four parking spaces for an ADU over 600 square feet, and
• The ADU is not sold as a condominium.
Seattle's experience with loosening restrictions on ADUs and Portland's dramatic increase in the
number of ADUs built over the past few years have spurred a policy debate about this housing type. An
MRSC article about revising city regulations to encourage accessory dwelling units from its
Homelessness and Housing Toolkit is included as Attachment A. A table comparing Tukwila's current
ADU standards to neighboring jurisdictions as well as Portland is included as Attachment B.
DISCUSSION
Staff began public outreach and education about this issue in mid-July by developing a survey about
possible changes to current ADU standards. The intent was to give the Council a general sense of the
public support for or opposition to the possible changes. The survey was publicized at "See You in the
Park" events, emailed to Tukwila boards and commissions, emailed to 468 single family and duplex
landlords with rental housing licenses, published in the July Tukwila Reporter and posted on the City's
Facebook account.
We received 165 responses to the survey, see the results in Attachment C. Overall a majority supported
making changes to all of Tukwila's current standards, though for some questions such as maintaining the
owner occupancy requirement there was less than a 10% spread.
Staff took the survey results and policy options to the Community Development and Neighborhoods
Committee and City Council. Below is a discussion of key policy recommendations aimed at allowing
more flexibility for ADUs while trying to retain neighborhood protections.
Policy Recommendations
1. Begin allowing detached ADUs
Tukwila is the only city in the area that does not allow detached ADUs. They provide greater
flexibility and a greater degree of privacy between owner and tenant. However, these units are
also more visible so there should be standards that make them compatible with and visually
subordinate to the main house. Attachment D shows examples of detached ADUs that would
meet the size limitations recommended below.
• Not allowed if there is an attached ADU on site (only 1 ADU per parcel)
• Unit may be up to 800 square feet (must still meet the existing standards for total building
footprints of 2,275 sf and maximum impervious area of 4,875 sf for a 6,500 sf lot)
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• Detached units must be set back at least as far from the street as the main house. This
would not apply to the second front of a through or corner lot, or where the unit is
incorporated into an existing structure such as a detached garage.
• Limit height to 20 feet, which is lower than the existing 30 -foot height limit in LDR and
would allow a 1 story building with a loft or attic space. Building height is calculated from
the mid -point of any elevation change across the footprint of the house to the mid -point of
the pitched roof.
Average Grade
Alternatives:
A. Retain current ban on detached ADUs, Or
B. Select different area or height standards
2. Increase the percentage of the house that can be occupied by an attached ADU
Many houses are laid out in a way that makes it difficult to meet the limitation that the ADU
occupy no more than 1/3 of the floor area of the house. Increasing this percentage could make
for more livable units in small houses while retaining the 1,000 square foot ADU cap for larger
houses.
• Allow attached ADUs to occupy up to 40% of the square footage of the primary residence or
1,000 square feet, whichever is less.
Alternatives:
A. Retain standard limiting attached ADUs to 33% of the house, Or
B. Select a different area standard
3. Reduce the lot area requirement from 7,200 square feet to 6,500 square feet
There are approximately 3,000 Low Density Residential (LDR) zoned parcels that meet the 6,500
square foot minimum lot area in that Zone. Of these there are 330 between 6,500 and 7,200
square feet that would be newly eligible for an ADU if the area requirement were reduced.
None of our neighboring cities limit ADUs to lots that are larger than the standard in their zone.
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• Reduce the lot area requirement from 7,200 square feet to the LDR minimum lot area of
6,500 square feet for both attached and detached ADUs
Alternatives:
A. Retain the 7,200 SF standard, Or
B. Select different standards for attached and detached ADUs
4. Retain the owner occupancy requirement
Owner occupancy is required by all of our neighboring jurisdictions and Tukwila could attract
more absentee landlords if we were the only one in the area without that requirement.
Enforcing the occupancy requirement has been a challenge even though we do require an
affidavit to be recorded on the property's title. If an owner were temporarily unable to live on
site due to a work assignment, illness, or extended travel they would need to keep one of the
units (house or ADU) vacant.
Alternative:
A. Remove owner occupancy requirement
5. Retain Parking Requirements
In residential zones houses and apartments with up to 3 bedrooms are required to provide 2
parking spaces, with 1 additional space for every 2 bedrooms. ADUs up to 600 SF (generally 1
bedroom) are required to have 1 additional space while units over 600 SF (generally 2
bedroom) are required to have 2 additional spaces.
Tukwila, like its surrounding cities, averages 1.8 cars per household. Many of Tukwila's
neighborhoods do not have on -street parking to accommodate additional vehicles. Of our
neighboring cities only SeaTac requires a second parking space for larger ADUs.
Alternatives:
A. Reduce the parking requirement to 1 space per ADU of any size, Or
B. Allow a waiver of the second space for ADUs over 600 SF if the ADU is located on a block
with on -street parking
6. Provide an amnesty period for registration of illegal ADUs
We periodically become aware of illegal ADUs through code enforcement complaints and the
rental housing licensing program. Often these units have significant life safety issues because
they have not been built to meet building and electrical codes. We would like to incentivize
property owners to register these units and bring them up to code for the safety of the tenants.
Providing some flexibility on standards such as height, area, and parking would allow more
units to qualify. However, retaining the owner occupancy requirement is likely to be a barrier
for some landlords.
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• For a period of 1 year from the date of adoption of the code updates existing ADUs that do
not meet the new code standards may request flexibility from the Director for the
following:
a. Exceeding the permitted height for a detached ADU
b. Exceeding the permitted area for an attached or detached ADU
c. Not providing a second parking space for an ADU over 600 sf in area
d. Roof pitch of less than 5:12
e. Location of the ADU on the lot.
• We would not offer flexibility on owner occupancy, providing at least 1 parking space per
ADU, or meeting the 6,500 SF minimum lot size.
Alternatives:
A. Do not offer an amnesty, enforce all code requirements as we become aware of illegal
ADUs, Or
B. Limit flexibility to more/fewer standards
7. Do not create a residential occupancy limit in the Zoning Code
Seattle and SeaTac limit the number of residents per ADU. Tukwila's Zoning Code does not
currently define what constitutes a family or limit the number of individuals who may live
together in a dwelling. These types of regulations were removed from Tukwila's code because
they can be challenged under the Fair Housing Act as discriminatory, especially against families
with children. The International Building Code (IBC) Table 1004.1.2 sets a residential occupancy
load of 200 square feet per person. This is based on life safety standards and therefore less
susceptible to challenge than standards such as two people per bedroom.
• Continue to enforce the IBC but do not create a Zoning Code standard for residential
occupancy.
Alternative:
A. Consult with the City Attorney about what other types of occupancy limitations are
legally enforceable
Request
Hold the public hearing on the proposed changes, review each proposed change, and choose a policy
option. Staff will return with an ordinance for the PC to approve and forward to the City Council.
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