HomeMy WebLinkAboutReg 2023-11-20 Item 4 - Presentation - Medium and High Density Zoning AnalysisCOUNCIL AGENDA SYNOPSIS
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ITEM INFORMATION
ITEM No.
4
STAFF SPONSOR: NEIL TABOR
ORIGINAL AGENDA DATE: 11/20/23
AGENDA ITEM TITLE Medium and High -Density Zoning Analysis
CATEGORY ❑ Discussion
Mtg Date 11/20/23
❑ Motion
Mfg Date
❑ Resolution
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❑ Ordinance
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SPONSOR ❑ Council ❑ Mayor ❑ Admin Svcs ® DCD ❑ Finance ❑ Fire ❑ P&R ❑ Police ❑ PW
SPONSOR'S
SUMMARY
This short presentation and attached report provide an analysis of Tukwila's medium and
high -density residential zoning district development regulations and the market for
residential development in Tukwila.
This item is intended for information only.
REVIEWED BY
❑ Trans&Infrastructure Svcs ❑ Community Svcs/Safety ❑ Finance & Governance ❑ Planning & Community Dev.
❑ LTAC
DATE:
❑ Arts Comm.
❑ Parks Comm. ❑ Planning Comm.
COMMITTEE CHAIR:
RECOMMENDATIONS:
SPONSOR/ADMIN. N/A, Information Only
COMMITTEE
COST IMPACT / FUND SOURCE
EXPENDITURE REQUIRED
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AMOUNT BUDGETED
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APPROPRIATION REQUIRED
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Fund Source:
Comments:
MTG. DATE
RECORD OF COUNCIL ACTION
MTG. DATE
ATTACHMENTS
11/20/23
Informational Memo, Medium and High -Density Zoning Analysis
Report on Medium and High -Density Zoning Analysis
Condensed Presentation on Medium and High -Density Zoning Analysis
1
2
City of Tukwila
Allan Ekberg, Mayor
INFORMATIONAL MEMORANDUM
TO: Tukwila City Council
FROM: Nora Gierloff, AICP, Community Development Director
BY: Neil Tabor, AICP, Senior Planner
CC: Mayor Ekberg
DATE: November 20, 2023
SUBJECT: Medium and High -Density Zoning Analysis
ISSUE
The report and short presentation attached provide an analysis of Tukwila's medium and high -
density residential zoning district development regulations and the market for residential
development in Tukwila.
BACKGROUND
As part of the comprehensive plan periodic update grant, staff entered into a contract with
MAKERS Architecture and Urban Design, with Leland Consulting Group providing expertise on
housing analysis as a subconsultant. Staff will provide context for the information and introduce
Jennifer Shuch, Analyst, and Chris Zahas, Managing Principal, from Leland Consulting Group,
who will present the material.
This presentation focuses primarily on the MDR and HDR zoning districts and provides a
summary of Leland's findings on how City regulations currently restrict housing development.
Recommendations are provided for regulations or processes the City could consider to enhance
the likelihood and viability of new residential development.
DISCUSSION
The presentation is intended for informational purposes only.
RECOMMENDATION
N/A
ATTACHMENTS
Medium and High -Density Zoning Analysis Report
Medium and High -Density Zoning Analysis Presentation
3
4
Medium- and High -Density Zoning Analysis
PREPARED FOR
City of Tukwila
SEPTEMBER 2023
PREPARED BY
L LELAND CONSULTING GROUP
01
0)
Purpose and Goals
Purpose
Leland Consulting Group, Inc. (LCG) was engaged by the City of Tukwila
as part of a multidisciplinary team led by MAKERS Architecture and Urban
Design LLP to evaluate and analyze the demand for medium- and high -
density residential and mixed -use development in Tukwila (MDR and HDR
zones), identify barriers to development, and suggest policies,
development code updates, or other changes to remove these barriers.
The balance of this memo includes analyses of Tukwila's zoning code
and related policies, local demand for medium- and high -density
multifamily, typical construction types in South King County, and
feasibility challenges in Tukwila.
Goals
The goal of this project is to assist the City of Tukwila in updating the
City's Comprehensive Plan for the 2024- 2044 planning horizon as
required by the Growth Management Act. The strategic advice
provided by LCG in this memo will support MAKERS and the City in
identifying gaps related to PSRC, GMA and the Countywide Planning
Policy requirements.
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
1
Executive Summary
Topic Findings
Zoning
The main zoning challenges impacting feasibility in Tukwila's MDR and HDR zones relate to density restrictions, height limits, maximum lot coverage
requirements, upper floor step -backs, required recreation space per unit, and parking. Similar requirements also present challenges in the RCC and
NCC zones. Separate standards for senior housing are also unnecessary. There may be an opportunity to extend the HDR zone along S 144th Street.
Multifamily Tax
Exemption (MFTE)
Tukwila was the only city in south King County that didn't have an MFTE program until a program was adopted very recently. This program helps
developers build new housing in areas where the rents are not always sufficient to offset rising construction and labor costs. The MFTE program will
help Tukwila compete for development with neighboring cities, but the City should consider expanding it beyond its current limited boundaries.
Processes Design review is required for all housing in the MDR and HDR zones, adding time and expense to relatively small development projects that could
instead be approved by administrative review.
Demand
There is relatively strong demand for medium- and high -density multifamily units in South King County, particularly in Tukwila. While in other cities
the vacancy rates for these building types are expected to increase slightly by 2028, the lack of building in Tukwila compared with other South King
County cities is likely to result in even tighter vacancy rates in the future.
Recent Development
There has been no recent development in the MDR or HDR zones in Tukwila, and two out of three developments in the pipeline have utilized
development or master -plan agreements to bypass local zoning. Recent developments in South King County have primarily included garden, urban
garden, and podium construction. These housing types are not feasible in MDR or HDR zones under Tukwila's current zoning code.
Novel Housing Types New middle housing types and point access blocks have been legalized in cities like Seattle and Portland. Tukwila should make sure that its zoning
and building codes allow for the construction of these types of housing.
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 2
v
CO
Table of Contents
Background & Existing Conditions
Current Zoning
Recent Housing Development in Tukwila
South King County Housing Market
Housing Market Dynamics
Common Multifamily Prototypes in South King County
New Typologies
Analysis
Feasibility Challenges
Aligning Zoning Code & Housing Goals
Opportunity Areas
Conclusions & Recommendations
Recommendations
3
4
9
14
15
22
27
33
34
39
43
45
46
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 3
Background & Existing Conditions
0
Current Zoning
• Tukwila's zoning code has three residential zones: Low Density Residential (LDR),
Medium Density Residential (MDR), and High Density Residential (HDR)
• The following slides summarize the regulations in the MDR and HDR zones,
pointing out which are most likely to have a negative impact on development
feasibility.
• In addition, this section includes a summary and key takeaways for Tukwila's
Residential Commercial (RCC) and Neighborhood Commercial (NCC) zones.
Loosening Restrictions in MDR and HDR Zones Will Improve
Feasibility and Provide Developers More Flexibility
The following pages include zoning and parking standards for developments
in MDR and HDR zones. Zoning criteria is highlighted based on their level of
impact to feasibility. The colors indicate:
Likely Feasibility Impact
Moderate Feasibility Impact
Significant Feasibility Impact
As discussed previously, the major impediments to housing production in
the MDR and HDR zones include:
• Density Restrictions: Current density restrictions (14.5 units per acre in
MDR zones and 22 units per acre in HDR zones) significantly limit what
can be built, impacting the feasibility of housing types typical in South
King County, especially when compounded by other restrictions.
• Maximum Lot Coverage & Lot Area Per Unit: The maximum lot
coverage is 50% in both MDR and HDR zones, but it is further reduced
by recreational space and vehicle circulation requirements. In many cases,
this reduces density beyond the already tight restrictions. Tukwila also
requires a high lot area per unit ratio, at 3,000 SF for MDR and 2,000 SF
for HDR. This requirement is not needed in conjunction with the already
low lot coverage ratio. It impacts feasibility by forcing developers to build
fewer, larger units.
• Upper Floor Step -Backs: While the setbacks required in MDR and HDR
zones are fairly typical (15-foot front setbacks, 10-foot side setbacks), the
additional step -backs required for upper floors significantly limit the
number of units that can be built. The townhome, garden, and podium -
style projects that typically get built in South King County have relatively
uniform facades. Requiring each floor to be set back an additional 10 feet
or more makes Tukwila a less appealing place to add new housing than
other nearby cities with fewer restrictions.
• Recreation Space (Non -Senior Housing): Tukwila requires 400 SF of
recreation space per unit in non -senior housing. This recreation space
then further limits the maximum lot coverage. Reducing the required
recreation space to 100 SF per unit, as is the case in Tukwila's senior
housing regulations, would help improve feasibility.
• Structured Parking in the URO: Tukwila's Urban Renewal Overlay
includes land zoned MDR and HDR. In this zone, 75% of required parking
for multifamily properties must be in a structure (either a garage or
podium). This is not feasible for projects at the densities required by
Tukwila's zoning. Even in larger garden and podium style projects in
South King County, much of the parking is in surface lots due to the rents
in the area and the high cost of providing structured parking (typically
$45,000 per space).
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 6
Zoning Summary
Minimum Lot Area
Lot Area per Unit
Maximum Density
Senior
Non -Senior
Setbacks
Front
Second Front
Sides
Rear
Stepbacks
Front (2nd Floor)
Front (3rd Floor)
Front (4th Floor)
Second Front (2nd Floor)
Second Front (3rd Floor)
Second Front (4th Floor)
Sides (2nd Floor)
Sides (3rd Floor)
Sides (4th Floor)
Medium Density
8,000 SF
3,000 SF
High Density
9,600 SF
2,000 SF1
14.5 60
14.5 22
15 feet
7.5 feet
10 feet
10 feet
15 feet
7.5 feet
10 feet
10 feet
20 feet 20 feet
30 feet 30 feet
(TH: 20 feet) (TH: 20 feet)
45 feet
(TH: 20 feet)
10 feet 10 feet
15 feet
15 feet (TH: 10 feet)
22.5 feet
(TH: 10 feet)
20 feet
(TH: 10 feet unless
(TH: 10 feet) adjacent to LDR)
20 feet
20 feet (TH: 10 feet unless
(TH: 10 feet unless adjacent adjacent to LDR; 30 feet
to LDR) if adjacent to LDR)
30 feet
(TH: 20 feet unless
adjacent to LDR)
Rear (2nd Floor)
Rear (3rd Floor)
Rear (4th Floor)
Townhome Building Separation
1-2 Story Buildings
3-4 Story Buildings
Maximum Height
Max Lot Coverage*
Multifamily
Townhomes
Recreation Space
Non -Senior
Senior
Maximum Building Length
General
Bonus for Modulating Off -Sets
2-Story Buildings
>2-Story Buildings
Townhomes
Medium Density High Density
20 feet 20 feet
(TH: 10 feet unless adjacent (TH: 10 feet unless
to LDR) adjacent to LDR)
20 feet 20 feet
(TH: 10 feet unless adjacent (TH: 10 feet unless
to LDR; 30 feet if adjacent adjacent to LDR; 30 feet
to LDR) if adjacent to LDR)
30 feet
(TH: 20 feet unless
adjacent to LDR)
10 feet
20 feet
30 feet'
50%
75%
400 SF/du
(1,000 SF minimum)
50 feet
100 feet
100 feet
80 feet
TH: Townhome-Specific Regulation
'Lot area per unit does not apply to senior housing
10 feet
20 feet
45 feet
50%
75%
400 SF/du
100 SF/du
50 feet
200 feet
200 feet
125 feet
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
7
Zoning Summary
Single Family
Multifamily
Typical
In URO (including Mixed Use)
Cars Bicycles
2 for each dwelling unit
that contains up to 3
bedrooms
1 additional space for every
2 additional bedrooms
2 for each dwelling unit
that contains up to 3
bedrooms
1 space per 10 parking
1 additional space for every stalls (minimum of 2
2 additional bedrooms spaces)
1 for each dwelling unit
with up to 1 bedroom
0.5 additional spaces for
every additional bedroom
at least 75% of residential
parking provided in an
enclosed structure (garage
or podium) screened from
view of public rights of way
1 carshare space for every 1 secure, ground -level
50-200 spaces on site space for every 4 units
MDR and HDR Zones in Tukwila (City of Tukwila)
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Tukwila Comprehensive Plan Medium- and High -Density Zoning Analysis
8
Tukwila's MDR and HDR Zoning Allow Densities Below What
Developers Typically Build in South King County
Tukwila's High Density Residential and Medium Density Residential zones
allow for just 50% lot coverage for multifamily structures (75% for
townhomes). In addition, the developable area is further reduced by the
following surfaces (78.50.085 B):
The footprint of an exclusive recreational facility
A proportion of a recreational facility footprint when contained
within a general use building as follows: the portion of the footprint
area occupied by a recreational facility divided by the number of
floors in that portion of the building
Vehicle circulation aisles between separate parking areas
Sidewalks
Paths
Other pedestrian/recreation facilities clearly designed to enhance
the pedestrian environment
On a one -acre site, 50% lot coverage minus the 400 SF per unit of
recreation space required for non -senior multifamily limits the maximum
number of units that can be built on site to roughly 15 in MDR zones
and 24 in HDR zones, but the zoning code limits this further to 14.5
units in MDR zones and 22 in HDR zones. This discrepancy may be due
to step -backs required for upper floors, which further limit the number of
units that could be built on site. Senior housing in the HDR zone is
exempt from the development area coverage maximum (78.50.085 C).
The multifamily properties in the HDR zone located northeast of the
intersection of I-5 and 1-405 were built between 1966 and 1989. The
densities of these properties range from 17 to 36 units per acre. The La
Vista Apartments, shown below, were built in 1970 and have a density of
36 units per acre. Current zoning would not allow for the construction of
apartments at this density in the HDR zone.
The La Vista Apartments in Tukwila, WA (CoStar)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 9
Five Housing Developments Have Been Completed in
Tukwila Since 2010 Jek �
There have been 46 new multifamily
buildings built in South King County
(including Kent, Burien, Des Moines, Renton,
SeaTac, and Tukwila) since 2010. Of these, 19
were in Renton and another 11 were in Kent.
The only multifamily properties completed in
Tukwila during this period were three senior
housing complexes with a total of 704 units,
one income -restricted building with 101
units and a mixed -use hotel and apartment
development. None of these projects could
be built under current code in the MDR or
HDR zones, and in fact three of
these projects utilized development
agreements to bypass local zoning
requirements.
W ®e!i
ase
Tukwila Village Senior Living
Year Built 2018 Units/Acre 57
Units 402 FAR 2.7
Avg. Unit Size 800 SF Parking Garage /
Surface
Construction 3-over-1 Avg. Rent/SF $2.40
Type
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Hotel Interurban / Airmark Apartments
Year Built 2018
Apt. Units
Avg. Unit Size
Construction
Type
371
589 SF
Steel Frame
Units/Acre
FAR
Parking
Avg. Rent/SF
110 (apts.
only)
3.4
Garage
$3.04
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
10
Cn
Five Housing Developments Have Been Completed in
Tukwila Since 2010
Holden Southcenter
Mariblu Southcenter
The Confluence
Year Built 2020 Units/Acre 118 Year Built 2020 Units/Acre 138 Year Built 2021 Units/Acre 78
Units 134 FAR 2.37 Units 166 FAR 3.67 Units 101 FAR 1.96
Avg. Unit Size 660 SF Parking Surface Avg. Unit Size 946 SF Parking Garage Avg. Unit Size N/A Parking Mixed
Construction Type 5-over-2 Avg. Rent/SF $5.58 Construction Type 5-over-2 Avg. Rent/SF $2.61 Construction Type 5-over-1 Avg. Rent/SF N/A
Note: This is not a typical age -restricted multifamily
property. It is more of a full -service senior and memory
care community.
Note: This is an income -restricted development, and many
typical market metrics are not applicable.
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
11
Residential Commercial (RCC) and Neighborhood
Commercial (NCC) Zoning regulations
Medium -density housing is also allowed in Tukwila's Residential
Commercial Center (RCC) and Neighborhood Commercial Center (NCC)
zones. While these zones lack the step -back requirements that are
problematic in MDR and HDR zones, they maintain some of the features
that make development challenging.
Both zones limit heights to three stories, except for on
International Boulevard where mixed -use buildings in the NCC
zone can be four stories.
In addition, both zones have significant setback requirements.
The NCC zone requires additional setbacks adjacent to LDR,
MDR, and HDR zones, despite the fact that the buildings allowed
in NCC are not taller or denser than housing in the HDR zone.
The required setback is one foot for every 1.5 feet of building
height.
Unlike the other zones, density in the NCC zone is determined
by building envelope for non -senior housing. However, this is
significantly limited by height, parking, and open space
requirements.
Like the MDR zone, density in the RCC zone is limited to 14.5
dwelling units per acre. This density is insufficient to meet the
goal of the zone, which is to support a diverse mix of residential
and retail uses.
Design Review Requirement
Minimum Lot Area
Lot Area per Unit
Senior Housing
Max Density
Senior Housing
Setbacks
Front
Second Front
Sides
Side (within 50 ft LDR/MDR/HDR)
Rear
Rear (within 50 ft LDR/MDR/HDR)
Maximum Height
Intl Blvd Mixed -Use
Recreation Space
Senior Housing
Parking
Residential
Office
Retail
Manufacturing
Warehousing
RCC
NCC
Multifamily over 1,500 SF
5,000 SF
3,000 SF
14.5 du/acre
Multifamily over 1,500 SF
726 SF
Determined by building envelope
60 du/acre
20 ft 6 ft (12 ft along Tukwila Intl Blvd S)
10 ft 5 ft
5 ft 10 ft
10 ft 1.5:1 (min of 10ft; max of 20 ft)
10 ft 10 ft
1.5:1 (min of 10ft; max of 20 ft)
3 stories / 35 ft 3 stories / 35 ft
4 stories / 45 ft
200 SF perdu (1,000 SF min) 200 SF perdu (1,000 SF min)
100 SF perdu
See 18.56
3 per 1,000 SF
2.5 per 1,000 SF
See 18.56
3 per 1,000 SF
2.5 per 1,000 SF
1 per 1,000 SF
1 per 2,000 SF
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 12
03
Urban Renewal Overlay (URO) Development Standards
For land within the city's Urban Renewal Overlay zone, there are
additional development standards that developers can request to use, if
their projects meet specific criteria (18.43.070). These criteria include:
At least 100 feet of the parcel's perimeter fronts onto Tukwila
International Boulevard
At least 75% of parking is within an enclosed structure screened
from view from public rights -of -way
The ground floor along Tukwila International Boulevard includes
active uses
Development must provide amenities that enable a high -quality
pedestrian experience
The property owner/manager must prepare a Transportation
Management Plan
Residential development must provide opportunities for tenants to
use a car -sharing program and make one space available at no
charge to a car -sharing program for every 50 to 200 residential
units on site
One secure, covered, ground -level bicycle parking space must be
provided for every four units
If a development within the URO meets these criteria, developers can
request to use the URO District supplemental development standards:
Building heights permitted up to 65 feet
Existing NCC setback standards
For multifamily, one parking space per each dwelling unit up to one
bedroom, plus 0.5 spaces for every additional bedroom in a
dwelling unit
The maximum number of dwelling units shall be determined by
building envelope rather than numeric density. Studios must be an
average of 500 SF per unit with no units smaller than 450 SF. No
more than 40% of units can be studios.
Ground floor live/work units can meet the NCC requirement for
ground floor retail or office space
Ground floor residential allowed in buildings or portions of
buildings that do not front an arterial
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 13
Key Takeaways: NCC & RCC Zones
The zoning requirements in the NCC and RCC zones reflect some of the
same challenges as the MDR and HDR zones. Like the MDR zone, RCC
limits density to 14.5 units per acre. The stated purpose of the RCC zone
is:
"To create and maintain pedestrian -friendly commercial areas
characterized and scaled to serve a local neighborhood, with a diverse
mix of residential, retail, service, office, recreational and community
facility uses." (18.20.010)
This density is low even for townhome developments and is unlikely to
support ground floor retail. In addition, the three-story height limit
further imposes feasibility challenges, especially in a mixed -use project.
The additional side setbacks in this zone when adjacent to LDR, MDR, or
HDR zones negatively impact feasibility without adding value to the
community. Structures in this zone have height limits just five feet higher
than in MDR zones, with the same density restrictions. It therefore does
not make sense to impose setbacks beyond what would be required
elsewhere.
Similarly, the purpose of the NCC zone is:
"To provide for pedestrian -friendly areas characterized and scaled to
serve multiple residential areas, with a diverse mix of uses." (18.22.010)
The NCC zone allows structures up to four stories, with density
determined by building envelope. However, requirements for parking,
ground floor retail, open space, and setbacks significantly limit what can
be built.
Setbacks are a challenge in this zone, especially when adjacent to LDR,
MDR, and HDR zones, where the maximum side setback can be up to 20
feet despite the fact that in most areas the allowed height in the NCC
zone is not greater than in residential zones.
Except for along Tukwila International Boulevard, structures in the NCC
zone are limited to three stories. As in the RCC zone, this is insufficient to
allow for ground floor active uses such as retail or office space. Typically,
these uses are subsidized by multifamily units, which command higher
rents and have lower vacancy rates. Two stories of multifamily above
ground floor retail is unlikely to pencil, even in markets with higher rent
than Tukwila.
In both zones, parking and recreational space requirements are a major
challenge. Because these types of properties are likely to be surface -
parked, high parking requirements have a significant effect on what can
be built. As in the MDR and HDR zones, recreation space requirements
should be lowered or tied to the gross lot area rather than a per unit
calculation. Additionally, the threshold for design review should be
increased significantly.
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 14
Ni
O
Recent Housing Development in Tukwila
• Tukwila has seen less multifamily development than neighboring cities over the past several
years, despite low vacancy rates and a need for new housing. The four newest housing
developments are two age -restricted senior housing projects, a mixed -use hotel and
apartment building, and an income restricted apartment building.
• Only one of the recent developments are in MDR or HDR zones, and three of four utilized
development agreements that allowed for taller, denser housing than allowed by city code,
including the development in the HDR zoning.
• The City's development pipeline includes three projects, two of which could add significant
new housing units to the local supply. However, the MDR and HDR zones do not appear to
be attracting new development.
New Multifamily Construction Since 2010 Has Largely Been
Built Near but Not In Tukwila
The map to the right shows the locations of the 44 new multifamily
buildings built in South King County since 2010. Despite concentrations of
retail and services in Tukwila, most of the new multifamily construction in
this area has taken place just outside city limits in Kent, Renton, and
SeaTac. On average, these new multifamily buildings have a density of 60
units per acre, the maximum density allowed for senior housing in
Tukwila's HDR zone.
Rent and construction costs do not differ substantially in Tukwila
compared with these neighboring cities, but Tukwila stands out as an
area that is not realizing the full benefit of investment into South King
County.
Recent Multifamily Developments in South King County (CoStar, LCG)
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Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 16
N
N
New, Higher -Density Construction Is Limited to the NCC and
TUC-TOD Zones
The higher density zones where Tukwila's limited new
construction is located are confined to commercial areas. The
NCC zone is primarily located along Tukwila International
Boulevard, northeast of the city's main Regional Commercial
(RC) area. An additional NCC zone is located along 40th Avenue
S, between Marginal Way and 128th Street. NCC allows
detached single-family homes, multifamily above
commercial (office or retail), and senior housing. Senior
housing in the NCC zone can be up to 60 units per acre.
The TUC-TOD Zone is located east of Southcenter along the
Green River. There is a Public Recreation Overlay (shown in
green stripes on the map to the right) that runs along the
river's west bank as well as through the eastern portion of the
zone. It is transit -oriented due to its proximity to the Tukwila
Sounder Station. The TUC-TOD zone allows for multifamily,
townhomes, mixed -use, senior housing, and retirement
communities.
Portions of the Tukwila Zoning Map Showing NCC and TUC-TOD Zones (City of Tukwila)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
17
None of the Multifamily Developments in Tukwila's Pipeline
Are in the MDR or HDR Zones
Tukwila currently has two multifamily projects in its development pipeline:
The Southard (3118 S 140th Street)
Prose (132 Andover Park E)
Vintage (10811 47th Avenue S)
The Southard (shown in the rendering to the right) is currently under
construction with an expected completion date of 2024. It is an affordable
development of for -sale rather than rental homes and is being developed by
the Homestead Community Land Trust. It is in the City's LDR zone. The City
and developer negotiated a development agreement allowing the project to
exceed the typical LDR density requirements — the project density is 12.6
units per acre, twice as many as are typically allowed in this zone. Funding
for the project is coming primarily from King County and the State of
Washington.
Prose is expected to have 285 units of non -senior housing on a 1.86-acre
site (153 units per acre). The site is zoned TUC-TOD.
The Vintage is expected to be a 272-unit senior housing development. The
development will be on three parcels with a combined total of 4.85 acres (56
units per acre). The parcels are zoned LDR and HDR.
Site Rendering of The Southard Development (CoStar)
3118 S 140th Street, Tukwila, WA
Est. Completion Date 2024
Units 18
Construction Type Cottage Cluster / Parking
Townhomes
Units/Acre
FAR
12.6
0.2
None
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
18
South King County Housing Market
Housing Market Dynamics
• Tukwila has the lowest market rent among South King County peer markets and has
seen the fewest new multifamily units delivered over the past year.
• The lack of construction has resulted in low vacancy rates but has not attracted new
construction activity.
• Tukwila's zoning code is more restrictive than the codes of peer cities that are
seeing more construction.
N
0)
Tukwila Is Attracting Less Development Than Neighboring
Cities with Similar Housing Markets
Tukwila is located along 1-5 in South King County, sandwiched between SeaTac on the
west and Renton and Kent on the east. Despite its proximity to Renton, Tukwila's
demographics and housing market are more similar to SeaTac's.
The chart to the right shows multifamily market indicators for the City of Tukwila
compared with CoStar submarkets in South King County. Tukwila has the lowest
market rent ($1,550) and rent per square foot ($1.93) of the comparison areas,
though rents grew faster year over year in Tukwila than in Federal Way, Kent, and South
Seattle. The stabilized vacancy rate in both Tukwila and CoStar's Burien/Des
Moines/SeaTac submarket was 4.10%, lower than in surrounding communities.
While Burien/Des Moines/SeaTac currently have 802 units under
construction, Tukwila has just 18. It trails the rest of South King
County in attracting multifamily construction.
The most recently completed multifamily development in the
Burien/Des Moines/SeaTac submarket is the Pointe by Vintage in
Des Moines. It is an affordable housing project built in 2023 at a
density of 110 units per acre with structured parking, likely enabled
by public subsidy.
Rendering of the Pointe by Vintage, Des Moines, WA (CoStar)
11�'kI l"I ' •
L U ---
Q2 2023 Multifamily Market Indicators in Tukwila and South King County Submarkets (CoStar)
Costar Submarkets
City of Burien/
Tukwila Des Moines/SeaTac South Seattle West Seattle
Kent Federal Way
Total Units 3,445
Units Under Construction 18
Stabilized Vacancy Rate 4.10%
12-Month Absorption (47)
Y-o-Y Rent Growth
Market Rent
Market Rent/SF*
*as of 7/14/2023
$1,550
$1.93
9,308
4.10%
(158)
$1,585
$1.97
7,066
335
5.10%
175
1.5%
$1,761
$2.53
11,854
514
5.40%
289
3.6%
$1,796
$2.45
13,453 8,586
477 200
5.60% 5.15%
119 (49)
-2.1% -3.4%
$1,844 $1,770
$2.14 $2.02
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
21
Relatively Low Vacancy Rates for Buildings with 8 to 20
Units Indicate Demand for Medium -Density Housing
The chart on the right shows the stabilized vacancy rates for existing
buildings with 8 to 20 units in South King County. While number of
units does not directly correlate to density, these buildings are generally
the types of moderate -scale housing typical of medium -density zones.
The table below shows the number of buildings and units meeting this
criteria for each city. Tukwila has the second lowest vacancy rate after
SeaTac at 3.34%. This is below what would typically be considered a
healthy market (5%). Renton has the highest vacancy rate for these types
of buildings at 5.34%. CoStar's forecast through 2028 does not indicate
that there will be a substantial rise in vacancy rates in these cities.
Tukwila's is expected to go down slightly by 2028, likely due to a lack of
new construction.
Stabilized Vacancy Rates for Buildings with 8-20 Units, South King County (CoStar)
7.00% History Forecast -
6.00%
5.00%
4.00%
3.00%
The relatively low stabilized vacancy rates across these cities, ranging
from 2.89% in SeaTac to 5.34% in Renton, indicates strong demand for
this type of smaller multifamily product. 2.00%
Number of Buildings and Units Surveyed (CoStar)
Tukwila SeaTac Burien Des Moines Kent Renton
1.00%
# of Bldgs 15 11 64 26 56 50 0.o0%
# of Units 194 142 772
311 684 615
- 1
\ 4.27%
1� �
'`� \ 3.34%
7
5.66%
2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028
Tukwila -SeaTac -Burien
Des Moines -Kent
Renton
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 22
oo
Tukwila Has a Particularly Low Vacancy Rate for Buildings
with 21 to 100 Units
The chart on the right shows the stabilized vacancy rates over time for
buildings with 21 to 100 units in South King County cities. As of 2023,
Tukwila has the lowest vacancy rate for these properties at 3.03%. SeaTac
and Tukwila have the smallest inventory of this property type, while Kent
and Renton has the largest. As with smaller multifamily buildings, the
vacancy rate in Tukwila is expected to go down even further by 2028 due
to lack of new construction.
Des Moines, Burien, SeaTac, and Tukwila all have vacancy rates below 4%
for these slightly larger multifamily buildings, indicating a strong demand
for this product type throughout South King County. In 2021, both
SeaTac and Des Moines had lower vacancy rates than Tukwila, but
Tukwila's vacancy rate has not bounced back like the other cities'. The
spread is expected to widen between Tukwila and SeaTac by 2028.
Number of Buildings and Units Surveyed (CoStar)
Tukwila SeaTac Burien Des Moines Kent Renton
Stabilized Vacancy Rates for Buildings with 21-100 Units, South King County (CoStar)
7.00% History Forecast
6.00%
5.00%
5.78%
L..,°ai_...'i11i
4.00% �����.�•%
.74%
.45%
5.90%
3.00%
2.00%
1.00%
# of Bldgs 28 17 36 29 61 51 a.0a%
# of Units 1,435 1,051 1,574 1,724 3,449 2,569
2.58%
2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028
Tukwila -SeaTac -Burien
Des Moines -Kent
Renton
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
23
Tukwila Has Had Only One New Multifamily Development
Completed Since 2018
Since 2014, a net total of 941 multifamily rental units
have been delivered in Tukwila — an average of 94
units per year. While this is above SeaTac's average of
82 units per year over that time, the projects that
have been delivered largely utilized development
agreements, which add significant time and cost to
a project, and benefitted from the city's short-lived
MFTE program, which was only very recently
reinstated, in limited areas of the city. Tukwila has
only seen one new multifamily project since 2018.
SeaTac and Tukwila are neighbors, with similar
demographics and comparable rents, each with LINK
light rail and BRT service. But between 2014 and
2023, 44% more net new units were delivered in
SeaTac than in Tukwila. In part, this is likely due to
differences in zoning between the two cities. SeaTac
has several residential zones, including UM-3,600,
UM-2,400, UH-1,800, and UH-900. The numbers
associated with the zones are the minimum lot sizes
per unit in square feet. The chart on the next page
contrasts residential zoning standards in SeaTac with
those in Tukwila.
Cumulative Deliveries Across South King County Cities, 2014-2026 (CoStar)
800 History Forecast
Hotel Interurban &
Tukwila Village it
700 Senior Living I 1
600
500
400
300
200
100
0
2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026
Tukwila SeaTac -Burien
Des Moines
Kent
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 24
W
Small Changes to Zoning Regulations Could Have a Big
Impact
SeaTac's zoning regulations for medium- and
high -density residential zones are not radically
different from Tukwila's. In Tukwila, the minimum
lot area per unit in medium density zones is 3,000 SF
while in SeaTac it ranges from 2,400 SF to 3,600 SF.
The lot area per unit and maximum density in
Tukwila's HDR zone are similar to those in SeaTac's
UH-1,800 zone. Even setbacks are not too dissimilar in
the two cities' zones. The major differences are the
requirements for step -backs, height, and minimum
recreation space per unit.
Unlike Tukwila, where all multifamily housing in MDR
and HDR zones must have front, side, and rear step -
backs on upper floors, SeaTac only requires upper -
floor rear step -backs on UH lots that directly abut
UL and UM zones. SeaTac also allows for an extra
story of height in its medium- and high -density
zones compared with Tukwila's.
And where Tukwila requires 400 SF of recreation
space per unit, SeaTac requires between 120 SF and
200 SF depending on the unit size. SeaTac also
does not require lot coverage to be net of this
recreation space.
Comparison of Zoning Regulations in Tukwila and SeaTac Medium- & High -Density Zones
Minimum Lot Area
Lot Area per Unit
Maximum Density
Senior
Non -Senior
Setbacks
Front
Second Front
Sides
Rear
Step -Backs
Front
Side
Rear
Adj. to UL Zones
Adj. to UM Zones
Maximum Lot Coverage
Multifamily
Townhomes
Maximum Height
Minimum Rec Space/Unit
2-Bed
1-Bed
Studio
Tukwila
Medium Density
High Density
UM-3,600
SeaTac
UM-2,400
UH-1,800
UH-900
8,000 SF
3,000 SF
14.5
14.5
15 feet
7.5 feet
10 feet
10 feet
20 ft (2nd floor)
30 ft (3rd floor)
10 ft (2nd floor, TH only)
20 ft / 10 ft TH (3rd floor)
20 ft / 10 ft TH (2nd & 3rd floor)
30 ft if adjacent to LDR
50%
75%
30 feet
400 SF
400 SF
400 SF
9,600 SF
2,000 SF
60
22
15 feet
7.5 feet
10 feet
10 feet
20 ft (2nd floor)
30 ft (3rd floor)
45 ft (4th floor)
20 ft / 10 ft TH (2nd & 3rd floor)
30 ft if adjacent to LDR
30 ft / 20 ft TH (4th floor)
20 ft / 10 ft TH (2nd & 3rd floor)
30 ft if adjacent to LDR
30 ft / 20 ft TH (4th floor)
50%
75%
45 feet
400 SF
400 SF
400 SF
N/A
3,600 SF
12
12
15 feet
5 feet
10 feet
55%
40 feet
200 SF
160 SF
120 SF
N/A
2,400 SF
18
18
15 feet
5 feet
10 feet
55%
40 feet
200 SF
160 SF
120 SF
N/A
1,800 SF
24
24
10 feet
5 feet
5 feet
35 ft height limit
within 10 ft of
setback
40 ft height limit
within 10 ft of
setback
75%
55 feet
200 SF
160 SF
120 SF
N/A
900 SF
48
48
10 feet
5 feet
5 feet
35 ft height limit
within 10 ft of
setback
40 ft height limit
within 10 ft of
setback
75%
55 feet
200 SF
160 SF
120 SF
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 25
SeaTac's Highest Density Residential Zone Has Few
Limitations
SeaTac also has residential and commercial zones that allow for
significantly higher lot coverage and height standards, without
restrictions on density. The Urban High -Urban Center Residential
(UH-UCR) and Community Business -Urban Center (CB-C) zones,
shown in the table to the right, allow for much higher -intensity
development than can be found in Tukwila's high density
residential zone. The UH-UCR zone allows for 90% lot coverage
with limited setbacks and no upper -floor step -backs. On lots
adjacent to lower -intensity zones, a ten -foot landscaping buffer is
required. Height is limited in both zones by FAA and fire
department regulations.
While Tukwila's HDR zone is more comparable to SeaTac's other
high density residential (UH) zones, Tukwila lacks a high -density
residential zone that allows for taller, denser, more urban -style
multifamily buildings. SeaTac utilizes UH-UCR zoning in targeted
areas, such as along S 154th Street, just west of the Tukwila
International Boulevard Link station. On the east side of Tukwila
International Boulevard, Tukwila has zoned this area as a mix of
Regional Commercial (RC) and High Density Residential.
Developers who want to build transit -oriented development
near the Link station are more likely to build in SeaTac, where
the UH-UCR zone has fewer restrictions than Tukwila's HDR and
RC zones.
Minimum Lot Area
Setbacks
Min. Front
Max. Front
Min. Side
Min. Rear
Maximum Lot Coverage
Maximum Height
Landscape Standards
Street Frontage
Building Facade
Side/Rear Yards
Side/Rear Buffer
SeaTac
UH-UCR
CB-C
7,200 SF (3,000 SF for small lot
single family)
0
20 ft
5 ft
5 ft
90%
Limited by FAA & fire
department regulations
5 ft
5 ft
5 ft
10 ft
N/A
0
10 ft
N/A
N/A
75%
Limited by FAA & fire department
regulations
5 ft
5 ft
5 ft
10 ft
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 26
W
IV
Non -Senior Housing Attracts Younger Workers & Benefits
the City and Local Businesses
The emphasis on senior housing in the City's code is unusual,
especially given the city's relatively low median age of 36. According
to Esri, just 12.8% of Tukwila residents are 65 or older, while 75.5%
are under the age of 55. These households, many of whom include
prime -age workers, have higher incomes and more spending
power than households headed by adults over 55 years old.
However, the emphasis on building senior housing in Tukwila's zoning code
limits the future growth of this younger, higher -earning demographic. If the
City is interested in incentivizing senior housing, there are potential
avenues for this that do not simultaneously disincentivize housing that
supports other demographics.
Income Distribution of Seniors and Non -Seniors in Tukwila (Esri)
The graph to the right shows the distribution of income for 25%
households headed by adults under 55 vs. those headed by adults 55 ■ <ss ss+
or older. Younger households are more likely to make over
$50,000 per year (72% vs. 61%). The median household income for 20%
householders aged 45-54 in Tukwila is $86,815, while for
householders aged 65-74 it is $60,169. 15%
In fact, according to Esri the top demographic group in Tukwila is
"Bright Young Professionals" — young, educated, working adults with 10%
a median age of 33 and a median household income of $54,000 with
a higher -than -average labor force participation. Over 57% of these 5%
households are renters. Young, educated, upwardly mobile
households tend to spend their money on housing, food, apparel,
and entertainment, bolstering the local economy. Along with more °%
local spending, higher -wage households also contribute more in ,,�°°° �tib.,°� �,��°'�� ����°° ��b,D°° �°�°°° ��°°° ���°°° °°o°°x
taxes, supporting the fiscal health of the city. o°° o°° o°° o°° o°° o ' o Y 6ti
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 27
Common Multifamily Prototypes in South King
County
• Garden and podium -style apartment buildings are the most feasible types of multifamily
developments in South King County.
• Garden -style housing is typically 20 to 25 units per acre, while podium -style construction is
typically at least 60 units per acre.
• Due to the significant cost associated with structured parking (typically $45,000 per stall),
most South King County developments are built with surface parking. Structured parking is
generally found in cities or neighborhoods with higher rents and zoning that allows for
taller, denser construction.
• The following prototypes were all built after 2010 in South King County.
W
Townhomes, Garden Apartments, and Low -to -Mid -Rise
Podium Construction Are Common in South King County
Miller Creek Court
215 S 162nd Street
Burien, WA
Year Built 2014 Units/Acre 21
Units 46 FAR 0.72
Avg. Unit Size 1,337 SF Parking Surface / Garage
Construction Type Townhomes Avg. Rent/SF $1.80
Astral Apartments
6329 S 212th Street
Kent, WA
Year Built 2023
Units 155
Avg. Unit Size 661
Construction Type Garden Style
Units/Acre 24
FAR 0.54
Parking Surface
Avg. Rent/SF $2.69
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
29
Townhomes, Garden Apartments, and Low -to -Mid -Sized
Podium Construction Are Common in South King County
Ethos
2200 W Meeker Street
Kent, WA
Year Built 2019
Units 288
Avg. Unit Size 774 SF
Construction Type Garden Style
Units/Acre 14
FAR 0.52
Parking Surface
Avg. Rent/SF $2.66
■
Year Built
Units
Avg. Unit Size
Construction Type
Ka i ros
2030 W Meeker Street
Kent, WA
2022
208
784 SF
5-Over-2
Units/Acre
FAR
Parking
Avg. Rent/SF
35
0.8
Garage / Covered
/ Surface
$2.91
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
30
W
0)
Townhomes, Garden Apartments, and Low -to -Mid -Sized
Podium Construction Are Common in South King County
Viewpoint Apartment Homes
21428 International Boulevard S
SeaTac, WA
Year Built 2012 Units/Acre 60
Units 90 FAR 0.88
Avg. Unit Size 625 SF Parking Structured / Surface
Construction Type 4-over-1 Avg. Rent/SF $2.99
Altitude Apartments
1600 Benson Road S
Renton, WA
Year Built 2015
Units 120
Avg. Unit Size 987
Construction Type 4-over-1
Units/Acre 45
FAR 0.8
Parking Surface
Avg. Rent/SF $2.24
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
31
Density and Rent Determine the Ability to Provide
Structured Parking in South King County
Adriana Senior Apartments
22525 7th Avenue S
Des Moines, WA
Year Built 2018
Units 119
Avg. Unit Size 620 SF
Construction Type 5-Over-1
Units/Acre
FAR
Parking
Avg. Rent/SF
178
3.44
Structured
$2.64
Midtown 64
24615 64th Avenue S
Kent, WA
Year Built 2020
Units 365
Avg. Unit Size 782
Construction Type 3-Over-1
Units/Acre 37
FAR 0.73
Parking Surface
Avg. Rent/SF $2.60
Tukwila Comprehensive Plan Medium- and High -Density Zoning Analysis
32
W
W
New Typologies
• Innovations in housing design and materials allowing more units on smaller lots are
changing the way cities plan for density.
• The City's building and zoning codes should be flexible enough to allow for these new
typologies to enable the City to benefit from a wider variety of housing types.
• Point access blocks (also known as single staircase buildings) are now legal in Seattle, and
cities can adopt Seattle's building code changes starting in 2026. Preparing Tukwila's zoning
code for those changes now will help developers understand and adapt to city rules prior
to legalization.
• Allowing middle housing on residential lots increases opportunities for homeownership.
SB 5491 Legalized Point Access Blocks Statewide in
Washington
Point Access Blocks, also referred to as Single Staircase buildings, are
characterized by dwelling units built around a single staircase
and elevator core in the center of the building. While these are generally
allowed under the International Building Code up to 3 stories, Seattle
allows them to be up to 5 or 6 stories.
SB 5491 allows cities with adequate fire services to adopt Seattle's
building code changes starting in 2026. According to a 2021 report by
Larch Lab for the City of Vancouver, British Columbia, the benefits of
point access blocks include:
"increased livability, reductions in embodied carbon, reductions
in operational carbon, increased accessibility and adaptability,
potential cost savings, increased climate resilience, and
increased urban resilience - with no discernable reduction in
safety."
Importantly, single -staircase buildings allow for a wider variety of unit
types and sizes, including 3- and 4-bedroom units suitable for families.
These buildings are also typically less expensive to build, especially those
that are 5 stories or more. At the same time, these buildings allow for
higher -density construction on smaller lots due to the space saved by not
requiring a second staircase.
Point Access Block Diagram (Second Egress)
N
N
co
Code 2018
Seale 6 gEedioXiit
1006 '3.
Gore
Ntior' le
oreoen 10' dIt or's
ex t SsaR e ProPem
n¢h
With oneesto xit to per Pro
roan 6 storeys
dwelling exit conditions P
ir
max. o Single
rook �
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 34
Examples of Single -Staircase / Point Access Block Buildings
Capitol Urban Hill Apartments, Seattle, WA (Second Egress)
The High Street Apartments, Melbourne, Australia — a CLT Point Access Block
Apartment Building (Gardiner Architects)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
Detached Single -Family
Houses
Middle Housing Could Provide an Opportunity for Gentle
Density in LDR and MDR Zones
Missing middle housing can refer to a wide range of housing types,
including small "plexes" with two to six units, townhomes, cottage
clusters, and low-rise apartment buildings. HB 1110, which passed through
the Washington Legislature in 2023, requires cities in King County with
25,000-75,000 residents to allow two units per lot in all predominantly
residential zones and four units per lot near major transit stops.
However, Tukwila should allow middle housing at a higher density
than is required under HB 1110, especially in the city's LDR and MDR
zones. Portland's Residential Infill Project (RIP), which went into effect in
2021, allows buildings up to 4 units on nearly all residential lots, and up to
6 units if half are affordable at 60% AMI. To incentivize the construction
of these middle housing types rather than large single-family homes in
these areas, Portland capped the floor area ratio (FAR) of single-family
Missing Middle Housing Typologies (Opticos)
lujj
eau
a 4I� Pex: Live- MidRise
�'- �i `C �1'� F- aw• Townhouse MUICplez 5[aClked work
Courtyard Cottage Med um Duplex: Fourplex: Buiidin Courl
SideBySide. Stacked g — —
Stacked _ Missing Middle Housingxe - M1
homes, providing a bonus with each additional unit. The incentivization of
multi -unit buildings has helped Portland increase the housing supply
while minimizing demolitions. Since 2021, 271 duplex, triplex, and four-
plex units have been built on 81 lots, resulting in the demolition of just 46
houses. Middle housing could potentially help Tukwila increase its
housing supply in lower -density zones while mitigating displacement.
Portland Residential Infill: Lots & Demolitions vs. Number of Units Permitted
(City of Portland)
300
200
10D
Q
12
lots
Total Lots • Demolished units Constructed LIMN
24 houses
1.2:1
126
units
House, House wlADU*
81 +
lots
41 ho®a
3.4:1
271
units
Duplex, Triplex, Fourplee*
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 36
N
Middle Housing Helps Prevent Displacement and Provide
Opportunities for Homeownership and Wealth Building
Since it went into effect in 2021, RIP has been revised to allow a wider
variety of housing types, including side -by -side six-plexes and detached
duplexes. ADU rules have also been adjusted — the maximum size of an
ADU is no longer tied to the size of the primary structure. Portland
incentivized the building of four-plexes by tying FAR to the number of
units on site, with bonuses for each additional unit up to four.
An analysis of RIP conducted by Cascadia Partners for the City of Portland
found the following benefits:
Middle housing uses land nearly three times more efficiently
than single houses
Over 99% of middle housing units had two or more bedrooms
Building size limits prevented the construction of large,
expensive new single-family homes (sometimes called
McMansions)
Legalizing middle housing resulted in more housing units and
fewer demolitions, limiting residential displacement.
Eliminating parking minimums for middle housing helped
increase the feasibility of building four-plexes
The case studies included in the report show that middle housing units
are less expensive to purchase than single family homes, but the
number of units still allows developers to realize a profit. In the
Creston -Kenilworth neighborhood, a developer built three four -unit
townhome structures on three separate lots (12 units total). The
developer purchased the lots for $1.23 million. The average price per
townhome unit was $419,900 — the median sale price of a single-family
home in that neighborhood is $575,000 as of July 2023. The price for all
12 was an estimated $5.04 million, roughly four times the cost of the land.
The middle housing study currently being conducted by MAKERS and the
Black Homeownership Initiative for the City provides more community -
based recommendations for this housing type.
Creston -Kenilworth Townhomes in Portland, OR (Redfin)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 37
Examples of Middle Housing
Four -Unit Building, Portland, OR (Property Shark)
"Shake Shacks" Townhomes, Seattle, WA (Hybrid Development)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
38
Feasibility Challenges
• Tukwila's MDR and HDR zones have a number of provisions that challenge
feasibility for the most common housing types.
• Rules governing height, density, step -backs, and lot coverage prevent the type of
development that conforms to the City's stated goals in these zones.
0)
The Tukwila TOD Development Housing Strategies Plan
Demonstrates the ImpsstaWoning on Feasibility
ECONorthwest conducted a feasibility analysis as part of the Tukwila Transit -Oriented Development Housing Strategies Plan (2021) to determine which code
requirements are most likely to impact feasibility. They used a residual land value (RLV) approach benchmarked against typical land prices ($50-$70 PSF)
in Tukwila. RLV is a calculation of how much a developer could pay for land given development costs and an expected return. If RLV is below the
market value of land, the development is not feasible without additional incentives. The findings were organized by prototype and are summarized in
the tables below. For 4-story wood frame apartments, parking and recreation space requirements currently in the City's zoning code negatively impact
feasibility. Tax incentives like an MFTE program as well as changes to recreational space and step -back requirements would improve the feasibility of a 4-
over-1 podium -style apartment building. (Note: the City's current HDR zoning has a maximum height of 45 feet, prohibiting 5-story buildings.)
Feasibility Findings based on RLV from the 2021 Tukwila TOD Housing Strategies Plan (City of Tukwila, ECONorthwest)
Prototype Parking
Recreation Space
Townhomes Reducing requirement from 2 spaces to 1 improves RLV by $2.40 PSF Defining recreational space by share of lot rather than square foot per
but the RLV is still lower than typical land prices. unit increases RLV by $14.80 PSF. The RLV of $123.20 is at the lower
end of land prices in Tukwila.
4-Story Wood Frame
Reducing required parking from 1.5 spaces to 1 improves RLV by
$14.30 PSF, making this prototype feasible at the entire range of
typical land values.
The alternative recreational space requirement improves RLV by
$13.30 PSF. When combined with a reduction in required parking, the
RLV is higher than the typical cost of land in Tukwila.
Prototype Structured Parking Mixed Income Recreational Space Step —Backs
4-over-1 Podium
Not feasible with or without structured 12-year MFTE program feasible Feasible with alternative recreational Not feasible with step -backs.
parking. Structured leaves a negative due to tax abatement; Inclusionary space requirement.
RLV. Housing without a tax abatement
is not feasible.
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 41
Step -Back Requirements and Height Limits in the HDR Zone
Prevent Podium -Style Construction
As discussed previously in this report, one of the most common types of
housing built in South King County is 4-over-1 podium -style construction.
Although podiums have a higher overall building cost, the density of
these projects improves their feasibility (especially if parking requirements
are relatively flexible). However, Tukwila's HDR zone requires front, side,
and rear step -backs above the ground floor, significantly limiting density
and therefore feasibility. The chart on the right, taken from the TOD
Housing Strategies Plan (2021) shows the impact of these step -backs on
residual land value.
ECONorthwest found that the current zoning code's upper floor step -
back requirements reduce density by 8.7 dwelling units per acre for 4-
over-1 projects, a reduction of 11%. This results in a $26 per square foot
decrease in residual land value. Assuming typical land prices between $50
and $70 per square foot, the step -back requirements directly impact
feasibility, even if other requirements remained.
For 4-over-1 projects, ECONorthwest estimated that the typical density
would be 79.9 units per acre — higher than what is currently allowed in
the HDR zone (60 units per acre for senior housing, 22 units per acre for
non -senior housing). It also assumes a height limit higher than 35 feet.
The current density limits in the HDR zone are more suited to garden -
style construction, which is very rarely subject to step -back
requirements. The fact that no multifamily housing has been built
recently in the MDR or HDR zones sends a signal to the City that the
current zoning requirements do not reflect the reality of development
economics in South King County.
Feasibility Impacts of Step -Back Requirements (City of Tukwila, ECONorthwest)
4-over-1
4-over-2
Dwelling Units per Acre (DUA)
79.9
71.1
-8.7
161.2
122.0
-39.2
Floor Area Ratio (FAR)
1.83
1.77
-0.06
4.50
3.76
-0.74
RLV psf
$ 52
$ 26
-$26
-$29
-$87
-$58
Park 16 Garden -Style Apartments in Federal Way — No Upper Floor Step -Backs
(CoStar)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
42
CO
Developers Should Have Flexibility over How Much
Structured Parking to Provide
Tukwila's zoning code requires that multifamily properties provide two car
parking spaces for each dwelling unit that contains up to three bedrooms,
and one additional space for every two bedrooms (i.e., a 5-bedroom apartment
would be required to have three parking spaces). One bicycle space is also
required for every ten parking stalls, with a minimum of two bike parking
spaces.
However, multifamily and mixed -use housing in the Urban Renewal Overlay
(URO) has slightly different parking requirements. In the URO, multifamily and
mixed -use housing must have one car parking space for each dwelling unit
with up to one bedroom and 0.5 additional spaces for every additional
bedroom (i.e., a 3-bedroom unit would need 2 parking spaces). 75% of this
residential parking must be in an enclosed structure, screened from view of
public rights of way. In addition, there must be one carshare space for every
50 to 200 spaces on site, and 1 secure, ground -level bicycle parking space
for every four units.
Typically, structured parking is estimated to cost at a minimum $45,000 per
space, while surface parking costs just $2,500 per space. For a 22-unit building
with 30 parking spaces in the URO, 23 structured spaces would cost over $1
million to build, nearly 14 times as much as 30 surface spaces. Garden -style
apartment buildings, like the Astral Apartments in Kent, which are typically up
to 25 units per acre, do not have the density to support the high cost of
structured parking, even when rents are relatively high. The Kairos, a 5-over-2
podium -style building completed in 2022 with an average rent of $2.91 per
square foot, has a mix of garage, covered, and surface parking.
While it makes sense from a placemaking perspective that the City would not
want large surface parking lots in an area intended to be walkable, there are
other ways to achieve this, such as requiring that parking be located behind
the housing, which could then front directly onto the street. The Alta Civic
Station in Gresham, Oregon (shown below) is an example of this.
Ultimately, developers will not build housing at this density if it is required to
include structured parking, even at the lower ratio required in the URO.
Developers should have the flexibility to determine — based on rent prices,
material costs, land configuration, and other factors — whether and to what
extent structured parking makes sense for their project.
Alta Civic Station Apartments, Gresham, OR (CoStar)
11,11.
n,
cid
®0
P 9 CI itEIllIm
IE II
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 43
Maximum Lot Size Calculations Should Be Calculated from
Gross Land Area
According to Tukwila's zoning code (18.50.085):
In the MDR and HDR zones the maximum percent development area
coverage shall be 50%, less the following surfaces:
�. The footprint of an exclusive recreational facility;
2 A proportion of a recreational facility footprint when contained within
a general use building as follows: the portion of the footprint area
occupied by a recreational facility divided by the number of floors in
that portion of the building;
3. Vehicle circulation aisles between separate parking areas;
4. Sidewalks
5. Paths; and
6. Other pedestrian/recreation facilities clearly designed to enhance the
pedestrian environment.
This is relatively atypical of zoning standards, the majority of which
calculate the maximum lot coverage based on gross land area. In addition,
other regulations already significantly limit the area on which housing can be
built. The basic diagram to the right demonstrates the impacts of some
space regulations on a mid -block, 1-acre plot of land in the HDR zone.
The box diagram below shows the amount of space that would be
dedicated to parking, recreation space, and setbacks on a 1-acre property.
This does not take into account paths, sidewalks, other pedestrian facilities,
or sidewalks. While parking itself (other than circulation aisles) is not
excluded from the maximum lot coverage calculation, surface parking is
typically 350 SF per space — for a 22-unit building, Tukwila requires 44
parking spaces (15,400 SF) and 8,800 SF of recreation space. The 17,266 SF
left for building is under 40% of the total site area.
While the current code
language is unclear, City
planners interpret this regulation
to mean that exempt spaces are
subtracted from total site area
before the 50% lot area is
calculated. In this case, that
would leave a buildable land
area of 17,380 SF. Calculating
lot coverage based on net area
is unconventional and
significantly limits
development.
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 44
01
O
Aligning Zoning Code EL Housing Goals
• Tukwila's zoning code specifies goals for each zone, which align with the City's goals
for housing production.
• However, as currently implemented the MDR and HDR zones are not meeting these
goals.
• Aligning the City's zoning code and housing goals will require removing or
adjusting barriers to feasibility.
Loosening Restrictions in MDR and HDR Zones Will Improve
Feasibility and Provide DevelopemaMore Flexibility
The major impediments to housing production in the MDR and HDR zones
include:
• Density Restrictions: Current density restrictions (14.5 units per acre in MDR
zones and 22 units per acre in HDR zones) significantly limit what can be
built, impacting the feasibility of housing types typical in South King County,
especially when compounded by other restrictions.
• Minimum Lot Coverage: The minimum lot coverage is 50% in both MDR
and HDR zones, but it is further reduced by recreational space and vehicle
circulation requirements. In many cases, this reduces density beyond the
already tight restrictions. Typically, jurisdictions calculate minimum lot
coverage based on gross lot area.
• Lot Area per Unit. Tukwila requires a high lot area per unit ratio, at 3,000 SF
for MDR and 2,000 SF for HDR. This requirement is not needed in
conjunction with the already low lot coverage ratio. It impacts feasibility by
forcing developers to build fewer, larger units.
• Upper Floor Step -Backs: While the setbacks required in MDR and HDR
zones are fairly typical (15-foot front setbacks, 10-foot side setbacks), the
additional step -backs required for upper floors significantly limit the number
of units that can be built. The townhome, garden, and podium -style projects
that typically get built in South King County have relatively uniform facades.
Requiring each floor to be set back an additional 10 feet or more makes
Tukwila a less appealing place to add new housing than other nearby cities
with fewer restrictions. While some jurisdictions in the area utilize rear
step -backs for upper floors on lots abutting a low -density residential district,
Tukwila's requirement of step -backs on all upper floors and all sides of a
building is unique.
• Recreation Space (Non -Senior Housing): Tukwila requires 400 SF of
recreation space per unit in non -senior housing. This recreation space then
further limits the maximum lot coverage. Reducing the required recreation
space to 100 SF per unit, as is the case in Tukwila's senior housing
regulations, or even 160 SF per unit in line with SeaTac's zoning regulations,
would help improve feasibility.
• Parking Requirements. Tukwila requires two spaces per multifamily
dwelling unit up to three bedrooms outside of the URO. This does not allow
developers to "right size" parking based on market demand. Typically, even
in the absence of parking requirements developers will build parking to
meet demand. Therefore, parking minimums should ideally be low to allow
developers the flexibility to respond to changes in the market.
• Structured Parking in the URO: Tukwila's Urban Renewal Overlay includes
land zoned MDR and HDR. In this zone, 75% of required parking for
multifamily properties must be in a structure (either a garage or podium).
This is not feasible for projects at the densities required by Tukwila's zoning.
Even in larger garden and podium style projects in South King County, much
of the parking is in surface lots due to the rents in the area and the high cost
of providing structured parking (typically at least $45,000 per space for
above -ground structures and over $60,000 per space for below -ground).
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 46
01
IV
Minimum Lot Size per Unit and Upper Floor Step -Backs Limit
What Can Be Built in Tukwila's MDR Zone
The purpose of Tukwila's Medium Density Residential (MDR) zone is:
To provide areas for family and group residential uses, and [serve] as an
alternative to lower density family residential housing and more
intensely developed group residential housing and related uses.
(18.12.010A)
The maximum density is 14.5 dwelling units per acre, compared with
6.7 units per acre in the Low Density Residential (LDR) zone. The
townhome condos shown in the photo to the right are 2,138 square foot
two bed, two and a half bath units in Renton. There are seven total units
on just under half an acre of land — a density of 15.9 units per acre. Redfin
estimates that each unit is worth just under $1 million.
These condos would not be able to be built in Tukwila's MDR zone due
to the City's density and massing regulations, which require second floor
step -backs of 20 feet at the front of the building. According to the King
County Assessor, there is less than 3,000 square feet of land per dwelling
unit, which would also be prohibited in Tukwila's MDR zone. These units
are large, with ample landscaping protecting privacy from the street. If
this is the type of medium -density housing Tukwila hopes to attract
in its MDR zone, it should address lot coverage, minimum lot size per
unit, and second and third floor step -backs.
Condo Townhomes at 1750 Lake Washington Boulevard N, Renton (CoStar)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
47
Tukwila's Density Standards in HDR Zones Differ Widely for
Senior and Non -Senior Housing
The purpose of Tukwila's High Density Residential (HDR) zone is:
To provide a high -density, multiple -family district which is also compatible with commercial
and office areas. (18.14.010A)
The maximum density is 22 units per acre for non -age -restricted housing and 60 units per acre for
senior housing. Heights are restricted to 45 feet (approximately four stories) and, as in the MDR zone,
the maximum lot coverage is 50%. The maximum lot size per unit is 2,000 feet — lower than in the MDR
zone but still above what is typical for a high -density multifamily district. In Des Moines, for example, the
highest density residential district (RM-900) requires just 900 SF of lot area per dwelling unit.
The Mill Creek Vista Apartments in Kent, shown at the top right, is a 12-unit building on a 0.55-acre site
— a density of 22 units per acre. The gross lot size per unit is 1,997 SF, just under the minimum allowed in
Tukwila's HDR zone. It is surface parked, as is typical for garden -style housing which does not have the
density needed to support structured parking.
The Bristol at Southport is a 383-unit apartment complex on 6.35 acres of land — a density of 60 units
per acre, the maximum density for senior housing in Tukwila's HDR zone. At 4 stories, this is the kind of
project that could be built in HDR zones if Tukwila used the standards for senior housing across the
board and relaxed step -back and lot coverage requirements. The gross lot size per unit at The Bristol at
Southport is 722 SF. Like Mill Creek Vista, this project is surface -parked.
Neither Mill Creek Vista nor The Bristol at Southport conform to Tukwila's requirement that upper
stories be set back. This requirement makes it extremely challenging to build garden -style apartment
complexes, especially given the lot size and coverage standards. The City should allow all multifamily
in the HDR zone to be 60 units per acre and eliminate upper -floor step -back requirements.
Mill Creek Vista Apartments, Kent (CoStar)
The Bristol at Southport, Renton (CoStar)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
48
01
Tukwila Should Also Consider Changing Its Design Review
Requirements
While the zoning code changes suggested above will have the biggest As Tukwila revises its zoning code to allow the types of multifamily
impact on feasibility, discretionary reviews can add time, expense, and housing that would benefit the community, it should consider allowing
uncertainty to projects beyond what can be covered by expected conforming structures to go through an administrative rather than a
revenues. discretionary review. This would reduce the time and expense
Design review by Tukwila's Board of Architectural Review (BAR) is associated with predevelopment and improve feasibility, especially for
required for: smaller projects in the MDR zone.
Sites with gross building square footage over 10,000 SF in MUO, O,
RCC, NCC, RC, RCM, and C/LI zones
Any sites in the NCC, MUO, or RC zones in the Tukwila
International Boulevard corridor
Multifamily structures in the MDR and HDR zones
Any new non -single family homes built in the shoreline jurisdiction
New residential or mixed -use buildings up to 50 dwelling units in
the TUC zones (Type 2 decision); new residential or mixed -use
buildings with 50+ units in the TUC zones (Type 4 decision)
These reviews increase the equity needs of developers as well as financial
risk. As a result, developers may choose to build in nearby cities where
the lower -density projects the City expects in the MDR and HDR zones
can go through administrative approvals.
Tukwila Village Senior Living (CoStar)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
49
Opportunity Areas
• Opportunity areas are locations with the kind of amenities that support density. These
amenities typically include public services, local recreational and community spaces, and
essential retail like pharmacies and supermarkets. Increasing density in amenity -rich
locations helps reduce the number of car trips and promotes active transportation. The
presence of nearby amenities such as parks and libraries also allows people to live more
comfortably in smaller units.
• The map on the following page shows that there are amenity -rich areas in Tukwila
surrounded by land zoned low -density residential (LDR).
• The City should consider increasing density along these corridors.
C31
C,
Amenities Are Concentrated in Southcenter and along
Tukwila International Boulevard
The map on the right shows the major amenities and points of interest in and adjacent
to Tukwila. Amenities are concentrated in the Southcenter area, specifically in the
TUC-P, RUC -RC, and TUC-TOD zones, as well as along Tukwila International Boulevard
and S 144th Street. These amenity -rich areas are typically where higher density housing
should be built.
While there are some MDR and HDR zones set back from International Boulevard, the
largest HDR zones are separated from amenity -rich neighborhoods. The largest
HDR zone in the City is north of 1-405 and east of 1-5. While there are some parks and
places of worship there, it is separated by a highway from the retail, transit, and public
services in Southcenter. Similarly, while the small HDR-zoned area north of
Southcenter Boulevard is adjacent to the RapidRide F Line that connects to Burien and
Renton, it is nearly a mile to the nearest grocery store, and there are few amenities
within walking distance.
The City should consider expanding the HDR zone along S 144th Street, where there
is a concentration of public amenities including schools and parks. In addition, the City
should ensure that the TUC zoning in Southcenter allows the kind of high -density and
mixed -use development that pairs well with retail.
Tukwila
Amenities with
Zoning
r=; City Limit;
Rsoynda,Commute.Rel
Railroad
ea LINK Light Red
Fluhndays
Points of Interest by Type
Ju Education
eN Faith-Baastl Institution
L Ftnenytelserv,�=
E McMats&Grocery
Parks a Community canters
• Pal. Serene,
Retail
GTransportaton
Zoning
UDR
MDR
Lou
HI
LI
- MlotH
MUO
ILCC
RC
RCC
_ RCM
- TUC -CC
Tue-P
EMr
- TUC -TOR
TUC.toy wp
0 2.500 5,000 Feet
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SoutM120011t
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Station 1
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 51
Conclusions & Recommendations
C31
co
Recommendations
• In order to increase the feasibility of housing in MDR and HDR zones and attract
more development, the City's zoning code will need to be more flexible, with fewer
barriers to housing construction.
• As the City weighs changes to its zoning code, it should also consider expanding
higher density zones in areas where residents can reach essential services without a
car.
MDR and HDR Zones Should be Modified to Allow the Types
of Housing Most Common in South King County
While Tukwila has seen very limited new construction, other South King
County cities with similar rent prices and demographics have seen more
investment. This is not because Tukwila is less attractive or lacks the
transportation infrastructure of these other cities. It is mainly due to
Tukwila's zoning code, which makes it difficult to build the types of
multifamily housing that are most feasible given local rents (typically
between $2.60 and $2.90 per square foot for new construction). These
include townhomes, middle housing, garden -style and urban garden -
style apartments, 4-story wood frame apartments, and 4-over-1 podium
construction.
Tukwila's zoning code changes should begin with determining what
kinds of housing the City wants to see in its MDR and HDR zones. LCG
recommends the following:
MDR: townhomes, middle housing, and low -density garden -style
apartments up to 24 dwelling units per acre.
HDR: garden apartments, urban garden apartments, 4-story wood
frame, and 4-over-1 podium construction up to 60 units per acre.
The table to the right includes recommendations for zoning code
changes that would allow these types of construction. Note that both
senior and non -senior housing should meet the same criteria in the HDR
zone.
Recommended Changes for MDR and HDR Zones
MDR
HDR
Maximum Density
Maximum Lot
Coverage
Maximum Height
24 du/ac
60% of gross land
area
35 ft (3 stories)
Upper Floor Step- None
Backs
Minimum Recreation
Space per Unit
Minimum Parking
No more than 160 SF
per unit
60 du/ac
75% of gross land
area
55 ft (5 stories)
10 ft from rear
setback line when
adjacent to LDR zone
No more than 160 SF
per unit
1 space per unit 1 space per unit
The City should allow administrative review for conforming structures
rather than requiring design review for housing in MDR and HDR zones.
In addition, structured parking should not be required in the URO.
Instead, the city can require that parking be located behind the
building and eliminate front setbacks to allow facades along the
sidewalk.
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
54
6)
Re -Opening Tukwila's MFTE Program Will Increase the
City's Regional Competitiveness
Neighboring cities that compete with Tukwila to attract development and which have demographics and market dynamics comparable to Tukwila's
offer tax exemptions for multifamily housing through the MFTE program. SeaTac, Burien, and Des Moines all offer eight -year tax abatements for
multifamily housing that meets city -specific criteria (outlined in the table below). SeaTac and Burien also offer twelve-year abatements for projects in
which 20% of units are affordable to low- and moderate -income households. Because rents are slightly lower in south King County than in other parts
of the metro area, there is less of a gap between market rate housing and housing targeted for tenants making 80% AMI. To attract more housing
development, Tukwila should consider expanding its recently re -instated MFTE program.
City
8-Year MFTE Requirements
12-Year MFTE Requirements
SeaTac
Burien
Des
Moines
• Located in designated residential target area
• At least 20 multifamily units
• Developed in a way that increases or preserves
property valuation
• Compliant with all zoning and land use requirements
• Located in designated residential target area
• Must not displace existing residential tenants
• At least 4 multifamily units
• 50% of space dedicated to permanent residential
occupancy
• Located in designated residential target area
• Limited to a total of 3,000 units (or 10 years after
approval date)
• Must further city goals & objectives for the Pacific
Ridge neighborhood
• Must be at least 50 feet in height with 60 residential
units
• Compliant with SeaTac Municipal Code
• Must be completed within 3 years of approval date
• Written agreement with the City
• Construction must be complete within 3 years of
approval
• Compliant with all City standards and guidelines
• Minimum density of 50 units per acre
• 50% of space dedicated to permanent residential
occupancy
• Property management required on -site 24/7
• Developed in a way that increases or preserves
property valuation
• Compliant with zoning code & land use regulations
• Must be completed within 3 years of approval date
• Same requirements at 8-year, AND
• 20% of multifamily housing units
must be affordable housing for low -
and moderate -income households
• Same requirements at 8-year, AND
• 20% of multifamily housing units
must be affordable housing for low -
and moderate -income households
• No 12 year program currently offered
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
55
Ensure that Local Building and Zoning Codes Allow for Novel
Housing Types
The MDR and HDR zones should allow for unconventional building types like point access
blocks, which are already legal in Seattle, and middle housing types like duplexes,
triplexes, fourplexes, six-plexes (vertical and side -by -side), and cottage clusters.
The side -by -side six-plex, shown in the drawing at the top right, was legalized in
Portland under the second phase of the Residential Infill Project. Its design was a
response to a survey of communities of color who expressed preferences for private
outdoor space and front doors as well as fewer stairs. In design, it is a two-story
townhome building turned sideways to fit on a residential lot. Allowing this type of
culturally responsive design in MDR and/or HDR zones would help expand the
diversity of housing options in Tukwila's residential neighborhoods.
The image on the bottom right shows the plan for the Riverview Cottages in Oregon City
— a prefabricated mass timber cottage cluster planned to be roughly 18 units per acre.
It provides a mix of private and community green spaces along with smaller -unit
detached housing. While Oregon City is less urban than Tukwila, there is room for this
type of housing in a more urban environment, as the Southard development proves.
However, the Southard is being built in the city's LDR zone through a development
agreement, rather than by -right. The City's code should explicitly legalize cottage
clusters in the MDR and HDR zones.
Finally, the City should legalize point access block/single staircase buildings. SB 5491
will allow adoption of Seattle's point access block code for cities with adequate fire
services starting in 2026. The City should ensure that its own building and zoning
codes are ready to adopt that change as soon as it is legal.
Illustration of a Side -by -Side Six-plex (Portland: Neighbors
Welcome)
r
P
Riverview Cottages, Oregon City (Aria Touch)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 56
Cf)
N
Extend the HDR Zone along Service Corridors like S 144th
Street
The Urban Renewal Overlay covers a relatively small area where NCC,
HDR, and MDR are the predominant zoning types. The URO runs along
Tukwila International Boulevard from 140th Street to 146th Street. The
amenities map compiled by LCG and shown at the top right, indicates
that there are a number of services along S 144th Street (the dashed blue
line on the maps to the right), where outside of the URO most of the
zoning is LDR. These services include:
Walgreens
Tukwila Library
Tukwila Village Farmer's Market
Foster High School
Tukwila Fire Station #54
Tukwila Pool
Showalter Middle School
Tukwila School District Administration Office
Extending the HDR zone along S 144th Street would enable more
households to access these crucial services on foot or bicycle rather than
by car.
Points of Interest Map, Zoomed to S 144th Street (LCG)
Mir12 Muni In 17676.
r�i �1 nR1
ll ram
Fit"
a � =y =!i C�
I, HMII. Ujila
,i„i
.■� a ii!I�■1� °-411111 —
64,
Education
Faith -Based Institution
Financial Services
Healthcare
Markets & Grocery
Parks & Community Centers
Public Services
Retail
Transportation
Tukwila Zoning Map Showing the Area around S 144th Street (city of Tukwila)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
57
LELAND CONSULTING GROUP
Peop e Places Prosperiy
503.222.1600
www.lelandconsulting.com
Strategic Advisors to Public and Private Development
Medium- and High -Density Zoning Analysis
Presentation ia the City Cour":il
P F"fARED FOR
City of Tukwila
NOVEMBER 2023
PREPARED BY
L LELAND CONSULTING GROUP
Purpose and Goals
Purpose
• Analyze Tukwila's zoning code, related policies,
and local demand for medium- and high -density
multifamily housing
Goals
Assist the City of Tukwila in updating the City's
Comprehensive Plan for the 2024- 2044 planning
horizon as required by the Growth Management
Act.
• Identify gaps related to PSRC, GMA and the
Countywide Planning Policy requirements.
eklummun
Tukwila Comprehensive Plan Medium- and High -Density Zoning Analysis
1
C)
6)
Zones to be Analyzed
MDR: Medium Density Residential
• Family and group residential uses
• Alternative to lower density family
residential housing and more
intensely developed group
residential housing and related
uses
HDR: High Density Residential
• High -density, multiple -family
compatible with commercial and
office
Zoning
High Density Residential
Medium Density Residential
Low Density Residential
Tukwila Comprehensive Plan Medium- and High -Density Zoning Analysis 2
Al.Categories of Key Findings
Zoning
Multifamily Tax Processes Demand
Exemption
(MFTE)
Recent Novel
Developments Housing Types
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
3
Recent Housing Development in Tukwila
New Multifamily Construction Since 2010 Has Largely Been
Built Near but Not In Tukwila
•
•
•
•
44 new multifamily buildings have been built in
South King County since 2010
Most of the new multifamily construction in this area
has taken place just outside Tukwila city limits in
Kent, Renton, and SeaTac
On average, these new multifamily buildings
have a density of 60 units per acre
Despite similar rents and construction costs, Tukwila
stands out as an area that is not realizing the full
benefit of investment into South King County
Recent Multifamily Developments in South King County (CoStar, LCG)
Housing Units
o ,0
0 100
0500
City Limits
® Sounder Commuter Rail
LINK Light Rail Station
Highways
Parks
0 2.500 5,000 Feet
0 0 05
.5 1 Miles
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 5
Five Housing Developments Have Been Completed in
Tukwila Since 2010
•
•
None of these projects could
be built under current code in
the MDR or HDR zones
Three of the projects utilized
development agreements to
bypass local zoning
requirements.
The Confluence
Tukwila Village Senior Living
Mariblu Southcenter
Hotel Interurban / Airmark Apartments
Holden Southcenter
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 6
None of the Multifamily Developments in Tukwila's Pipeline
Are in the MDR or HDR Zones
Site Rendering of The Southard Development (CoStar)
The Southard
• 18-unit cottage cluster / townhome
development on LDR site
Prose
285 units proposed on a 1.86-acre
TUC-TOD site
The Vintage
•
272 units of senior housing proposed
on 4.85 acres of land zoned LDR and
HDR 3118 S 140th Street, Tukwila, WA
Units/Acre 12.6
FAR 0.2
Construction Type Cottage Cluster / Parking None
Townhomes
Est. Completion Date 2024
Units 18
Tukwila Comprehensive Plan Medium- and High -Density Zoning Analysis
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Common Multifamily Prototypes in South King
County
Garden -Style Apartment Buildings in South King County
Miller Creek Court
215 S 162nd Street
Burien, WA
Year Built 2014 Units/Acre 21
Units 46 FAR 0.72
Avg. Unit Size 1,337 SF Parking Surface / Garage
Construction Type Townhomes Avg. Rent/SF $1.80
Astral Apartments
6329 S 212th Street
Kent, WA
Year Built 2023
Units 155
Avg. Unit Size 661
Construction Type Garden Style
Units/Acre 24
FAR 0.54
Parking Surface
Avg. Rent/SF $2.69
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
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Podium -Style Apartment Buildings in South King County
Viewpoint Apartment Homes
21428 International Boulevard S
SeaTac, WA
Year Built 2012 Units/Acre 60
Units 90 FAR 0.88
Avg. Unit Size 625 SF Parking Structured / Surface
Construction Type 4-over-1 Avg. Rent/SF $2.99
Altitude Apartments
1600 Benson Road S
Renton, WA
Year Built 2015
Units 120
Avg. Unit Size 987
Construction Type 4-over-1
Units/Acre 45
FAR 0.8
Parking Surface
Avg. Rent/SF $2.24
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
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Density and Rent Determine the Ability to Provide
Structured Parking in Podium Projects
Year Built
Units
Avg. Unit Size
Construction Type
Adriana Senior Apartments
22525 7th Avenue S
Des Moines, WA
2018
119
620 SF
5-Over-1
Units/Acre
FAR
Parking
Avg. Rent/SF
178
3.44
Structured
$2.64
Year Built
Units
Avg. Unit Size
Construction Type
2020
365
782
3-Over-1
Midtown 64
24615 64th Avenue S
Kent, WA
Units/Acre
FAR
Parking
Avg. Rent/SF
37
0.73
Surface & Structured
$2.60
Tukwila Comprehensive Plan Medium- and High -Density Zoning Analysis
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Aligning Zoning Code & Housing Goals
Major Challenges in the MDR and HDR Zones
Density
restrictions
Upper floor
step -backs
Maximum lot
coverage
requirements
Recreation
space
requirements
Minimum lot
area per unit
Parking
requirements
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 13
00
Minimum Lot Size per Unit and Upper Floor Step -Backs Limit
What Can Be Built in Tukwila's MDR Zone
The purpose of Tukwila's Medium Density Residential (MDR)
zone is:
To provide areas for family and group residential uses, and
[serve] as an alternative to lower density family residential
housing and more intensely developed group residential
housing and related uses. (18.12.010A)
Case Study: Renton Town homes
14.5 du/ac 15.9 du/ac
Step -backs required on all Top -floor front step -backs
sides of 2nd & 3rd stories only
Min. required lot area of 2,738 SF gross lot area per
3,000 SF per unit unit
Condo Townhomes at 1750 Lake Washington Boulevard N, Renton (CoStar)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
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Tukwila's Density Standards in HDR Zones Differ Widely for
Senior and Non -Senior Housing
The purpose of Tukwila's High Density Residential (HDR) zone is:
To provide a high -density, multiple -family district which is also compatible with
commercial and office areas. (18.14.010A)
Case Studies: Mill Creek Vista & Bristol at Southport
Tukwila HDR Zoning
Mill Creek Vista
Bristol at Southport
12 units; Built 1980
195 units; Built 2006
Upper floor step -backs No step -backs
required on all sides
No step -backs
Max density of 22 du/ac
(60 du/ac for senior
housing)
22 units per acre
60 units per acre
2,000 SF lot area per unit 1,997 SF lot area per unit 722 SF lot area per unit
Structured parking Surface parking
required in URO
Surface parking
Max height of 45 ft 27 ft
54 ft
Mill Creek Vista Apartments, Kent (Costar)
The Bristol at Southport, Renton (CoStar)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
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00
Maximum Lot Size Calculations Should Be Calculated from
Gross Land Area
•
•
•
Tukwila's zoning code (18.50.085)
requires that in MDR and HDR zones,
maximum developable area coverage is
50% of NET lot area
Recreational facilities, vehicle circulation
aisles, sidewalks, and paths are all
excluded from the lot coverage
calculation
Calculating lot coverage based on net
area is unconventional and
significantly limits development.
Example Lot Coverage for a 22-Unit Development on a 1-Acre Site
Tukwila Comprehensive Plan Medium- and High -Density Zoning Analysis 16
Tukwila Should Also Consider Changing Its Design Review
Requirements
Design review by Tukwila's Board of
Architectural Review (BAR) is required
for multifamily structures in the MDR
and HDR zones
These reviews increase the equity
needs of developers as well as
financial risk.
Amending the design review process to
an administrative process for most or all
projects would:
•
•
•
•
Reduce the time the process takes,
Increase certainty for developers,
Eliminate redundancies in staff
and BAR each conducting design
review, and
Standardize the process with state
requirements for smaller
residential projects
Tukwila Village Senior Living (CoStar)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
17
Recommendations
MDR and HDR Zones Should be Modified to Allow the Types
of Housing Most Common in South King County
•
•
•
•
Tukwila's zoning code changes
should begin with determining
what kinds of housing the City
wants to see
Both senior and non -senior
housing should meet the same
criteria in the HDR zone.
The City should allow
administrative review for
conforming structures
Structured parking should not
be required in the URO.
Maximum Density
24 du/ac
60 du/ac
Maximum Lot Coverage
60% of gross land area
75% of gross land area
Maximum Height
Upper Floor Step -Backs
Minimum Recreation
Space per Unit
Minimum Parking
35 ft (3 stories)
None
No more than 160 SF per
unit
1 space per unit
55 ft (5 stories)
10 ft from rear setback
line when adjacent to
LDR zone
No more than 160 SF per
unit
1 space per unit
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 19
CO
Re -Opening Tukwila's MFTE Program Will Increase the City's
Regional Competitiveness
Tukwila recently re -instated its 8-
and 12-year MFTE programs. The
City should consider expanding
these programs beyond the
current zones to help attract
development.
The Polaris at SeaTac used the MFTE Program
2022 HUD Maximum Rents for Regulated Affordable Housing & Tukwila Market Rent by Unit Size
Unit Size
30% 40% 50% 60% 70% 80%
Studio
1-Bed
2-Bed
3-Bed
$680
$728
$873
$1,009
$906
$971
$1,165
$1,346
$1,132
$1,213
$1,456
$1,682
$1,359 $1,585
$1,456 $1,699
$1,747 $2,038
imh$2,019_ $2,355
Sources: US Department of Housing and Urban Development; CoStar
$1,668
$1,787
$2,145
$2,478
Mkt Rent
$1,322
$1,348
$1,680
$1,945
Tukwila Comprehensive Plan Medium- and High -Density Zoning Analysis 20
Middle Housing Could Provide an Opportunity for Gentle
Density in LDR and MDR Zones
Middle housing could potentially help Tukwila increase its Tukwila should allow middle housing at a higher density
housing supply in lower -density zones while mitigating than is required under HB 1110, especially in the city's LDR
displacement. and MDR zones
Portland Residential Infill: Lots & Demolitions vs. Number of Units Permitted Missing Middle Housing Typologies (Opticos)
(City of Portland)
300
200
0
102
lots
Total Lots • Demolished Units Constructed Unlls
24 ikpmas
1.2:1
126
units
House, House w/ADU*
81
lots
46 heuaes
.J.. ! � �� ty�•tI
! C t ge Medum Ste iked Work \\
Cou ty d —
'- Duplex. F pl x: ourtyar — — — — IVO Rise
SideBySide. Stacked —
\ stacked _Courtyard
Missing Middle Housing
271
units
Duplex, Triplex, Fourplex"
Detached Single -Family
Houses
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 21
CO
O7
Ensure that Local Building and Zoning Codes Allow for Novel
Housing Types
Illustration of a Side -by -Side Six-plex (Portland:
Neighbors Welcome)
Riverview Cottages, Oregon City (Aria Touch)
Point Access Block in West Hollywood
(Auckland Design Manual)
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
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Extend the HDR Zone along Service Corridors like S 14491
Street
Points of Interest Map, Zoomed to S 144th Street (LCG)
Education
Faith -Based Institution
Financial Services
Healthcare
Markets & Grocery
Parks & Community Centers
Public Services
Retail
Transportation
Tukwila Zoning Map Showing the Area around S 144th Street (city of Tukwila)
1
1111 w..�w
o r � E ._ 51l e.
a■�f;�I�1• 11 _
~
_...._.__ 911 • lip► Iiiilli=1iiiE1+
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis
23
CO
00
Thank you!
Questions?
Tukwila Comprehensive Plan I Medium- and High -Density Zoning Analysis 24
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