HomeMy WebLinkAboutCity Council Committees - Land Use and Planning Board - 06/22/2015 ECONOMIC & COMMUNITY DEVELOPMENT
Ben Wolters, Director
PLANNING DIVISION
Charlene Anderson, AICP, Planning Manager
KENT XFNS
Phone: 253-856-5454
Fax: 253-856-6454
220 Fourth Avenue S.
Kent, WA 98032-5895
LAND USE & PLANNING BOARD
WORKSHOP AGENDA
JUNE 22, 2015
7:00 PM
BOARD MEMBERS: Randall Smith, Chair; Barbara Phillips, Vice Chair; Frank
Cornelius; Navdeep Gill; Katherine Jones; Jack Ottini and Binoy Varughese
CITY STAFF: Planning Services: Charlene Anderson, Planning Manager; Hayley
Bonsteel, Planner/GIS Coordinator
This is to notify you that the Land Use and Planning Board will hold a Workshop on
MONDAY, JUNE 22, 2015 at 7:00 P.M. The workshop will be held in Kent City
Hall, City Council Chambers, 220 Fourth Avenue S, Kent, WA.
No public testimony is taken at LUPB workshops; however, the public is welcome to
attend. The workshop agenda includes the following item(s):
1. Accessory Dwellina Unit Zonina Code Amendment
General Discussion — Hayley Bonsteel
For documents pertaining to the Land Use and Planning Board, access the Co's website at:
h tti):Ilken twa.ic7m2.com/citizensIDefau/L ast)x?Departmen tlD=1004.
Any person requiring a disability accommodation should contact the City Clerk's Office in advance
at (253) 856-5725. For TTy/TDD service call the Washington Telecommunications Relay Service at
(800) 833-6388. For general information, contact Economic & Community Development
Department, Planning Division at(253) 856-5454.
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ECONOMIC & COMMUNITY DEVELOPMENT
Ben Wolters, Director
PLANNING DIVISION
Charlene Anderson, AICP, Planning Manager
KENT XFNS
Phone: 253-856-5454
Fax: 253-856-6454
220 Fourth Avenue S.
Kent, WA 98032-5895
June 11, 2015
TO: Chair Randall Smith and Land Use & Planning Board Members
FROM: Hayley Bonsteel, Planner & GIS Coordinator
RE: Accessory Dwelling Unit Zoning Code Amendment
For June 22, 2015 Workshop
SUMMARY:
At the June 81h 2015 Economic and Community Development Committee meeting,
staff received direction to explore broadly the City's accessory dwelling unit
standards and related regulations. At the June 22nd Land Use and Planning Board
workshop, staff will discuss the current code, local examples, and next steps to
both address the zoning code amendment request as well as the broader issues
regarding accessory structures.
BACKGROUND:
Docket #DKT-2014-1 requested a zoning code amendment for ADUs because the
current application of ADU regulations does not allow a detached garage and
detached ADU to be in the same structure without significant size restriction. There
is also a larger issue of standards managing accessory structures on residential lots
and staff will be analyzing a variety of possible actions as well as surveying existing
ADU homeowners. Staff will be available at the June 22nd workshop to discuss the
project.
See attached report.
HB:ah S:\Permit\Plan\ZONING—CODE AMENDMENT5\2015\ZCA-2015-3 Accessory Dwelling Units\06-08-
15_ECDC_Memo.doc
Encl: Accessory Dwelling Unit Standards and Site Coverage Analysis Report
cc: Charlene Anderson,AICP, Planning Manager
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Accessory Dwelling Unit Standards and
Site Coverage Analysis Report
"a tie Araentiraen Ek0 nr ea P^ -e; ax on Df«"d'..2014 1
Zoning Code Amendment Request
This zoning code amendment request was made because the current application of ADU regulations
does not allow a detached garage and detached ADU to be in the same structure without significant size
restriction.The request pointed out a logical discrepancy between part of the code and the current
application of the code: the code stipulates a maximum size for a detached ADU (800 square feet or 33%
of the size of the principal unit, whichever is smaller) but the current application dictates that the square
footage of the ADU be counted by including any square footage of a garage or accessory structure the
detached ADU is built into.This application therefore allows a detached ADU to be built freestanding at
the maximum size adjacent to a detached garage, but if the owner wanted to combine those structures
on one footprint and renovate the detached garage to include the ADU,there would be a limiting size
restriction (depending on the size of the garage).
The Broader Issue of Site Coverage and Accessory "structures
This code amendment request illuminates the need to reassess the City's accessory dwelling standards
and maximum site coverage standards.The City of Kent allows many types and sizes of accessory
buildings with several standards limiting the bulk of buildings.Accessory structures are defined as a
structure on the same lot with,and of a nature customarily and subordinate to,the principal structure.
Guest cottages, sheds, garages, and workshops are examples of typical accessory structures often found
in rear yards, as well as attached or detached Accessory Dwelling Units (ADUs).The above issue is
complicated by the fact that the zoning code allows garages to be sized up to 1,000 square feet for the
area where motor vehicles are stored or kept, but the building itself could be larger if the rest of the
building is not used for motor vehicles.
Go31lls
The City Zoning Code lists the goals of ADUs thus:
1.To increase the supply of affordable rental units through better use of the existing housing
stock, much of which is under-utilized because the baby boom has been followed by an empty
nester boom, because there are fewer children per family, because there are more single parent
households,and because there are more one (1) and two (2) person elderly households.
2.To make homeownership more affordable because it will be easier to buy both new and
existing homes with the help of an accessory apartment.
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3.To make it more comfortable for older people to retain their homes because an accessory
apartment can provide them with added income,security,companionship,and the opportunity
to trade rent reductions for needed services.
4.To make it easier for single parents to meet mortgage payments and hold onto their homes in
the wake of a divorce and,as a result, keep their children in the same neighborhood.
5.To increase the opportunity for disabled persons to live independently because accessory
units can provide them with both privacy and the proximity to needed support.
6.To reduce the isolation of households that is a result of increased affluence in housing,and/or
longer lifespans and periods of frailty,and/or suburban land use patterns that isolate people
who cannot drive.
7.To make better use of existing public investment in streets, transit, water, sewer, and other
utilities.
ECD staff also have the following broader goals in relation to these standards:
• Maintain neighborhood look and feel through regulations that manage bulk and protect views.
• Ensure regulations are sensible,complete,and effective without unnecessary complication.
Background on ADUs
Washington State Law requires cities with a population over 20,000 to incorporate ADU regulations into
city code (as per RCW 43.63A.215 and RCW 36.70A.400). ADUs are becoming increasingly popular as
cities strive to house growing populations in creative ways. ADUs are a form of small-scale infill
development.The real benefit to ADUs is that they are a style of housing that complements single-
family residential areas, and capitalize on existing housing stock. ADUs provide a source of income,
flexibility and creative living solutions for the changing demographics of our cities.ADUs generally
require the property owner to either reside in the ADU itself or in the primary residence,ensuring
accountability.
Our regulations currently allow attached and detached ADUs in all single-family residential zones and in
single-family dwellings within the City. If an ADU is constructed in a new single-family home, it is limited
to 40%of the principal unit.The size of a detached ADU (for either new construction or an existing
home) is limited to 800 square feet or 33%of the size of the principal unit,whichever is smaller.
Additionally,there are code provisions for converting structures that were existing at the time of
adoption of the ADU code,with limitations (e.g., up to 50%of the size of the principal unit).
According to anecdotal evidence from City of Kent current planning staff,there are not many ADUs in
the City of Kent, and the most common barrier to the construction of ADUs is the associated cost. Most
homeowners are dissuaded from considering, planning or building ADUs by the high cost of school
district and traffic impact fees.These fees can be as much as half the planned construction budget
($7,000-$8,000).These fees may be the main disincentive to ADU construction, and may also be
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negatively impacting the City's ability to meet the goals outlined above. However,ADUs for seniors may
be more practical because they are exempt from school impact fees provided there is a restriction
precluding school aged children as residents in the ADU.
ADU Standards and Prograins
ADU standards vary from jurisdiction to jurisdiction. Cities may choose to require one or more parking
spaces for ADUs, have specific height limits for accessory structures, or stipulate design standards to
ensure ADUs match the neighborhood character. Seattle has several reports and resources available
detailing the standards,options and results of its ADU program (called Backyard Cottages or BYCs in
Seattle when not built within the primary residence). Seattle provides resources for homeowners
considering their own BYC, including a building guide. Seattle, unlike the other jurisdictions surveyed,
limits the size of ADUs further when built into a detached garage, as Kent does—however, city planners
in Seattle have confirmed that this standard is under consideration for revision.
The approach of providing resources that help streamline the ADU process in Seattle is similar to a more
extensive ADU program in Santa Cruz, California. Santa Crui s ADU Development Program greatly assists
homeowners considering building an ADU on their property. Included in the program are an ADU Plan
Sets Book containing seven ADU prototype concepts designed by local and regional architects and
an ADU Manual containing a step-by-step guide on how to plan, design and obtain permits for an ADU.
The program included community outreach and advertisement, funded by a 3-year Sustainable
Communities grant,and the results show the effectiveness of the program.After relaxing the parking
requirements, implementing a low-interest ADU loan program for those agreeing to rent their ADU at
low-income prices, and the development of the streamlined architectural plan-set and manual,there
was a 300%increase in permits issued.This fit in with the City's goals to rapidly address a housing cost
crisis by providing more affordable housing.
In Portland, Oregon, the removal of disincentives also led to an increase in ADU construction. Portland
requires no parking for ADUs, and in 1998 repealed the owner occupancy requirement in an attempt to
encourage ADU development. Contrary to common fears, there was no evidence of an explosion of ADU
development. Instead,a steady, manageable stream of ADU construction has caused Portland to now
have a variety of unique and creative dwelling units providing more density within low-rise
developments.
Managing Ruimllllllm
The most common fears regarding ADUs seem to center on the appearance of too much "bulk" in a low
density area. It's important to remember that there are many factors that may affect the appearance of
"bulk."
• Height of structures
• Volume of structures
• Space between structures (density of buildings)
• Size of lot (smaller lot=structures seem larger)
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• Orientation of structures(narrow,deep structures appear less bulky than wide structures of
same volume)
• Materiality of structures (and number of windows)
• Whether space between structures has vegetation, is open, paved,etc.
• Neighboring bulk
M:awmdards.Affe(Aing HinlIlllll
The standards most likely to limit bulk are maximum site coverage standards,accessory building
coverage standards and accessory building height standards.
Maximum site coverage in Kent is defined as that portion of a lot covered by buildings or structures.
Currently, the maximum site coverage allowed in Kent ranges from 30%-55%for residential areas,which
is similar to other jurisdictions (see Table 1).
Table 1.
20% 65%
50% 60%
20,OOOsf or more: 4,500sf+7.5%of lot area Less than 3000sf: 50%of lot area.
over 20,OOOsf. 3,OOOsf-4,999sf: 1500sf+ 37.5%of lot area
5,OOOsf-19,999sf: 2,250 sf+ 15%of lot area over 3,OOOsf
over S,OOOsf
35% 1000sf+ 15% lot area
35% 50%
None None
35% 50%
35% 35%
35% 40%
35% 35%
25% 50%
30% 55%
*Federal Way and Tukwila count all impervious surfaces towards their site coverage—not just
houses and accessory buildings, but paths, driveways, patios, etc. Most cities(including Kent)
limit impervious surface with a different standard. For instance, a single family lot in Renton
zoned R-6 has a maximum building coverage of 40%but a maximum impervious surface
coverage of 55% (see table 2). In Kent,a lot of similar size would be zoned SR-4.5 and have a
maximum allowed site coverage of 45%with a maximum impervious surface coverage of 60%. In
Federal Way,there is a single standard limiting all impervious surface including buildings,and
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for the same lot size as in the above examples,the maximum lot coverage (buildings and all
impervious surfaces) is 60%.
The accessory building coverage standard is another standard which may limit bulk of accessory
buildings. Of the jurisdictions reviewed, fewer than half contained an accessory building coverage
standard.The accessory building coverage standard in Kent only applies when there is a guest house on
the property.The standard states that "a guesthouse,together with other accessory buildings, shall not
exceed 30%of the area of the rear yard on which it is built." See Table 2 for accessory building coverage
standards in local jurisdictions.
Table 2.
The lot coverage of the primary residential structure combined with all accessory
buildings shall not exceed the maximum lot coverage of the Zoning District.
none
Combined building coverage of all detached accessory structures not to exceed 15%
of total area of site.
A detached accessory dwelling unit, together with any other accessory structures and
other portions of the principal structure, is limited to a maximum combined coverage
of 40 percent of the rear yard.The combined building coverage of all detached
accessory structures may not exceed 15%of the total area of the site.
none
Total square footage of all accessory building footprints can be no more than 15%of
the square footage of the lot.
none
Accessory buildings and structures within residential zone classifications, including
but not limited to storage buildings and detached private garages... shall cover a
maximum of 5%of the lot area,and shall have an exterior height no greater than 20
feet or the height of the primary building or structure,whichever is less.
Detached accessory structures are limited to a maximum lot coverage of 10 percent
except as otherwise provided.The 10 percent maximum lot coverage applicable to
detached accessory structures located on lots less than 20,000 square feet can be
exceeded provided a written mutual agreement of all abutting property owners is
recorded with the King County Division of Records and Elections and filed with the
City Clerk. However,the requirements for maximum lot coverage by structures ...
shall not be exceeded.
none
none
There shall be not more than one (1) guesthouse on any one (1) building site,which,
together with other accessory buildings,shall not exceed thirty (30) percent of the
area of the rear yard on which it is built.
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Some jurisdictions limit the height of accessory structures.See Table 3 for accessory height limits in local
jurisdictions.
Table 3.
30' but not taller than primary.
30'
18'
12-16' plus roof,depending on width of lot
None
15' generally, 25' with stipulations
30'-45'
20' or height of primary structure,whichever is less
15' unless all abutting property owners mutually agree
Same as primary structure
16-35'
Same as primary structure
Occasionally,jurisdictions will require a certain amount of rear or usable yard space as an alternative
way of preserving the open character of a residential area.This standard could simply be another
calculation homeowners must do in planning their ADU (a hoop to jump through), or it could effectively
supplement the maximum site coverage standards in a way that is more explicitly about rear yard space.
Tacoma has no maximum site coverage standards, and instead has a maximum accessory building
coverage standard (15%of lot) alongside a minimum usable yard space standard:
"All lots shall provide a contiguous rear or side usable yard space equivalent to at least 10%of
the lot size.This usable yard space shall meet the following standards: (1) Have no dimension
less than 15-feet,except for lots that are less than 3,500 square feet, where the minimum
dimension shall be no less than 12 feet. (2) Not include structures, parking,alley or driveway
spaces or required critical area buffers." (Tacoma Municipal Code 13.06.100)
This approach is more focused on the outcome of usable yard space.
To understand how the regulations might play out,graphics renderings can help conceptualize ADU
massing differences between various jurisdictions.To accurately compare the complex set of standards,
an example lot with the following dimensions was used as a baseline:
• Lot size: 7,980 square feet
• Lot width: 60 feet
• Lot depth: 133 feet
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• Baseline structures on lot:
o House: 1,222 square feet footprint (1900 square feet of living space)
o Detached garage: 576 square feet (two parking spaces)
o Small shed: 27 square feet
• Configuration of lot (see Renderings 1-3):
o House set back 20 feet from front lot line
o Side yards each 10 feet wide
o Path from side entrance of house to detached garage (202 square feet)
The three renderings below show the base lot configuration (from three different views).
Rendering 1.
Rendering 2.
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If the homeowner for this lot wished to create an ADU at its biggest possible size,the following series of
images conceptually show the visual bulk potential based on the standards for each jurisdiction and
whether the ADU is attached, detached and freestanding,or detached but in the same structure as the
garage. In most cases shown below,the example lot with ADU is nowhere near the maximum site
coverage allowed in that city,and the homeowner would have the option of adding more non-habitable
accessory spaces (such as workshops,etc.)—however, this is not shown as (a) it is unlikely and (b) there
are many complicating factors regarding arrangement of various structures on a lot.
AUam:ilina',rv,d
In this example,one can see the bulk of an addition that is somewhat built into the structure of the
house but does not decrease the square footage of livable space in the house.
Renderings 4-7 show attached ADUs at a likely maximum size given each jurisdiction's standards(from
different views). Most lots look quite similar, as the standards for attached ADUs are fairly similar,
although Auburn's larger size maximums makes for a slightly bulkier result on that lot.Tukwila's higher
parking requirement also stands out,with two spaces added instead of one.The Kent example lot shows
an ADU at about 627 square feet,which is 33%of the living space of the primary residence. Since this
number is less than 800 square feet, it is the maximum to which a Kent homeowner would be able to
build the ADU.
These renderings show that Kent allows similar amounts of bulk to other jurisdictions in its attached
ADU standards. Note that Tacoma's rear yard space requirement required moving the shed closer to the
ADU to allow for the full rear yard dimensions required.
Rendering 4.
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Detached ADUs are not permitted in Bellevue, Bothell or Tukwila,so those lots are shown without any
ADUs in the renderings below.Tacoma allows detached ADUs in higher single-family density zones, but
only attached ADUs at the size of the example lot,so that lot is also shown without any ADU in
Renderings 8-11. Seattle's height limit of 16' (plus roof pitch) makes for slightly less bulk on that lot, but
otherwise the lots with ADUs look pretty similar. All ADUs shown below are between 627 and 950
square feet.
Rendering 8.
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Again, Bothell, Bellevue and Tukwila do not allow detached ADUs at all,and Tacoma only allows them at
higher single-family densities,so all four are shown without ADUs in the below renderings. Kent and
Seattle both count garage space as part of the ADU square footage when in the same structure, so the
potential ADU bulk is much lower for these two lots.
Rendering 12.
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V!I!ew from N ell g1hIlIlboriun 1l'mmw°dIh DO adhmKKd mmiffi Gam°ge
From the porch across the street,one can see more bulk behind the house on the Portland lot, whereas
the smaller ADU size behind the house on the Kent lot is barely visible.
Rendering 16.
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Attached ADUs are hardly visible from the porch across the street.
Rendering 18.
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Freestanding detached ADUs are somewhat more visible, particularly if they are built to the maximum
allowable height (which is the height of the primary structure in Kent).
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Rendering 19.
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According to the above graphical comparisons, Kent has mostly comparable bulk allowance standards to
other jurisdictions. Requiring the garage floor area to be counted as part of the ADU when built into the
garage limits the appearance of bulk in that type of arrangement—however, most jurisdictions do not
require the structure to be counted this way, and it is not the most effective means to limiting bulk in
Kent (given the higher maximum size of a detached ADU separate from a garage).
Next steps„
To better achieve Kent's goals with regards to ADUs, staff is pursuing a work program to analyze the
actions below.
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Actions under Background Summary
consideration
Resolve square The square footage calculation application This code amendment would
footage calculation was the original topic of the zoning code allow the square footage of an
application. amendment request.Current application of ADU to be counted separately
zoning regulations requires square footage of from the accessory structure
garage or accessory structure to be counted footprint if combined.
towards ADU square footage maximum if
built in the same structure.This limits the
size of the possible ADU if it is built on same
footprint (or part of same structure).
Resolve accessory Kent regulations stipulate that guest houses, This code amendment would
coverage when combined with other accessory require that the accessory
application. structures, cannot cover more than 30%of building coverage standard for
the rear yard—but the regulation only guest houses apply to all
applies if there is a guest house. If no guest accessory structures.
house is present, accessory structures may
cover as much of the rear yard as desired,as
long as maximum site coverage and
maximum impervious surface coverage
requirements are met.
Introduce Jurisdictions such as Portland, Seattle, This additional language would
maximum height Auburn and Tacoma have a maximum height limit the height of all accessory
standard. standard for accessory structures. Kent structures.
allows accessory structures to be any height
as long as they don't exceed the height limits
of the zoning district.
Introduce rear yard Rear yard space standards are less common, This additional language would
space standard. but are another form of regulation which can set a minimum size of"useable"
manage accessory structure coverage. Rear rear yard space for the lot, based
yard space standards require an open area of on a percentage of the total lot
a certain size that is not covered by size or minimum dimensions.
structures or surfaces (patios, walkways,etc.)
Tacoma is one local example of a jurisdiction
that has a useable rear yard space standard.
Conduct survey of There are a handful of constructed ADUs in The objective of a survey of ADU
ADU homeowners Kent but staff does not have a homeowners or permit applicants
or those who have comprehensive understanding of the barriers would be to find out what the
applied for ADU to constructing them, how existing ADUs are opportunities and barriers have
permits. being used, how city regulations may have been for ADU construction in
impeded or aided homeowners interested in Kent.The results of the survey
ADUs in the past, etc. ADUs are also subject may inform a promotional or
to traffic and school impact fees, and the incentivizing program.
effect of these fees on the feasibility of
constructing an ADU is not well understood
by staff.
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Pursuing these strategies could help the City of Kent more proactively encourage flexible housing option
development. More ADUs in Kent could allow single-family neighborhoods and residences to take on
more of our growing population without sacrificing character.