Mercer Island prides itself on being a residential community. As such, most of the Island’s approximately 6.2 square miles of land area is developed with single family homes. The Island is served by a small Town Center and two other commercial zones which focus on the needs of the local population. Mixed-use and multifamily developments are located within the Town Center. Multifamily development also rings the Town Center and the western fringe of the smaller Commercial Office Zone.

Parks, open spaces, educational and recreational opportunities are highly valued and consume a large amount of land. The Island has 472 acres of park and open space lands including small neighborhood parks and trails as well as several larger recreational areas, including Luther Burbank Park and Aubrey Davis Park above the Interstate 90 tunnel. One hundred and fifteen acres of natural-forested land are set aside in Pioneer Park and an additional 150 acres of public open spaces are scattered across the community. There are four elementary schools (one scheduled to open in fall 2016), one middle school and a high school owned and operated by the Mercer Island School District. In addition, there are several private schools at the elementary and secondary education levels.

The community strongly values environmental protection. As a result, local development regulations have sought to safeguard land, water and the natural environment, balanced with private property rights. To reflect community priorities, development regulations also attempt to balance views and tree conservation.

For many years, Mercer Island citizens have been concerned about the future of the community’s downtown. Past business district revitalization initiatives (e.g. Project Renaissance in 1990) strove to overcome the effects of “under-capitalization” in the Town Center. These efforts sought to support and revitalize downtown commercial/retail businesses and devised a number of recommendations for future Town Center redevelopment. Growing out of previous planning efforts, a renewed interest in Town Center revitalization emerged in 1992 -- one looking to turn the 33-year-old downtown into the vital economic and social center of the community.

In 1992 the City of Mercer Island undertook a major “citizen visioning” process that culminated in a broad new vision and direction for future Town Center development as presented in a document entitled “Town Center Plan for the City of Mercer Island”, dated November 30, 1994. The City used an outside consultant to help lead a five-day citizen design charrette involving hundreds of Island residents and design professionals. This citizen vision became the foundation for new design and development standards within the Town Center and a major part of the new Comprehensive Plan that was adopted in the fall of 1994. At the same time, the City invested about $5 million in street and streetscape improvements to create a central pedestrian street, along 78th Avenue and route the majority of vehicular trips around the core downtown onto 77th and 80th Avenues. Specific new design and development standards to implement the Town Center vision were adopted in December of 1995. The Mercer Island Design Commission, City staff and citizens used these standards to review all Town Center projects until 2002.

In 2002, the City undertook a major planning effort to review and modify Town Center design and development guidelines, based on knowledge and experience gained from the previous seven years. Several changes were made in the existing development and design standards to promote public-private partnerships, strengthen parking standards, and develop public spaces as part of private development. Another goal of the revised standards was to unify the major focal points of the Town Center including the pedestrian streetscape of 78th Avenue, an expanded Park-and-Ride and Transit Facility, the public sculpture garden, and the Mercerdale Park facility. As a result, the following changes were made to the design standards:

Expanding sidewalk widths along the pedestrian spine of 78th Avenue between Mercerdale Park on the south and the Sculpture Garden Park on the north;

Identifying opportunity sites at the north end of 78th for increased public spaces;

Requiring that new projects include additional public amenities in exchange for increased building height above the two-story minimum; and

Increasing the number of visual interest design features required at the street level to achieve pedestrian scale.

The changes to the design and development standards were formulated by a seven-member Ad Hoc Committee composed of citizen architects, engineers, planners and several elected officials. Working for three months, the Ad Hoc Committee forwarded its recommendations to the Planning Commission, Design Commission and City Council for review. The revised Town Center Development and Design Standards (Mercer Island City Code Chapter 19.11) were adopted by City Council in July 2002 and amended in June 2016. They will continue to implement the Town Center vision.

The effects of the City’s efforts to focus growth and revitalize the Town Center through targeted capital improvements, development incentives and design standards to foster high quality development are now materializing.

Between 2001 and 2007, 510 new housing units, and 115,922 square feet of commercial area were constructed in the Town Center. Between 2007 and August 2014, 360 new housing units, and 218,015 square feet of new commercial area were constructed.

In 2014, the City began a process to review the vision, Comprehensive Plan polices and development and design guidelines for the Town Center. This effort involved several stakeholder groups, 15 joint meetings of the Planning and Design Commissions and hundreds of public comments.

During 2004, the City engaged in a major effort to develop new design standards for all non-single family development in zoning districts outside the Town Center. This effort also used an Ad-Hoc process of elected officials, design commissioners, developers, and architects. The design standards for Zones Outside of Town Center were adopted in December 2004. These standards provide new direction for quality design of non-residential structures in residential zones and other multi-family, commercial, office and public zones outside the Town Center.

Updates to this document were made in 2014 to comply with the Countywide Planning Policies, including updated housing and employment targets.

In 2006, a grassroots effort of Island citizens led the City to modify the vision statement in its comprehensive plan to include language embracing general sustainability, and in May 2007 the Council committed to a sustainability work program as well as a specific climate goal of reducing greenhouse gas emissions by 80% from 2007 levels by 2050, which was consistent with King County and Washington State targets. Later in 2007, the Council set an interim emissions reduction goal (often called a “milepost”) for City operations of 5% by 2012.

From 2010 to 2014, with the entire community’s sustainability in mind, the City has implemented a wide range of outreach programs, efficiency campaigns, alternative energy initiatives, land-use guidelines, and other natural resource management measures designed to minimize the overall impacts generated by Island residents, for the benefit of future generations. Due to the 20-year horizon envisioned by this comprehensive plan, it is especially appropriate to include measures that address the long-term actions needed to reduce greenhouse gas emissions, ideally in collaboration with other local governments. Actions that the City will take in the management of its own facilities and operations are addressed in the Capital Facilities Element of this plan.

These measures, and others under consideration, are identified in more detail in a rolling 6-year Sustainability Plan, to be adopted in 2016, which will guide the City’s internal and external actions while taking into account the interrelated issues of climate change, population change, land use, public infrastructure, natural resources management, quality of life, public health, and economic development.


Town Center

The Town Center is a 76-acre bowl-shaped area that includes residential, retail, commercial, mixed-use and office-oriented businesses. Historically, convenience businesses -- groceries, drugstores, service stations, dry cleaners, and banks -- have dominated the commercial land uses; many of them belonging to larger regional or national chains. Retailers and other commercial services are scattered throughout the Town Center and are not concentrated in any particular area. With a diffused development pattern, the Town Center is not conducive to “browsing”, making movement around the downtown difficult and inconvenient for pedestrians, physically disadvantaged persons and bicyclists.

Mercer Island’s downtown is located only 3 miles from Seattle and 1 mile from Bellevue via I-90. I-90 currently provides critical vehicular, bicycle and pedestrian access to the Town Center as well as the rest of the Island. Regional transportation plans anticipate future development of a high capacity transit system in the I-90 corridor. In light of recent and potential future public transportation investments in the I-90 corridor and in keeping with the region’s emerging growth philosophy, redevelopment and moderate concentration of future growth into Mercer Island’s Town Center represents the wisest and most efficient use of the transportation infrastructure.

As required by the Growth Management Act of 1990, the Land Use Element presents a practical and balanced set of policies that address current and future land use issues. An inventory of existing land uses (Table 1) and a forecast of future development and population trends (Section III.) provide a backdrop for issues and policies. Subsequent sections IV and V address major land use issues and policies for the Town Center and non-Town Center areas.

Table 1. Town Center Land Uses & Facts Snapshot (May 2015)

Total Land Area

76.5 acres

Total Net Land Area (excludes public right-of-way)

61.1 acres

Total Floor Area (includes all uses)

2,385,723 square feet (20% office, 15% retail, and 65% residential)

Total Floor Area – Ratio


Total Housing Units


Total Net Residential Density

25 units/acre (Approx. 75 units/acre on sites with residential uses)

Total Employment


Notes: This table includes one mixed-use project currently under construction as of May 2015 (i.e. Hadley).

1This information is provided by the PSRC and is derived from Census data.

Areas Outside the Town Center

Single family residential zoning accounts for 88% of the Island’s land use. There are 3,534 acres zoned for single family residential development. This compares to 77 acres in the Town Center zones, 19 acres for Commercial Office zone, and 103 acres in multi-family zones (Table 2). City Hall is located in a Commercial Office zone, while other key civic buildings such as the Post Office and the Main Fire Station are located in the Town Center and City Hall. Many of the remaining public buildings, schools, recreational facilities and places of religious worship are located in residential or public zones.


Table 2. Land Use Zones and Acreage (2014)



Business - B


Commercial Office - CO


Multifamily - MF-2


Multifamily - MF-2L


Multifamily - MF-3


Public Institution - P


Planned Business - PBZ


Single Family - R-12


Single Family - R-15


Single Family - R-8.4


Single Family - R-9.6


Town Center - TC


Note: Figures above include adjacent right-of-way.

Approximately 95% of all residential land on Mercer Island is currently developed. Over the last thirty years, most public facilities have been re-constructed, or have planned additions, in sufficient quantities to serve current and projected populations. This category includes schools, parks and recreation facilities, streets and arterials, and fire stations. Future re-investments in these facilities will primarily improve the reliability and function of the community’s “infrastructure” rather than adding significant new capacity. [Refer to the Capital Facilities Element for a more in-depth discussion of public facilities.]

Single family residential zones designate a number of different lot sizes and densities including 8,400 sq. ft., 9,600 sq. ft., 12,000 sq. ft. and 15,000 sq. ft. Of the 3,534 acres in these zones, approximately 145 remain unimproved. Most unimproved lots are small parcels and/or are platted building lots within previously developed neighborhoods. Some additional capacity exists in larger lots which can be subdivided. However, during the planning horizon, the City expects an average of roughly six subdivisions a year, the majority of which will be short plats of four or fewer lots.

The most densely developed neighborhoods are found on the Island’s north end. This includes East Seattle and First Hill as well as neighborhoods immediately north and south of the I-90 corridor and areas along the entire length of Island Crest Way.

The least densely populated neighborhoods are ones with the largest minimum lot size and are designated as Zone R-15 (15,000 sq. ft. minimum lot size). These neighborhoods, generally located along East and West Mercer Way, contain the greatest amount of undeveloped residential land and often contain extremely steep slopes, deep and narrow ravines and small watercourses. Because environmentally sensitive areas often require careful development and engineering techniques, many of these undeveloped lands are difficult and expensive to develop.

Generally, Mercer Island’s oldest neighborhoods are situated on a fairly regular street grid with homes built on comparatively small lots 40 to 60 years ago. Interspersed among the older homes are renovated homes and new homes that are often noticeably larger. Newer developments tend to consist of large homes on steeply pitched, irregular lots, with winding narrow private roads and driveways. Many residential areas of Mercer Island are characterized by large mature tree cover. Preservation of this greenery is an important community value.

Most Mercer Island multi-family housing is located in or on the borders of the Town Center. However, two very large complexes straddle I-90 and are adjacent to single family areas. Shorewood Apartments is an older, stable development of 646 apartment units. It was extensively remodeled in 2000. North of Shorewood and across I-90 is the retirement community of Covenant Shores. This development has a total of 237 living units, ranging from independent living to fully assisted living.

There is one Commercial/Office (CO) zone outside the Town Center. It is located along the south side of the I-90 corridor at East Mercer Way and contains several office buildings, including the Mercer Island City Hall. In the summer of 2004, the regulations in the CO zone were amended to add retirement homes as a permitted use with conditions.

For land use and transportation planning purposes, Mercer Island has not been designated as an Urban Center in the Puget Sound Regional Council’s Vision 2020. As such, Mercer Island will not share in the major growth of the region, but will continue to see new employment and residential development, most of which will be concentrated in the Town Center. Employment will continue to grow slowly and will be significantly oriented towards serving the local residential community. Transit service will focus on connecting the Island to other metropolitan and sub-regional centers via Interstate 90 and the region’s high capacity transit system.


Residential and Employment 20-year Growth Targets

The King County Countywide Planning Policies (CPPs) establish growth targets for all of the jurisdictions within King County. The CPPs were initially adopted in 1992, and have been amended several times since then. Elected officials from King County, the Cities of Seattle and Bellevue, and the Sound Cities Association meet as the Growth Management Planning Council (GMPC). This Council makes recommendations to the County Council, which has the authority to adopt and amend the CPPs. During 2012, the GMPC worked with an inter-jurisdictional team of King County Planning Directors to determine an equitable distribution of the growth targets throughout the County. It was agreed that the City of Mercer Island would plan to accommodate 2,000 new housing units and 1,000 new jobs between 2006 and 2031. GMA requires jurisdictions to plan for 20 years of forecasted growth, so the growth target time horizon was extended out to 2035 (see Table 3).

Table 3 - Growth Targets

Housing Growth Target (in units)

Original growth target, 2006-2031


Adjusted growth target, 2006-2035


Employment Growth Target (in jobs)

Original growth target, 2006-2031


Adjusted growth target, 2006-2035


Employment and Commercial Capacity

According to the Puget Sound Regional Council, as of March 2010 there are approximately 6,622 jobs on Mercer Island. The City’s analysis completed to inform the 2014 King County Buildable Lands Report shows that Mercer Island has the capacity for a total of 2,373 new jobs; well in excess of the 1,160 growth target for which Mercer Island must have sufficient zoned land to accommodate.

Residential Growth

The Comprehensive Plan contains three types of housing figures: a capacity estimate, a growth target, and a housing and population forecast. Each of these housing numbers serves a different purpose.

Housing Capacity

As required in a 1997 amendment to the Growth Management Act (RCW 36.70A.215), recent growth and land capacity in King County and associated cities have been reported in the 2014 King County Buildable Lands Report.

The capacity estimate identifies the number of new units that could be accommodated on vacant and redevelopable land under current zoning. The capacity estimate is not a prediction of what will happen, merely an estimate of how many new units the Island could accommodate based on our current zoning code, the number and size of vacant properties, and some standard assumptions about the redevelopment potential of other properties that could accommodate additional development.

According to the 2014 Buildable Lands Report, the City of Mercer Island has the capacity for 2,004 additional housing units on properties designated for residential uses through new development on vacant lands and/or through redevelopment of underutilized lands. Based on zoning and redevelopment assumptions done in 2012 for the Buildable Lands Report, about 614 new housing units could be accommodated in single family zones, 143 new housing units could be accommodated in multifamily zones and 1,247 units could be accommodated in the Town Center.

Redevelopable land in the Town Center was determined based on an analysis of those parcels which currently have an improvement to land value ratio of .5 or less and are not in public or utility ownership. Additionally, townhomes and condominium properties were not considered redevelopable, and only those properties allowing 2.5 residential units or more are included in the analysis. Future assumed densities for this preliminary figure were based on the density of recently permitted projects (2/3 mixed-use, 1/3 commercial only). This methodology used in the 2014 Buildable Land Analysis is a similar methodology used in the 2007 Buildable Lands Report.

Housing Targets

As mentioned above, the City has a King County Growth Management Planning Council (GMPC) 2035 housing target of 2,320 new units. The housing target represents the number of units that the City is required to plan for under the Growth Management Act. The housing target is not necessarily the number of units that will be built on Mercer Island over the next two decades. Market forces, including regional job growth, interest rates, land costs, and other factors will have a major influence on the number of actual units created.

Housing and Population Forecast

The third type of housing figure contained in the Comprehensive Plan is a local housing forecast. Table 4 contains a housing unit and population forecast for 2010 through 2030 conducted by the Puget Sound Regional Council (PSRC), using a parcel-based land use model called UrbanSim, based on existing zoning and land use designations.

PSRC anticipates an increase in housing units at an average annual growth rate of approximately 0.25% between 2010 and 2040. This represents an increase of approximately 453 housing units and 1,495 people over 30 years.

The Housing Unit and Population forecasts are informed estimates based on several factors such as growth trends for new single family and accessory dwelling units over the last several years, Puget Sound Regional Council forecasts of future household size, transportation systems and demand modeling, and real estate market fluctuations.

Given the uncertainty of future market forces, periodic reviews of housing and population forecasts should be made to evaluate the future growth assumptions. Adjustments to this forecast will also be necessary if the projections on household size and population growth vary significantly from those forecasted. Planning staff predict that PSRC’s multifamily unit growth estimates for the period through 2030 are likely to be surpassed as early as 2020. This prediction is based on the established pattern of larger, mixed use developments adding 100-200 units at a time to the City’s multifamily housing supply and projects that are now in the development pipeline. The City will continue to monitor housing unit, population growth and market trends, and adjust land use, transportation, and capital facilities planning as necessary prior to the next major Comprehensive Plan update in 2023.

Housing Density

The average allowed density in the City of Mercer Island is more than 6.2 dwelling units per acre. This figure is based on the proportional acreage of each land use designation (or zones) that allows residential development, the densities permitted under the regulations in place today for that zone, and an assumption that the average practical allowed density for the Town Center is 99.16 units per acre. Since there is no maximum density in the Town Center and density is controlled instead by height limits and other requirements, the figure of 99.16 units per acre represents the overall achieved net density of the mixed-use projects in the Town Center constructed since 2006.

Table 4 – 2010-2030 Housing Unit and Population Forecast


Overall Household Size

SFR Units

Multi-family Units

Total Increase in units per decade

Total Housing Units


2010 (Census)







2020 (Forecast)







2030 (Forecast)







2010 household size data obtained from the 2010 Census. All other data is from PSRC, using their 2013 Forecast parcel-based land use model using Urban Sim.


Town Center

1.The Town Center land designated for commercial retail, service and office uses is much larger than the local population can support. This has contributed to a historical pattern of relatively low private investment in downtown properties. Consequently, the Town Center consists of many one story strip centers, surrounded by vast parking lots (FAR of only 0.23); a typical suburban sprawl-like development.

2.In 1994, the City made significant street improvements in the Town Center, which have resulted in a more pedestrian-friendly environment. However, more needs to be done on the private development side to design buildings with attractive streetscapes so that people will have more incentive to park their car and walk between shopping areas.

3.The Town Center is poorly identified. The major entrance points to the downtown are not treated in any special way that invites people into the business district.

Outside the Town Center

1.The community needs to accommodate two important planning values -- maintaining the existing single family residential character of the Island, while at the same time planning for population and housing growth.

2.Accessory housing units are allowed by City zoning regulations, and offer a way to add housing capacity to single family residential zones without disrupting the character.

3.Commercial Office and PBZ zones must serve the needs of the local population while remaining compatible with the overall residential character of the community.

4.Ongoing protection of environmentally sensitive areas including steep slopes, ravines, watercourses, and shorelines is an integral element of the community’s residential character.

5.View protection is important and must be balanced with the desire to protect the mature tree growth.

6.Within the bounds of limited public resources, open space and park land must be preserved to enhance the community’s extraordinary quality of life and recreation opportunities.

7.There is a lack of pedestrian and transit connections between the Town Center, the Park and Ride, and Luther Burbank Park.


Town Center




THE HEART of Mercer Island and embody a small town character, where residents want to shop, eat, play and relax together.


ACCESSIBLE to people of all ages and abilities.


CONVENIENT to enter, explore and leave with a variety of transportation modes.


WELL DESIGNED with public spaces that offer attractive settings for entertainment, relaxation and recreation.


DIVERSE with a range of uses, building types and styles that acknowledge both the history and future of the Island.


LOCAL providing businesses and services that meet every day needs on the Island.


HOME to a variety of housing options for families, singles and seniors.


Create a mixed-use Town Center with pedestrian scale and connections.

1.1A walkable mixed-use core should be located adjacent to a regional transit facility and be of sufficient size and intensity to create a focus for Mercer Island.



Create a policy and regulatory structure that will result in a diversity of uses that meets Islanders’ daily needs and helps create a vibrant, healthy Town Center serving as the City’s business, social, cultural and entertainment center.

2.1Use a variety of creative approaches to organize various land uses, building types and heights in different portions of the Town Center.


Have a mixture of building types, styles and ages that reflects the evolution of the Town Center over time, with human-scaled buildings, varied height, set-backs and step-backs and attractive facades.

3.1Buildings taller than two stories may be permitted if appropriate public amenities and enhanced design features are provided.

3.2Locate taller buildings on the north end of the Town Center and step down building height through the center to lower heights on the south end, bordering Mercerdale Park. See Figure TC-1.

Figure TC-1: Town Center subareas and height limits

3.3Calculate building height on sloping sites by measuring height on the lowest side of the building.

3.4Mitigate the “canyon” effect of straight building facades along streets through use of upper floor step-backs, façade articulation, and similar techniques.

3.5Buildings on larger parcels or with longer frontage should provide more variation of the building face, to allow for more light and create the appearance of a smaller scale, more organic, village-like development pattern. Building mass and long frontages resulting from a single user should be broken up by techniques such as creating a series of smaller buildings (like Island Square), providing public pedestrian connections within and through a parcel, and use of different but consistent architectural styles to create smaller building patterns.

3.6Building facades should provide visual interest to pedestrians. Street level windows, minimum building set-backs, on-street entrances, landscaping, and articulated walls should be encouraged.


Create an active, pedestrian-friendly retail core.

4.1Street-level retail, office, and service uses should reinforce the pedestrian-oriented circulation system.

4.2Retail street frontages (Figure TC-2) should be the area where the majority of retail activity is focused. Retail shops and restaurants should be the dominant use, with personal services also encouraged to a more limited extent.


Encourage a variety of housing forms, including townhomes, apartments and live-work units attractive to families, singles, and seniors at a range of price points.

5.1Land uses and architectural standards should provide for the development of a variety of housing types, sizes and styles.

5.2Encourage development of low-rise multi-family housing in the TCMF subareas of the Town Center.

5.3Encourage the development of affordable housing within the Town Center.

5.4Encourage the development of accessible housing within the Town Center.

5.5Encourage options for ownership housing within the Town Center.

Figure TC-2: Required Retail Frontage Types



Be convenient and accessible to people of all ages and abilities, including pedestrians, bicyclists, transit users and motorists.


Town Center streets should be viewed as multiple-use facilities, providing for the following needs:

Access to local businesses and residences

Access for emergency vehicles

Routes for through traffic

Transit routes and stops

On-street parking

Pedestrian and bicycle travel

Sidewalk activities, including limited advertising and merchandising and restaurant seating.

Occasional special events and outdoor entertainment

7.1All Town Center streets should provide for safe and convenient multi-modal access to existing and future development in the Town Center.

7.2Design streets using universal design principles to allow older adults and individuals with disabilities to “stroll or roll”, and cross streets safely.

7.378th Avenue SE should be the primary pedestrian corridor in the Town Center, with ample sidewalks, landscaping and amenities.

7.477th Avenue SE should serve as the primary bicycle corridor connecting the regional bicycle network along I-90 and the planned light rail station with Mercerdale Park and the rest of the Island south of the Town Center.


Be pedestrian-friendly, with amenities, tree-lined streetscapes, wide sidewalks, storefronts with canopies, and cross-block connections that make it easy to walk around.

8.1Provide convenient opportunities to walk throughout Town Center.

8.2Create safe pedestrian routes that break-up larger city blocks.


Have ample parking, both on-street and off, and the ability to park once and walk to a variety of retail shops.

9.1Reduce the land area devoted to parking by encouraging structured and underground parking. If open-air, parking lots should be behind buildings.

9.2Encourage improved access to transit, bicycle, pedestrian and shared parking facilities to reduce trip generation and provide transportation alternatives, particularly for secondary trips once users reach the Town Center.

9.3Consider a range of regulatory and incentive approaches that can increase the supply of public parking in conjunction with development proposals.

9.4On and off-street parking should be well-lit, convenient and well-signed so that drivers can easily find and use parking.

9.5Develop long-range plans for the development of additional commuter parking to serve Mercer Island residents.

9.6Prioritize parking for Mercer Island residents within the Town Center.

GOAL 10:

Prioritize Town Center transportation investments that promote multi-modal access to regional transit facilities.

GOAL 11:

Promote the development of pedestrian linkages between public and private development and transit in and adjacent to the Town Center.


GOAL 12:

Have inviting, accessible outdoor spaces with seating, greenery, water features, and art that offer settings for outdoor entertainment and special events as well as for quiet contemplation.

12.1Outdoor public spaces of various sizes in Town Center are important and should be encouraged.

12.2Encourage the provision of on-site open space in private developments but allow development agreements and payment of a calculated amount of money as an option to dedication of land. In addition, encourage aggregation of smaller open spaces between parcels to create a more substantial open space.

12.3Investigate potential locations and funding sources for the development (and acquisition if needed) of one or more significant public open space(s) that can function as an anchor for the Town Center’s character and redevelopment. Identified “opportunity sites” are shown in Figure TC-3 and described below. These opportunity sites should not preclude the identification of other sites, should new opportunities or circumstances arise.

Figure TC-3: Possible locations for significant public open space


GOAL 13:

Town Center buildings should meet a high standard of energy efficiency and sustainable construction practices as well as exhibiting other innovative green features, above and beyond what is required by the existing Construction Code.


GOAL 14:

Continue to encourage vitality through the support of economic development activities in the Town Center.

14.1Establish the Town Center as an active and attractive commercial node, including the use of gateways, wayfinding and signage, and links to transit.

14.2Maintain a diversity of downtown land uses.

14.3Support economic growth that accommodates Mercer Island’s share of the regional employment growth target of 1,228 new jobs from 2006-2035, by maintaining adequate zoning capacity, infrastructure, and supportive economic development policies.

14.4Investigate formation of a business improvement area (BIA), or other mechanism authorized by state law, to help promote Island businesses, to support Town Center activities, and to finance improvements and amenities. Identify a staff person who will help coordinate economic development activities.

14.5Support public and private investment in existing properties, infrastructure, and marketing to help maintain longstanding businesses and attract new ones.

14.6Create a healthy economic environment where Town Center businesses can serve the needs of Mercer Island residents as well as draw upon broader retail and commercial market areas.

Outside the Town Center

GOAL 15:

Mercer Island should remain principally a low density, single family residential community.

15.1Existing land use policies, which strongly support the preservation of existing conditions in the single family residential zones, will continue to apply. Changes to the zoning code or development standards will be accomplished through code amendments.

15.2Residential densities in single family areas will generally continue to occur at 3 to 5 units per acre, commensurate with current zoning. However, some adjustments may be made to allow the development of innovative housing types, such as accessory dwelling units and compact courtyard homes at slightly higher densities as outlined in the Housing Element.

15.3Multi-family areas will continue to be low rise apartments and condos and duplex/triplex designs, and with the addition of the Commercial/Office (CO) zone, will be confined to those areas already designated as multi-family zones.

15.4As a primarily single family residential community with a high percentage of developed land, the community cannot provide for all types of land uses. Certain activities will be considered incompatible with present uses. Incompatible uses include landfills, correctional facilities, zoos and airports. Compatible permitted uses such as education, recreation, open spaces, government social services and religious activities will be encouraged.

GOAL 16:

Achieve additional residential capacity in single family zones through flexible land use techniques.

16.1Use existing housing stock to address changing population needs. Accessory housing units and shared housing opportunities should be considered in order to provide affordable housing, relieve tax burdens, and maintain existing, stable neighborhoods.

16.2Through zoning and land use regulations provide adequate development capacity to accommodate Mercer Island’s projected share of the King County population growth over the next 20 years.

16.3Promote a range of housing opportunities to meet the needs of people who work and desire to live in Mercer Island.

16.4Promote accessory dwelling units in single-family districts subject to specific development and owner occupancy standards.

16.5Infill development on vacant or under-utilized sites should occur outside of critical areas and ensure that the infill is compatible with the surrounding neighborhoods.

GOAL 17:

With the exception of allowing residential development, commercial designations and permitted uses under current zoning will not change.

17.1The Planned Business Zone uses on the south end of Mercer Island are compatible with the surrounding single family zone needs. All activities in the PBZ are subject to design review. Supplemental design guidelines have been adopted.

17.2Commercial uses and densities near the I-90/East Mercer Way exit and SE 36th Street are appropriate for that area. All activities in the CO zone are subject to design review and supplemental design guidelines may be adopted.

17.3Inclusion of a range of residential densities should be allowed when compatible in the Commercial Office (CO) zones. Through rezones or changes in zoning district regulations, multi-family residences should be allowed in all commercial zones where adverse impacts to surrounding areas can be minimized. Housing should be used to create new, vibrant neighborhoods.

17.4Social and recreation clubs, schools, and religious institutions are predominantly located in single family residential areas of the Island. Development regulation should reflect the desire to retain viable and healthy social, recreational, educational, and religious organizations as community assets which are essential for the mental, physical and spiritual health of Mercer Island.

Natural Environment Policies

GOAL 18:

The protection of the natural environment will continue to be a priority in all Island development. Protection of the environment and private property rights will be consistent with all state and federal laws.

18.1The City of Mercer Island shall protect environmentally sensitive lands such as watercourses, geologic hazard areas, steep slopes, shorelines, wildlife habitat conservation areas, and wetlands. Such protection should continue through the implementation and enforcement of critical areas and shoreline regulations.

18.2Land use actions, storm water regulations and basin planning should reflect intent to maintain and improve the ecological health of watercourses and Lake Washington water quality.

18.3New development should be designed to avoid increasing risks to people and property associated with natural hazards.

18.4The ecological functions of watercourses, wetlands, and habitat conservation areas should be maintained and protected from the potential impacts associated with development.

18.5The City shall utilize best available science during the development and implementation of critical areas regulations. Regulations will be updated periodically to incorporate new information and, at a minimum, every eight years as required by the Growth Management Act.

18.6Encourage low impact development approaches for managing stormwater and protecting water quality and habitat.

18.7Services and programs provided by the City with regards to land use should encourage residents to minimize their own personal carbon footprint, especially with respect to energy consumption and waste reduction.

18.8The City’s development regulations should encourage long term sustainable stewardship of the natural environment. Examples include preservation and enhancement of native vegetation, tree retention, and rain gardens.

18.9Outreach campaigns and educational initiatives should inform residents of the collective impact of their actions on local, county, and state greenhouse gas emissions reduction goals.

Parks and Open Space Policies

GOAL 19:

Continue to maintain the Island’s unique quality of life through open space preservation, park and trail development and well-designed public facilities.

19.2More specific policy direction for parks and open space shall be identified in the Parks and Recreation Plan and the Pedestrian and Bicycle Facility Plan. These plans shall be updated periodically to reflect changing needs in the community.

19.3Acquisition, maintenance and access to public areas, preserved as natural open spaces or developed for recreational purposes, will continue to be an essential element for maintaining the community’s character.

19.4View preservation actions should be balanced with the efforts to preserve the community’s natural vegetation and tree cover.

19.5Future land use decisions should encourage the retention of private club recreational facilities as important community assets.

19.6Provide recreation and leisure time programs and facilities that afford equal opportunities for use by all Mercer Island residents while considering the needs of non-Mercer Island residents.

19.7Provide a system of attractive, safe, and functional parks, and park facilities.

19.8Preserve natural and developed open space environments and trails for the benefit of all existing and future generations.

19.9Provide a broad representation of public art through cooperation with the Mercer Island Arts Council.

19.10Funding for existing facilities should be a top priority and should be provided at a level necessary to sustain and enhance parks, trails and open space consistent with the Parks and Recreation Plan, the Trails Plan and the Capital Facilities Element.

19.11Promptly investigate open space acquisition opportunities as they become available.

19.12Pursue state and federal grant funding for parks and open space improvements.

19.13Pursue a trail lease agreement from the Washington State Department of Transportation to allow for the development of an I-90 Connector Trail to establish a pedestrian connection between Luther Burbank and Town Center.



To implement land use development and capital improvement projects consistent with the policies of the comprehensive plan.

1.1To focus implementation of the Comprehensive Plan on those issues of highest priority to the City Council and community: Town Center development, storm drainage, critical lands protection, and a diversity of housing needs including affordable housing.

1.2To create opportunities for housing, multi-modal transportation, and development consistent with the City’s share of regional needs.

1.3To make effective land use and capital facilities decisions by improving public notice and citizen involvement process.

1.4To continue to improve the development review process through partnership relationships with project proponents, early public involvement, reduction in processing time, and more efficient use of staff resources.

1.5To continue to improve the usability of the “Development Code” by simplifying information and Code format; eliminating repetitious, overlapping and conflicting provisions; and consolidating various regulatory provisions into one document.

1.6Mercer Island has consistently accepted and planned for its fair share of regional growth, as determined by the GMPC and the King County CPPs. However, build out of the City is approaching, and could occur before 2035 or shortly thereafter. In the future, the City will advocate for future growth allocations from the GMPC which will be consistent with its community vision, as reflected in the Comprehensive Plan and development regulations; environmental constraints; infrastructure and utility limitations; and its remaining supply of developable land.