Unlike the landscape regulations applicable to other parts of the City, the Pilchuck District has no requirements for buffering between adjacent land uses and developments, except to screen specific facilities such as utility and service areas and parking lots. Adjacent buildings and land uses within the Pilchuck District are intended to be visually and functionally compatible to create continuity rather than segregation along streets. The landscaping requirements in this chapter are intended, instead, to visually soften and punctuate the build environment, to provide shade, and to create comfortable places to live, work, shop, and recreate by incorporating built and natural forms.
A. Areas in excess of the impervious surface limits shown in Tables V-1 through V-4 shall be landscaped. This shall represent the minimum percentage of site area in landscaping and additional area may be required to meet other regulations or conditions of approval for a development proposal. Landscaping should be appropriate to urban areas, and may include decorative hardscape such as brick or paver walkways and plazas provided that permeable materials are used, screening and shading of parking areas, and landscaping of setback areas. In general, all areas that are not used for building, parking, or access, or other ancillary functions shall be landscaped.
B. To lessen the visual impact of outdoor parking areas and to provide shade, parking lots with 10 or more parking stalls shall provide interior landscaping. Interior landscaping shall consist of landscape islands, each of sufficient dimensions to accommodate a circle 5 feet wide exclusive of curbs. Landscape islands shall be separated by no more than 7 consecutive parking stalls. Each landscape island shall contain a minimum of 1 deciduous tree of a species characterized by a spreading canopy and ground cover at sufficient density to provide 75 percent coverage within 2 years. A minimum of one tree per 10 spaces shall be provided in landscape islands and/or perimeter beds. Trees shall be a minimum of 2.5 inch caliper measured 4 feet above grade at planting. Trees and shrubs shall provide adequate allowance for vehicle doors to protect vegetation and shall be protected by continuous or intermittent curbing. The overall parking lot landscape design shall disperse tree locations as evenly as practical. A determination of equivalence may be requested for alternative parking lot landscaping that meets the intent of this section.
C. Street trees are required consistent with the standards in Article III. The location and type of existing street trees on the block shall be evaluated at the time of development application to determine whether the existing type should be continued and whether the interval specified in Article III will require the placement of one or more trees as part of the proposed development. Street trees shall be a minimum of 2.5 inches in diameter measured 4 feet above surrounding grade at planting. For street trees to be installed within paved areas, the use of structural soil planting beds, continuous soil trenches, or root path trenches may be required in order to maximize the ability of the tree to thrive and perform well in the urban environment. A tree box may be required for street drainage.
D. Provisions specific to the Neighborhood Single Family and Neighborhood Townhouse zones:
1. No paving shall be permitted within the front setback except for pedestrian access routes unless the Review Authority determines that no alternative site access is practical.
2. For townhouse development, a minimum of one tree shall be planted within the private frontage for each 30 linear feet of site frontage. Trees shall be a variety appropriate to the space and conditions available.
3. Fences within a private frontage shall be no taller than four feet at the highest point and shall be open rather than solid to allow light and visual access through the fence. Walls within a private frontage shall be no taller than three feet at the highest point, with an additional one foot of ornamental ironwork permitted.
E. Provisions specific to Neighborhood Center and Civic zones:
1. Any pavement between the building and the sidewalk shall appear as an extension of the sidewalk.
2. An area equal to 50 percent of the required pervious area or three percent of the net residential square footage (whichever is larger) shall be developed as shared open space. Shared open spaces may be designed for either active or passive activities. They should include places to sit, areas of both shade and sun, and may include a feature such as a fountain or art piece. Where the open space is adjacent to a public walkway, street, or plaza, provision should be made for direct access from the shared open space to the public open space, and may include provision to secure the shared open space from public entry at appropriate times. Shared open spaces may be located on a level that is above ground level and is not part of the surface landscaped area, but in this case it will not be counted as meeting the landscaping requirement. Shared open spaces may be limited to use by residents of the building in which they are located. Shared open space shall not be directly adjacent to a parking area unless adequately screened with landscaping and accessible without walking through the parking lot.
3. The use of security fences should be minimized and limited to special locations where additional security is necessary. Such security fences shall not exceed 6 feet in height and should be designed to maintain a visually open character to the extent possible. This may be accomplished by using metal picket or open grille fencing or by mounting metal picket or open grille fencing on top of a low masonry wall.
4. In no case shall chain link fencing, with or without coating or slats, razor ribbon, or barbed wire be allowed.