Proposition K Technical Memo

Transcription

1 Maxwell & Associates Environmental Planning Consultants March 30, 2009 Proposition K Technical Memo To: Ms. Joy Navarette Mr. Kevin Guy San Francisco Planning Department From: Sally Maxwell, Principal Maxwell & Associates Adam Noble, Principal CADP Re: E: 555 Washington Street Project Proposition K Shadow Analysis (for a 390-Foot Project, 357-Foot Office Variant, and 200-Foot Code-Complying Alternative). Introduction This memorandum examines the potential of shadows from the proposed project to impact properties protected by Proposition K, the Sunlight Ordinance, as codified in Section 295 of the Planning Code. Environmental Science Associates (ESA) prepared a screening analysis that excludes four of the public parks (Woh Hei Yuen Recreation Center and Park, Willie Wong Playground, Justin Herman / Embarcadero Plaza II, and Portsmouth Square) in the area from analysis. 1 The project s shadows would either not reach these parks or intervening buildings would block shadows from the project. Both Maritime Plaza and Sue Bierman Park (formerly known as East Ferry Park or Embarcadero Plaza I and West Ferry Park) would be subject to potential shading from the proposed project. CADP then quantifies shadow impacts from three alternative projects on Maritime Plaza and Sue Bierman Park. This memorandum analyzes whether the shadow impact of any of the three alternative projects on the two park properties protected by the Sunlight Ordinance would be significant. This memorandum examines the project and two alternatives (or variants). The project would provide approximately 331,640 square feet of residential, 6,780 square feet of retail, and 230 parking spaces in a 390-foot-tall building with mechanical penthouse reaching to a maximum height of 425 feet (see Figure 1, below). The office variant would provide approximately 310,000 square feet of office, 5,540 square feet of retail, and 90 parking spaces in a 357-foot-tall building with mechanical penthouse reaching to a maximum height of 390 feet (see Figure 2, below). The code-complying alternative would provide approximately 331,770 gross square feet of residential, 6,780 square feet of retail, and 230 parking spaces in a 200-foot-tall building with mechanical penthouse reaching to a maximum height of 220 feet. As part of the proposed project, the office variant, and the code-complying alternative, the project sponsor proposes to expand the existing private open space at the base of the building. 2 The project 1 Technical Memorandum, Charles Bennett and Elizabeth Kanner, Environmental Science Associates, to Sally Maxwell, Maxwell & Associates, December 9, Redwood Park is privately owned by the project sponsor. Although not required to be a public open space, the property owner currently makes it accessible to the public during daylight hours Monday through Friday. Phone: (510) Grand View Drive Berkeley, California 94705

2 sponsor would also subdivide a portion of such expanded open space (an expanded Redwood Park) and convey to the City approximately 22,022 square feet of open space to create a new public downtown park. This new park would be placed under the jurisdiction of the Recreation and Park Department and would be protected by Proposition K. Private open spaces, such as Redwood Park and the Sydney G Walton Square, are not subject to the shading restrictions of Planning Code Section 295. Figure 1: Proposed Project Figure 2: Office Variant Source: ESA, 2007 based on plans from Heller-Manus Architects Setting The project site is located on the northwestern corner of Sansome and Washington Streets on the block bounded by Washington, Sansome, Clay, and Montgomery Streets in San Francisco (commonly referred to as 555 Washington Street). The site includes lots 33, 35, and 36 of Assessor s Block 207 along with Mark Twain Alley (a section of Merchant Street) that is proposed to be vacated by the project. Lot 33 is currently occupied by Redwood Park, a private open space area at the base of the Transamerica Pyramid. Lot 35 is occupied by a 100-foot-tall, nine-story office building on Sansome Street and a single-story structure on Washington and Sansome Streets. Lot 36 on Washington Street is currently vacant. The topography in the vicinity is nearly level, with a slight eastward slope down Washington and Clay Streets. The project site is close to the following six properties under the jurisdiction of the Recreation and Park Department that are protected under Section 295 of the San Francisco Planning Code: Sue Bierman Park, between Clay Street including the easterly extension of Clay Street, Washington Street, Davis Street, and The Embardero, formerly called East Ferry Park (or Embarcadero Plaza I) and West Ferry Park; Maritime Plaza, between Clay, Washington, Battery, and Davis Streets; Woh Hei Yuen Recreation Center and Park; 555 Washington Street Project 2 of 19 March 30, 2009

3 Willie Wong Playground; Justin Herman / Embarcadero Plaza II; and, Portsmouth Square Maritime Plaza Maritime Plaza is a 1.93 acre (83,936 square-foot)3 urban plaza located on the northern edge of the Financial District in San Francisco. The plaza is located in Assessor s Block 204, on lots 19, 20, 21, 23, and 24. Assessor s Block 204 is bounded by Washington Street to the north, Battery Street to the west, Davis Street to the east, and Clay Street to the south, and is developed with commercial and open-space uses. The Maritime Plaza open space is above street grade, located on a podium built over a parking garage. The 24-story Alcoa (One Maritime Plaza) building divides the plaza into two connected, symmetrical sections on the block. Two single-story buildings are located on the eastern and western perimeters of the open space. Maritime Plaza consists of both hard and softscaped (landscaped) spaces and contains areas for mainly passive uses. Because of its above-grade location, the open space is mostly used by nearby office workers and residents during lunch, although even then it is underutilized. Sue Bierman Park Sue Bierman Park is a roughly 4-acre (189,475 sq. ft.) site, bounded by Washington Street to the north, The Embarcadero to the east, Clay Street to the south, and Davis Street to the west. Located on Assessor s Block 202 and 203, these blocks were formerly part of a right-of-way occupied by the Clay Street on-ramp to the Embarcadero Freeway, demolished subsequent to the 1989 Loma Prieta earthquake. The State conveyed ownership of these parcels to the City in Jurisdiction over these blocks was transferred by the Board of Supervisors from the Department of Public Works to the Recreation and Park Department in May Assessor s Block 203 is shaded for much of the time, with about 52 percent of the annual sun resource in the shadow of surrounding development over the course of the entire year. The block is sloped from east to west, although the northern perimeter is at street grade and is generally flat. A network of walkways, stairs and terraces meanders up the slope to meet a pedestrian bridge crossing Davis Street to Maritime Plaza. The open space is densely planted with trees. Shaded seating is offered on the low walls that surround the terraces. The northern and eastern perimeters of this block s open space are lawn. A walkway traverses the block diagonally from the southeast corner to the northwest corner. This walkway is well used by residents and office workers. Assessor s Block 202 is a relatively sunny downtown open space, with about 16 percent of the annual sun resource in shadow over the course of the entire year. When shadows from existing development cover this block, they occur almost entirely in the afternoon hours. The open-space area consists of lawns and paved walkways with trees planted along the perimeter. The block is nearly flat except at the eastern and southern perimeters, which are bermed. An open frame structure covers a portion of the walkway running from east/west along the northwestern section of the open space on the block. The open space generally attracts pedestrians passing through the open space and downtown office workers during their lunchtime. 3 The Planning and Recreation & Parks Commissions adopted shadow criteria for 15 downtown parks setting an Absolute Cumulative Limit for new shadow, setting qualitative criteria for assessing new shadow on properties where new shadow would be allowed, and quantifying the size of the parks, including Maritime Plaza open space. 555 Washington Street Project 3 of 19 March 30, 2009

4 Under Proposition K, existing shadow coverage was calculated for Maritime Plaza and Assessor s Block 202 of Sue Bierman Park (formerly East Ferry Park or Embarcadero Plaza II) in October The Planning Department memorandum setting forth the results of the 1987 survey shows the following shadow coverage: Maritime Plaza 68.4 percent and East Ferry Park 35.1 percent. 4 Existing coverage for Assessor s Block 203 of Sue Bierman Park (formerly West Ferry Park), as a newer Proposition K property, was not calculated in the October 1987 memorandum. Updated analysis of the shadow/sun on Sue Bierman Park is shown in the chart below in square foot hours (SFH). Based on this analysis, the shadow coverage calculations result in existing shadow coverage on Assessor s Block 202 of percent and existing shadow coverage on Assessor s Block 203 of percent. Based on the lack of new development in the Maritime Plaza area, the existing shadow coverage has remained constant since 1987 at approximately 68.4 percent. Open Space Existing Shade Existing Sun Total Potential Sun Hours Assessor s Block ,162,115 SFH 288,387,480 SFH 416,549,595 SFH Assessor s Block ,465,053 SFH 122,096,173 SFH 288,561,226 SFH Sue Bierman Park 294,627,168 SFH 410,483,653 SFH 705,110,821 SFH The project vicinity can be characterized as a dense urban environment with buildings ranging from 30 feet to over 600 feet in height. Shadowing of Proposition K open spaces by existing buildings is mainly from fewer than a dozen of the taller highrise buildings in the financial district, including especially the four Embarcadero Center highrise buildings, which shadow the open space primarily from midmorning to mid-afternoon. The existing buildings surrounding the project site, including the Transamerica Pyramid and the Alcoa building, cast shadow on Maritime Plaza in the afternoon hours and on Sue Bierman Park in the later afternoon hours. At those particular times of day and times of year when shadow from the project or either of the alternatives could reach these two open spaces, the eastern half of Maritime Plaza and Sue Bierman Park are already heavily shadowed. Both parks tend to experience less shadowing in the morning and more shadowing in the afternoon. Woh Hei Yuen Recreation Center and Park Woh Hei Yuen Recreation Center and Park encompasses approximately 0.39 acres on the southwest corner of Powell Street and John Alley. The park is located in Assessor s Block 180, on lots 28, 29, 30, 4, 4A, 5, and 8. Assessor s Block 180 is bounded by John Street to the north, Mason Street to the west, Powell Street to the east and Jackson Street to the south, and is developed with residential, commercial and open-space uses. The park is at an elevation of approximately 130 feet re: SF Datum. Based on its area of 16,800 square feet and using the standard City factor of 3,721.4 Proposition K hours per year for each square foot of park area, Woh Hei Yuen Recreation Center and Park has a potential sunlight availability 5 of nearly 63 million square-foot-hours of Proposition K sunlight year-round. Willie Wong Playground Willie Wong Playground lies north of Sacramento Street between Waverly Place and Hang Ah Alley. The approximately 0.65 acre playground occupies Lot 18 of Assessor s Block 225. Assessor s Block 4 Note that the 1987 survey did not include Lots 6, 14 and 15, the southern portion of the open space which was not under the jurisdiction of the Recreation and Park Department at that time. 5 Sunlight availability is defined as the product of the ground area and time of sun exposure; the unit of measure, a squarefoot-hour of sunlight, is defined as sunlight on one square foot of ground for one hour. To calculate available sunlight, a standard factor of 3,721.4 Proposition K hours per year of sunlight exposure for each square foot of park area is applied. 555 Washington Street Project 4 of 19 March 30, 2009

5 225 is bounded by Sacramento, Grant, Clay and Stockton Streets. The park is at an elevation of approximately 102 feet re: SF Datum. Based on its area of 28,450 square feet, the Willie Wong Playground has a potential sunlight availability of nearly 106 million square-foot hours of Proposition K sunlight year-round. Justin Herman / Embarcadero Plaza II Justin Herman / Embarcadero Plaza II, is on the blocks bounded by Sue Bierman Park to the north, Steuart and Drumm Streets to the west, The Embarcadero to the east, and Don Chee Way to the south. The plaza is located on lot 35 of Assessor s Block 233 as well as lots 1, 2, and 18 of Assessor s Block The approximate 3.44 acre open space is located at the foot of Market Street and is mainly characterized by large open paved and grassy areas. The park elevation is at 0 feet re: SF Datum. Based on its area of 150,054 square feet, Justin Herman / Embarcadero Plaza II has a potential sunlight availability of approximately 558 million square-foot-hours of Proposition K sunlight year-round. Portsmouth Square Portsmouth Square is located on lot 17 of Assessor s Block 209. The approximate 1.29 acre park is on the east side of the block bounded by Washington Street to the north, Kearny Street to the east, Grant Avenue to the west, and Clay Street to the south. The park is at an elevation of approximately 34 feet re: SF Datum. Based on its area of 56,186 square feet, Portsmouth Square has a potential sunlight availability of approximately 209 million square-foot-hours of Proposition K sunlight year-round. Project Site and Vicinity The project vicinity can be characterized as a dense urban environment with buildings ranging from 30 feet to over 600 feet in height. Shadowing of Proposition K open spaces by existing buildings is primarily from fewer than a dozen of the taller highrise buildings in the financial district, including especially the four Embarcadero Center highrise buildings and the Transamerica Pyramid. The existing buildings on and immediately surrounding the project site, including the existing Transamerica Pyramid, the Washington Montgomery tower and the four Embarcadero Center towers, cast shadow on the open spaces in question. The Transamerica Pyramid casts shadows on the Willie Wong Playground and on Portsmouth Square in the morning hours while the four Embarcadero Center towers shade Justin Herman / Embarcadero Plaza II in the later afternoon hours. At those particular times of day and times of year when shadow from the project could reach these three open spaces, the open spaces are already heavily shadowed. Figure 3, below, shows an aerial photograph of the project area and identifies the highrise buildings discussed in this technical memorandum. Among the factors that are critical to determining shadow are the specific elevations of each part of the project structure and of each part of the open spaces as well as the horizontal distance and the angular relationship between them. Differences in height are addressed by using elevations referenced to the SF Datum and all distances are measured horizontally. For the project, the midpoint of the lot is at an elevation of approximately 3 feet re: SF Datum. So the project s roof would be at an elevation of 393 feet re: SF Datum and the top of the mechanical screen would be at an elevation of 428 feet re: SF Datum. San Francisco Planning Code Section 295 The Sunlight Ordinance was adopted through voter approval of Proposition K in November 1984 to protect specified public open spaces from shadowing by new structures. As codified in Planning Code 555 Washington Street Project 5 of 19 March 30, 2009

6 Montgomery/ Washington Transamerica Embarcadero Embarcadero Embarcadero Embarcadero Hilton Hotel Tower Pyramid Project Site Center 1 Center 2 Center 3 Center 4 Project Site 601 Montgomery Building Alcoa Building (One Maritime Plaza) Hyatt Regency Hotel Figure 3: Aerial Photograph of the Project Area Source: ESA, 2008 Section 295, Proposition K prohibits the issuance of building permits for structures or additions to structures greater than 40 feet in height that would add shadow to property under the jurisdiction by the Recreation and Park Department, during the period from one hour after sunrise to one hour before sunset at any day of the year. An exception is allowed when the Planning Commission in concert with the Recreation and Park Commission determines that such new shadow would have an insignificant effect on the use of that property. Pursuant to the requirements of Proposition K, in 1987, the two Commissions adopted shadow criteria for 15 downtown parks which sets an Absolute Cumulative Limit for new shadow for each of the identified properties and sets qualitative criteria for assessing new shadow on properties where new shadow would be permitted. For projects that would affect parks for which an Absolute Cumulative Limit was established, shadow impacts have typically been judged less than significant if the project would not exceed the Absolute Cumulative Limit for that park. Pursuant to the 1987 memorandum, the Absolute Cumulative Limit for Assessor s Block 202 of Sue Bierman Park (former East Ferry Park or Embarcadero Plaza I) was set at zero, allowing no additional shadow without a finding of insignificance from the commissions. However, no formal criteria for the significance of new shadow on the southern portion of the Assessor s Block 202 (Lots 6, 14 and 15) have been adopted and the Absolute Cumulative Limit has not been updated to take into account demolition of the Embarcadero Freeway and ramps demolished following the 1989 Loma Prieta earthquake. Likewise no formal criteria for the significance of new shadow on the Assessor s Block 203 (former West Ferry Park) have been adopted as this property was not under Recreation and Park Department jurisdiction at the time the criteria were adopted. The Recently established Sue Bierman Park (which combines the former East and West Ferry Parks) has no Absolute Cumulative Limit. The 1987 Commissions set the Absolute Cumulative Limit for Maritime Plaza to zero citing the existing heavy shadow impact on the park. 555 Washington Street Project 6 of 19 March 30, 2009

7 Without established criteria, assessment of significance of shadow impacts on the parks involves a case-by-case analysis of whether new shadow created by a project would have a significant adverse impact on use of the park. Project shadow at a single time is quantified and expressed as the area covered by project shadow in square feet (SF) and as a percentage of total park area. Project shadow over the course of a day or year occurs over both space and time and is quantified in units called square foot-hours (SFH). Total square foot-hours for a particular day equals the entire area of the open space, multiplied by the number of daylight hours (measured from one hour after sunrise until one hour before sunset) on that day. While this number varies daily, the total square foot hours over the entire year is constant. New shadow, measured in SFH, is an area of park covered by new shadow multiplied by the number of hours the area remains shaded. The extent of additional project shadow is expressed as a percentage of a park s total square foot-hours that would be in shade following project construction. Proposition K Screening Methodology The methodology used by the Planning Department to perform the initial screening for Proposition K impacts typically does not consider elevation data, either for a project or an affected open space, so it may not correctly assess the potential for a project to shadow an open space when the project base is at a different elevation. The detailed analysis ESA uses here considers true elevations relative to SF Datum and therefore produces correct results. To evaluate the year-round Proposition K impact on Woh Hei Yuen Recreation Center and Park, Willie Wong Playground, Justin Herman / Embarcadero Plaza II, and Portsmouth Square, ESA used a screening process to identify all possible days and times of the year for which the shadows from the subject property could reach these parks. The screening analysis does not exclude either Martime Plaza or Sue Bierman Park from impact analyses. Woh Hei Yuen Recreation Center and Park Because Woh Hei Yuen Recreation Center and Park is located approximately five blocks west and two blocks north of the project site and is approximately 130 feet higher in elevation than the project site, shadow from the project alone, considering only the distance and elevation difference, and regardless of the intervening buildings, could not reach the open space during Proposition K times during the year. As such, this open space will not be considered further in this technical memorandum. Please see the attached graphic illustration of this in the 555 Washington Shadow Study, prepared by Heller-Manus Architects. Willie Wong Playground The Willie Wong Playground is approximately three blocks west and one block south of the project site and is approximately 100 feet higher in elevation than the project site. However, the Willie Wong Playground is close enough to the project site that, if it were not for the intervening buildings, the project shadow could reach the playground when the sun is relatively low in the eastern part of the sky, which only could occur during the first Proposition K minutes of the day near the summer solstice. Although there are many other morning times throughout the year when the sun would cast shadows in the direction of the playground, that shadow from the project would not extend far enough to the south to reach the playground at those other times and dates. The shortest horizontal distance between the project site and the playground is the distance from the southwest corner of the project site to the northeast corner of the playground, a distance of just over 1,500 feet, which corresponds to a sun azimuth angle of approximately 20. To reach the playground along that line, the project shadow would have to reach horizontally at least 1,500 feet, which could happen only if the sun altitude angle were less than 13. The distance to the playground, measured 555 Washington Street Project 7 of 19 March 30, 2009

8 from the project site along any other sun azimuth angle, is more than 1,500 feet, so the corresponding critical sun altitude angle would be even smaller. Given the sun position parameters and the angular relationship and distance from the project site to the playground, the potential occurrence of project shadow on the playground corresponds to sun azimuth angles between 19º and 21º, with the first occurring when the last Proposition K minute-of-theday shadow would reach the playground on July 5th and the latter occurring at 7 a.m. on July 12th. The following conditions hold: When the sun altitude angle is more than 12.03, the project shadow would be too short to reach the playground. When the sun azimuth angle is not between º and º, shadow would not point toward the playground. Thus, the use of the sun altitude angle and the º and º azimuth angle range identifies all Proposition K times when project shadow could reach the Willie Wong Playground. Justin Herman / Embarcadero Plaza II Justin Herman / Embarcadero Plaza II is approximately five blocks east and one block south of the project site and is approximately 3 feet lower in elevation than the project site. If not for the presence of the intervening buildings, the project would shade the plaza when the sun is relatively low in the western part of the sky, which occurs during the last few Proposition K minutes-of-the-day around the summer solstice. Although there are many other afternoon times throughout the year when the sun would cast shadows in the direction of the plaza, that shadow from the project would not be long enough or extend far south enough to reach the plaza at other times and dates. The shortest horizontal distance between the project site and the plaza is the distance from the southeast corner of the project site to the northwest corner of the plaza, just over 1,680 feet, which corresponds to a sun azimuth angle of approximately about 182. To reach the plaza along that line, the project shadow would have to extend horizontally at least 1,680 feet, which could happen only if the sun altitude angle were less than approximately 15. The distance to the plaza, measured from the project site along any other sun azimuth angle, is more than 1,680 feet and the corresponding critical sun altitude angle is less than 15. Given the sun position parameters and the angular relationship and distance from the project to the plaza, the potential occurrence of project shadows on the plaza corresponds to sun azimuth angles between 165º and 184º, with the first occurring when the last Proposition K minute-of-the day shadow would reach the plaza on August 2nd and the latter occurring at 6:15 p.m. on September 6th. The following conditions hold: When the sun altitude angle is more than 14.08, the project shadow would be too short to reach the plaza. When the sun azimuth angle is not between º and º, shadow would not reach toward the playground. Thus, the use of the sun altitude angle and the º and º azimuth angle range will identify all Proposition K times when shadow from the proposed project could reach Justin Herman / Embarcadero Plaza II. 555 Washington Street Project 8 of 19 March 30, 2009

9 Portsmouth Square Portsmouth Square is approximately two blocks west and approximately 30 feet higher in elevation than the project site. If it were not for the presence of the intervening buildings, the project shadow would reach the park in the early morning hours from April through the beginning of September, when the sun is low in the eastern part of the sky, which occurs during the first Proposition K minutes of the months near the summer solstice. Although there are many other morning times throughout the year when the sun would cast shadows in the direction of Portsmouth Square, that shadow from the project would not be long enough or extend far south enough to reach Portsmouth Square at other times and dates. The shortest horizontal distance between the proposed project site and Portsmouth Square is the distance from the west edge of the project site and the eastern boundary of the square, a distance of approximately 830 feet, which corresponds to a sun azimuth angle of approximately 0. To reach the square along that line, the project shadow would have to extend horizontally at least 830 feet, which could happen only if the sun altitude angle were approximately 25, or less, above the horizon. The distance from the project to the square, measured along any other sun azimuth angle, is more than 830 feet and the corresponding critical sun altitude angle would be less than 25. Given the sun position parameters and the angular relationship and distance from the project site to the square, the potential occurrence of project shadows on the playground corresponds to sun azimuth angles between 1.448º and º, with the first marking when the 7:45 a.m. project shadow would reach the square on August 30th and the latter marking at 7:00 a.m. on July 12th. The following conditions hold: When the sun altitude angle is more than 25, the project shadow would be too short to reach the square. When the sun azimuth angle is not between 1.448º and º, shadow would not point toward the square. Thus, the use of the 25 maximum sun altitude angle and the 1.448º to º azimuth angle range will identify all Proposition K times when shadow from the project could reach the square. Sun Location Coordinates Applying standard 15-minute-increment Proposition K values of sun azimuth and altitude for San Francisco, the screening process first identified those times of day and days of the year when the sun azimuth would be within the ranges established above for each open space. These values were supplemented with immediately preceding time increments for which the altitude angle was less than or included the associated sun altitude angles established above. All values that fall within that defined range of azimuth angles and are bounded by the defined altitude angle were identified in the screening. These values are shown in the attached tables, which present these events in order of date and time, and which also shows the potential, if intervening buildings were not present, of the project to cast shadow on the open spaces, as determined by the elevation difference between the project and the open spaces and by the sun s azimuth and altitude angles during these times. To apply the above angular and distance relationships, to simulate shadow for the project and vicinity, and to illustrate the potential for Proposition K shadow impact, a digital model was created using aerial photogrammetry and Sanborn data of the San Francisco Downtown area including the project site, Woh Hei Yuen Recreation Center and Park, Willie Wong Playground, Justin Herman / Embarcadero 555 Washington Street Project 9 of 19 March 30, 2009

10 Plaza II, Portsmouth Square and vicinity. ESA imported a digital model of the project, provided by Heller Manus Architects, into the context model. Proposition K Screening Analysis and Results Willie Wong Playground If there were no intervening buildings, the project shadow could reach the Willie Wong Playground when the shadow points directly toward the playground and the sun is quite low in the eastern part of the sky. 6 All of these combinations of sun altitude and azimuth angles that are applied by the Proposition K methodology are shown in Table 1. TABLE 1: SHADOW SCREENING, WILLIE WONG PLAYGROUND Date Time Altitude Angle Azimuth Angle Shadow Length Shadow Long Enough to Reach Park? 21-Jun 7:00 a.m ,845 ft. Yes 28-Jun 7:00 a.m ,908 ft. Yes 5-Jul 6:52.2 a.m ft. Yes 5-Jul 7:00 a.m ft. Yes 12-Jul 6:56.4 a.m ft. Yes 12-Jul 7:00 a.m ft. Yes Source: ESA, Under these conditions, and without intervening buildings, the project shadow would reach well into the Playground. However for most of these azimuth angles, the existing highrise buildings that front Montgomery Street between Washington and Clay streets, including the Transamerica Pyramid on the east side of Montgomery and the Washington Montgomery Tower and the 601 Montgomery tower on the west side of Montgomery, form a continuous barrier that would intercept new shadow from the project and prevent it from reaching the playground during Proposition K hours. At the extreme of the azimuth angle range, when the sun is far enough south to reach around the towers, the 701 Grant Avenue building, on the northwest corner of Grant Avenue and Sacramento Street, and several other existing buildings along Grant Avenue, Waverly, and Clay Streets are sufficiently tall to block new project shadow from reaching into the Playground. The project shadow would reach only onto the walls and roofs of the aforementioned highrise towers and other existing buildings; these buildings would block new project shadow from reaching the playground. The resulting extent of shadow from the project, including the blocking effects of the intervening buildings, which prevent new project shadow from reaching the Playground is shown in Figure 4: Willie Wong Playground Shadow Patterns July 5, 6:52 a.m. Image A of Figure 4 shows the extent of the project shadow, including topography but without intervening buildings. Image B shows current shadowing of the Willie Wong Playground, including topography and existing buildings. Image C shows the reach of the shadow from the project, including topography and showing the blocking effects of the intervening buildings. See also the attached graphic illustration of this in the 555 Washington Shadow Study, prepared by Heller-Manus Architects. Justin Herman / Embarcadero Plaza II If there were no intervening buildings, the project shadow could reach as far as Justin Herman / Embarcadero Plaza II in the afternoon when the sun is low in the western part of the sky and the 6 The sun altitude angle must be less than 12 for the project shadow to be long enough to reach the Playground. 555 Washington Street Project 10 of 19 March 30, 2009

11 Figure 4A, Project Figure 4B, Existing Figure 4C, Existing + Project Not to scale Figure 4: Willie Wong Playground Shadow Patterns July 5, 6:52 a.m. Source: ESA, Washington Street Project 11 of 19 March 30, 2009

12 shadow points directly toward the plaza. 7 Selected examples of the possible combinations of sun altitude and azimuth angles that are applied by the Proposition K methodology are shown in Table 2. TABLE 2: SHADOW SCREENING, JUSTIN HERMAN / EMBARCADERO PLAZA II Date Time Altitude Azimuth Angle Shadow Length Shadow Long Enough to Reach Park? 21-Jun 7:36 p.m ,532 ft. yes 21-Jun 7:15 p.m ,844 ft. yes 21-Jun 7:00 p.m ,470 ft. no 26-Jul 7:00 p.m ,489 ft. no 2-Aug 7:00 p.m ,604 ft. no 2-Aug 7:15 p.m ,058 ft. yes 2-Aug 7:18.6 p.m ,196 ft. yes 9-Aug 7:10.8 p.m ,171 ft. yes 16-Aug 6:45 p.m ,591 ft. no 16-Aug 7:02.4 p.m ,136 ft. yes 23-Aug 6:45 p.m ,836 ft. yes 23-Aug 6:52.8 p.m ,113 ft. yes 30-Aug 6:30 p.m ,687 ft. yes 30-Aug 6:42.6 p.m ,090 ft. yes 6-Sep 6:15 p.m ,572 ft. no 6-Sep 6:31.8 p.m ,079 ft. yes Source: ESA, If there were no intervening buildings, the project shadow could reach into the Plaza on a number of these times and dates. However for all of these azimuth angles, three of the existing highrise Embarcadero Center towers, located between Washington and Clay Streets, the Alcoa Building (One Maritime Plaza tower), the 50 California Street tower, and the Hyatt Regency Hotel building form a continuous barrier that would intercept all new shadow from the project and prevent it from reaching the Plaza during Proposition K hours. The masses of the One Maritime Plaza tower and the Embarcadero Center towers together form a continuous barrier tall enough to intercept all shadow from the proposed project and sufficiently wide to intercept all project shadow except that which could reach the southernmost 80 feet of Justin Herman / Embarcadero Plaza II. At that point in the barrier is a gap between the 50 California and the Embarcadero Center Two towers where the project shadow can extend as far as and be intercepted by the Hyatt Regency building, which itself is tall enough to prevent the project shadow from reaching the surface of the Justin Herman / Embarcadero Plaza II. At any of these times, the Plaza would already be in full shadow from the Hyatt Regency, the Embarcadero Center buildings, 50 California and the mass of the many other buildings in the vicinity. In summary, the project shadow could only reach onto the walls and roofs of the existing highrise buildings, the masses of which would already fully shadow the Plaza and also would block new project shadow from reaching any part of the Plaza. See the attached graphic illustration of this in the 555 Washington Shadow Study, prepared by Heller-Manus Architects. 7 Note that the project shadow that could reach Sue Bierman Park when the shadow is cast north of the One Maritime Plaza tower is analyzed and discussed, below, under Proposition K impacts. 555 Washington Street Project 12 of 19 March 30, 2009

13 Portsmouth Square If there were no intervening buildings, the project shadow could reach Portsmouth Square before 8:30 a.m. while the sun is low in the eastern part of the sky and the shadow points directly toward the Square. Selected examples of the many possible combinations of Altitude and Azimuth angles that are applied by the Proposition K methodology are shown in Table 3, Shadow Screening - Portsmouth Square. Under these conditions, and without intervening buildings, the project shadow could reach well into the Square on a number of times and dates. However for all of these azimuth angles, the existing highrise buildings between Washington and Clay Streets, including the Transamerica Pyramid, the Washington Montgomery Tower, and the Hilton Hotel highrise, form a continuous high barrier that would intercept all new shadow from the project and prevent it from reaching Portsmouth Square during Proposition K hours. The project shadow would reach only onto the walls and roofs of these existing highrise buildings, which would block new project shadow from reaching any part of the Square. The barrier stretches continuously from Washington Street to Clay Street. Because the project is offset to the west due to the lane shift on Washington Street, the easternmost edge of the proposed project aligns with the easternmost edge of the Washington Montgomery Tower so that the shadow from the project cannot reach into Portsmouth Square along the line of Washington Street unless it can overtop the Washington Montgomery Tower, which it cannot. Similarly, project shadow cannot reach the Square along a more westerly line unless it can overtop the Washington Montgomery Tower, the Transamerica Pyramid or the 601 Montgomery Street highrise tower. Since there are no gaps in this barrier and since the barrier is tall enough, the barrier intercepts all project shadow that could otherwise reach Portsmouth Square. 8 At each time when project shadow would reach into Portsmouth Square, the Square would already be shadowed by these three buildings Transamerica Pyramid, Washington Montgomery Tower, and 601 Montgomery Street highrise. See the attached graphic illustration of this in the 555 Washington Shadow Study, prepared by Heller-Manus Architects. Screening Analysis Summary Thus, the screening analyses above show that no new shadow from the project would fall on any of the four subject Proposition K open spaces Willie Wong Playground, Justin Herman / Embarcadero Plaza II, or Portsmouth Square during any Proposition K times of day or days of the year. The ESA analysis showed that for the Woh Hei Yuen Recreation Center and Park, shadow from the project alone, considering only the distance and elevation difference, and regardless of the intervening buildings, could not reach the open space during Proposition K times during the year. Furthermore, this analysis also found that, of the instances in which the project could cast a shadow that would reach into the Willie Wong Playground, the Justin Herman / Embarcadero Plaza II, or Portsmouth Square, no new shadow would occur during Proposition K times of the day, because the existing intervening buildings would block the new shadow from reaching into those open spaces. Stated another way, existing buildings would block the shadow from the project from reaching these open spaces during Proposition K hours. Therefore, the project would have no shadow impact on these open spaces, within the meaning of Planning Code Section 295(b) and no further analysis of shadow impacts is required for these parks. 8 By inspection of the digital model, it is also clear that no part of the project building would be visible from any point within the Portsmouth Square open space. This is a corollary to the condition that the Washington Montgomery Tower, the Transamerica Pyramid, and the 601 Montgomery Street highrise tower form a barrier that would prevent any project shadow from reaching Portsmouth Square. 555 Washington Street Project 13 of 19 March 30, 2009

14 TABLE 3: SHADOW SCREENING, PORTSMOUTH SQUARE Date Time Altitude Angle Azimuth Angle Shadow Length Shadow Long Enough to Reach Park? 21-Jun 6:46.8 a.m ,124 yes 28-Jun 6:48.6 a.m ,124 yes 5-Jul 6:52.2 a.m ,112 yes 12-Jul 6:56.4 a.m ,087 yes 5-Jul 7:00 a.m ,822 yes 12-Jul 7:00 a.m ,951 yes 19-Jul 7:01.2 a.m ,063 yes 28-Jun 7:15 a.m ,391 yes 21-Jun 7:15 a.m ,355 yes 5-Jul 7:15 a.m ,448 yes 12-Jul 7:15 a.m ,528 yes 26-Jul 7:07.2 a.m ,040 yes 19-Jul 7:16.2 a.m ,596 yes 28-Jun 7:30 a.m ,154 yes 5-Jul 7:30 a.m ,193 yes 26-Jul 7:15 a.m ,768 yes 12-Jul 7:30 a.m ,247 yes 19-Jul 7:30 a.m ,315 yes 2-Aug 7:12.6 a.m ,006 yes 21-Jun 7:45 a.m yes 2-Aug 7:15 a.m ,920 yes 5-Jul 7:45 a.m ,006 yes 26-Jul 7:30 a.m ,397 yes 12-Jul 7:45 a.m ,047 yes 19-Jul 7:45 a.m ,095 yes 21-Jun 8:00 a.m no 2-Aug 7:30 a.m ,502 yes 9-Aug 7:19.2 a.m ,983 yes 12-Jul 8:00 a.m yes 26-Jul 7:45 a.m ,154 yes 19-Jul 8:00 a.m yes 28-Jun 8:15 a.m no 9-Aug 7:30 a.m ,632 yes 5-Jul 8:15 a.m no 2-Aug 7:45 a.m ,221 yes 12-Jul 8:15 a.m no 26-Jul 8:00 a.m yes 16-Aug 7:25.2 a.m ,951 yes 19-Jul 8:15 a.m no 16-Aug 7:30 a.m ,795 yes 9-Aug 7:45 a.m ,305 yes 2-Aug 8:00 a.m ,026 yes 26-Jul 8:15 a.m yes 16-Aug 7:45 a.m ,413 yes 9-Aug 8:00 a.m ,088 yes 23-Aug 7:31.8 a.m ,930 yes 2-Aug 8:15 a.m yes 16-Aug 8:00 a.m ,158 yes 23-Aug 7:45 a.m ,534 yes 9-Aug 8:15 a.m yes 2-Aug 8:30 a.m no Source: ESA, of 19

15 Proposition K Impacts Methodology To evaluate the year-round Proposition K impact on Maritime Plaza and Sue Bierman Park, CADP conducted a quantitative analysis to assess and calculate the net new shadow. This methodology, which uses date, time, and sun angle data reviewed and accepted by the City, 9 calculates using computer models existing and new shadow and sunlight hours for 26 sample dates between July and December (because the sun s path from January through June essentially mirrors its path from July through December, only six months of modeling data are produced 10 ). Subsequently, the shadow coverage quantities are extrapolated to annual figures by multiplying by an annualization factor returning a yearly total of new shadow hours produced by the proposed project, the office variant, and the code-complying alternative as well as existing sun and shadow hours prior to any project or alternative/variant and annual available sunlight hours for each park. To determine the sunlight benefit of the Redwood Park conveyance, the above-described model was used to determine the amount of remaining sunlight on Redwood Park while taking into consideration all shadow areas on Redwood Park after completion of the project, the office variant, or the code-complying alternative. Proposition K Shadow Impacts Project Shadow The project proposes a 390 foot-tall residential tower with mechanical reaching a height of 425 feet that would add new shadow to Maritime Plaza and Sue Bierman Park in the afternoon hours. Using the methodology described above, on the summer solstice (June 21) when the sun is highest and shadows are shortest, new shadow on Maritime Plaza would reach the park around 4:45 p.m., peak around 5:45 p.m., and recede behind the existing building shadows by 7:15 p.m. This pattern would continue throughout the period of impact with new shadow occurring as early as 4:30 in late July and throughout August and reaching the park later and later through September. The new shadow would linger until just after 7:00 p.m. in August. By late August, the days grow shorter and the duration of the new shadow also begins to reduce. By September 20th, the project shadow would reach Maritime Plaza around 6:00 p.m. and recede before 6:15 p.m. The maximum area of new shadow, recorded for the project was 15,464 square feet which would occur on August 8th at 5:30 p.m. (see Figure 5). According to the analysis, the majority of new shadow produced by the project was found to occur on Maritime Plaza from June 21st through mid September. In general, the new shadow would reach Maritime Plaza along the northwestern portion of the park in mid- to late- afternoon and sweep southward though the remaining hours of sunlight. Due to the Alcoa (One Maritime Plaza) building s location in the middle of Maritime Plaza, the project s new shadow would be limited to a narrow strip along the northern edge of the eastern half of the park. New shadow resulting from the project would also fall on western block of Sue Bierman Park from September 6 through September 20, between 5:45 p.m. and 6:15 p.m. In addition, project shadow 9 The Annual Available Sunlight (AAS) calculation using the CADP model, which is based on the annualized sun of all 26 sample dates, results in a larger number than the AAS based on the City s AAS factor. CADP adjusts the AAS analysis by the percentage difference in the two factors to accurately establish the existing and new annual shadow square-foot hours based on the CADP sample dates. 10 Reference to specific months throughout this memorandum includes those months at the opposite end of the year where the sun/shadow tracks are approximately equal. 555 Washington Street Project 15 of 19 March 30, 2009

16 Figure 5: Maximum Project shadow on Maritime Plaza, August 9, 5:30 p.m. Existing shadow is grey and project shadow is black Source: CADP, 2008 would fall on the eastern portion of Sue Bierman Park on September 13th at 6:00 p.m. through September 20th between 6:00 and 6:15 p.m. Because the sun path in the first half of the year mirrors the sun s path in the second half of the year, the project would also cast similar shadow on this park during March. The maximum area of new shadow, recorded for the project was 8,775 square feet which would occur on September 20 at 6:15 p.m. The new shadowing on this park would be limited to a narrow sliver along the northern edges of the park in areas adjacent to the sidewalk (see Figure 6). Figure 6: Maximum Project Shadow on Sue Bierman Park, September 20 at 6:15 p.m. Existing shadow is grey and project shadow is black. Source: CADP, Washington Street Project 16 of 19 March 30, 2009

17 The project would increase shadow coverage on Maritime Plaza by about 2,822,513 shadow-foothours, which is approximately 0.88 percent of the total potential sunlight, as recorded by the 1989 memorandum. The addition of the project would also increase shadow coverage on Sue Bierman Park by about 43,682 shadow-foot-hours, or less than percent of the total potential sunlight. The project would also create 21,441,397 annual SFH of new sun with the addition of Redwood Park which would serve as compensation for the loss of sunlight on Proposition K properties. Combined, the project would cast up to 2,866,188 annual SFH of new shadow on Recreation and Park Department open spaces in the Downtown area while creating 21,441,397 annual SFH of sun, an overall increase of over 18.5 million SFH of sun (see attached tables). As a result, the proposed project would add about seven and one-half times more annual solar year hours of sunlight than shadow hours produced by its implementation. Office Variant Shadow The office variant proposes a 357-foot-tall tower with a mechanical penthouse rising to 390 feet that would add new shadow to Maritime Plaza and Sue Bierman Park in the afternoon hours. Although this variant would follow a similar shadowing pattern as the project, the shadow effects would be slightly changed as the office structure would be shorter and wider. New shadow from this office variant would still fall on the portion of Maritime Plaza west of the Alcoa (One Maritime Plaza) building from June 21st through September 20th. 11 However, no new shadow would be cast prior to 4:30 p.m. on any day throughout the year. Shadows would peak in size around 6 p.m. According to the analysis, the majority of new shadow produced by the office variant was found to occur on Maritime Plaza from June 21st through mid September. In general, the new shadow would reach Maritime Plaza along the northwestern portion of the park in mid- to late- afternoon and sweep southward though the remaining hours of sunlight. Due to the Alcoa building s location in the middle of Maritime Plaza, the office variant s new shadow would be limited to a narrow strip along the northern edge of the eastern half of the park. The maximum area of new shadow would occur on August 2 at 6:00 p.m. when approximately 15,898 square feet of new shadow would fall on Maritime Plaza. New shadow resulting from the office variant would also fall on the western block of Sue Bierman Park from September 13 through September 20 between 5:45 p.m. and 6:15 p.m. In addition, its shadow would fall on the eastern portion of Sue Bierman Park on September 20th between 6:00 p.m. and 6:15 p.m. Because the sun path in the first half of the year mirrors the sun s path in the second half of the year, the project would also cast similar shadow on this park during March. The maximum area of new shadow on Sue Bierman Park, recorded for the office variant was 8,410 square feet which would occur on September 20 at 6:15 p.m. The new shadowing on this park would be limited to a narrow sliver along the northern edges of the park in areas adjacent to the sidewalk, similar to the shadow for the project (see Figure 6, above). Similar to the project described above, the office variant would increase shadow coverage on Maritime Plaza by about 2,395,158 shadow-foot-hours, which is approximately 0.75 percent of the total potential sunlight, as recorded by the 1989 memorandum. The addition of the office variant would 11 Because the path of the sun in the first half of the year mirrors the sun s path in the second half of the year, the project would also cast new shadow, in the same location and area shaded, in the late afternoon from mid-march through June. 555 Washington Street Project 17 of 19 March 30, 2009