Attachment E: CADP Design Shadow Analysis

Transcription

1 Attachment E: CADP Design Shadow Analysis

2 June 6, 2016 TO: Don Lewis San Francisco Planning Department 1650 Mission Street, Suite 400 San Francisco, CA SUBJECT: 2060 Folsom Street 17 th & Folsom Park Shadow Analysis Case No PPA OVERVIEW The Planning Department prepared an initial shadow fan that indicated the proposed project at 2060 Folsom Street may cast a shadow on the future 17 th & Folsom Park, a property that is currently under the jurisdiction of the San Francisco Recreation and Park Department ( Recreation and Park Department ). Under Planning Code Section 295, a shadow analysis is required to measure and quantify any potential shadow impact of the proposed project on the 17 th & Folsom Park since the proposed project is over 40 feet in height and the 17 th & Folsom Park is/will be within the jurisdiction of the Recreation and Park Department. Construction on the 17 th & Folsom Park commenced in March 2016 with an expected completion date of early/mid The following is a summary of CADP s findings. BACKGROUND ON PLANNING CODE SECTION 295 Planning Code Section 295 was adopted in 1985 in response to voter-approved Proposition K which required Planning Commission disapproval of any structure greater than 40 feet in height that cast a shadow on property under the jurisdiction of the Recreation and Park Department, unless the Planning Commission found the shadow would not be significant. To implement Planning Code Section 295 and Proposition K, the Planning Commission and Recreation and Park Commission in 1989 jointly adopted a memorandum establishing qualitative criteria for evaluating shadow impacts as well as Absolute Cumulative Limits ( ACLs ) for certain parks. ACLs are shadow budgets that establish absolute cumulative limits for additional shadows expressed as a percentage of Theoretically Available Annual Sunlight ( TAAS ) on a park with no adjacent structures present. To date, ACL standards have been established for fourteen (14) downtown parks. The 1989 Memorandum sets forth qualitative criteria to determine when a shadow would be significant as well as information on how to quantitatively measure shadow impacts. Qualitatively, shadow impacts are evaluated based on (1) existing shadow profiles, (2) important times of day, (3) important seasons in the year, (4) location of the new shadow, (5) size and duration of new shadows, and (6) the public good served by buildings casting a new shadow. Quantitatively, new shadows are to be measured by the additional annual amount of shadow-square foot-hours as a percent of TAAS. Where an ACL has not been adopted for a park, the Planning Commission s decision on whether a structure has a significant impact on property under the jurisdiction of the Recreation and Park Department is based on a review of qualitative and quantitative factors. Where an ACL has been adopted for a park, the Planning Commission must, upon recommendation of the General Manager of the Recreation and Park Department and in consultation with the Recreation and Park Commission, adopt a resolution raising the ACL for additional shadow on the park. A determination to raise an ACL for a park is also based on qualitative factors and whether the additional shadow cast would have an adverse impact on the park. 1

3 PROPOSED PROJECT Site Description and Present Use The site of the proposed project is 2060 Folsom Street in San Francisco, California (Assessor s Lots 031, Block 3571). It is located between Shotwell Street and Folsom Street, near 17 th Street. The project site is currently developed with a surface parking lot. The property is currently zoned Public (P) and as part of the project approvals will seek a rezoning to Urban Mixed Use (UMU). Surrounding Properties The project site is located in the Mission neighborhood and is almost entirely surrounded by industrial buildings and commercial buildings with some nearby residential buildings. Along Folsom Street, 17 th Street, and Shotwell Street are single and two-story commercial and warehouse buildings including automotive repair and plumbing shops, with one single family residential structure on Shotwell Street. The future 17 th and Folsom Park will be immediately adjacent to the project along 17 th Street between Shotwell Street and Folsom Street. An area map is included as Figure 1. 2

4 Figure 1. AREA MAP SHOWING PROJECT SITE AREA and FUTURE 17 TH & FOLSOM PARK) Proposed Project Folsom Housing, L.P. The 29,075 square-foot project site is located between Folsom Street and Shotwell Street near 17 th Street. The project sponsor is a collaboration between the Mission Economic Development Agency and Chinatown Community Development Center and the development proposes to demolish the existing surface parking lot and develop a 85-foot-tall (94-foot-tall with elevator penthouse), 9-story building containing 127 units of 100% affordable housing. The proposed 165,350 square foot building would include 5,000 square feet for child care, 10,000 square feet for on-site supportive services and 1,000 square feet for a café/retail use. The project would be oriented towards families with a mixture of 2 bedroom units and 3 bedroom units, and would include transitional age youth units. No off-street parking would be constructed though the project will include 107 Class I bicycle parking spaces. Because the project is greater than 40 feet in height, a shadow analysis under Proposition K is required. Images of the proposed building are included below in Figure 2. 3

5 Figure 2. Conceptual Sketch of South Facing Elevation 17 th & FOLSOM PARK Since 2010 planning has been underway for the development of the 17 th & Folsom Park. The future park will be immediately adjacent to the proposed project and will front Shotwell Street, Folsom Street and 17 th Street. The 0.73-acre park will have a mixture of seating areas, a community garden and children s play area alongside an adult fitness area. The 17 th & Folsom Park hours are unknown at this point. A conceptual image of the 17 th & Folsom Park is included below as Figure 3 4

6 Figure th & Folsom Park Site Plan 5

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8 SHADOW METHODOLOGY AND RESULTS CADP prepared a shadow analysis of the proposed project on the under construction 17th & Folsom Park. The analysis conducted was based on a June 21st start date that ran through December 21st to provide a sample of representative sun angles throughout the solar year. The solar year is from June 21st through December 21st. The sun angles during the other side of the calendar year, or December 22 nd through June 20th, mirror the sun angles presented during the sample time frame. As the angles are mirrored, an analysis of the other time period is not conducted and instead a multiplier is used to put the sample results into calendar year units. Using a multiplier does not change the percentages. For purposes of the analysis, time was measured in decimal hours at 15 minute intervals from sunrise plus 1 hour to sunset minus 1 hour. Shadow impacts are calculated based on square-foot hours recorded. To ensure a complete and accurate description of the proposed project s potential shadow impacts, this analysis identifies the days when shadow cast by the proposed project: (1) would be at its largest size by area, and (2) would result in the overall greatest shadow impacts in terms of size and duration (i.e., the maximum net new shadow as measured in square foot hours.) 17 th & Folsom Park The under construction 17 th & Folsom Park has approximately 117,774, square feet hours ( sfh ) of Theoretically Available Annual Sunlight ( TAAS ), which is the amount of theoretically available sunlight on the park annually if there were no shadows from structures, trees or other facilities. Shadows would exist on the future park in the morning, late afternoon, and evening during various times of year. The existing shadow load is 1,706, sq ft hrs annually. This is approximately 1.448% of the total TAAS for the 17 th & Folsom Park. The proposed project would add 1,643, sfh of shadow on the 17 th & Folsom Park. This is a 1.395% increase in shadow as a percentage of TAAS. Existing shadows on the future park at 17 th and Folsom occur only in the early morning from the building along Folsom between 17 th and 18 th Streets and the late afternoon from the buildings along Shotwell between 17 th and 18 th Streets. These shadows are limited to the western and eastern edge of the park respectively. New shadow would be cast by the proposed project in the summer in the early mornings and evenings with all shadows gone no later than 8:30 AM and not returning until 5:15 PM and lasting until approximately sunset. The longest duration of new shadow would be approximately 4 hours 19 minutes. All new shadow cast occurs in the early morning hours or in the evening hours, periods of low park use. 1 The largest shadow occurs in and around the children s play area and community garden in the late afternoon. Shadow diagrams showing the location of the potential new shadow is included in Exhibit A. An excel spreadsheet summarizing the findings of the shadow analysis is included in Exhibit B. The maximum net new shadow would occur on June 21 st and contribute 21,795 square foot hours. On this day, the proposed project would cast new shadow on the future 17 th & Folsom Park for approximately 4 hours and 19 minutes from 6:46 AM to approximately 8:30 AM (1 hour 50 minutes) and again from approximately 5:15 PM to 7:36 PM (2 hours 29 minutes). The net new shadow load on June 21 st would be approximately 21,795 sfh and would be localized to the northwest corner of the park in an area designated for the seated wall, paths and garden support area in the mornings and in the northeast corner of the park in the evenings in the area designated for the children s play area and adult fitness equipment area. Shadow would occur on the designated community garden area during both the morning and evening times. 1 For example, recent observations conducted by CADP at Parque Ninos Unidos located approximately 6 blocks away indicates that park playground use on weekdays typically peaks in the hours after school at approximately 2:00pm and the use begins to dissipate at 5:00 pm with a continued decline in playground use into the evening hours. Use is low in the early morning hours and is occupied mostly by local residents dog walking. 7

9 The largest new shadow by area would also occur on June 21 st at 7:36 PM. At its maximum, the new shadow area would be 11,114 square feet. The maximum morning new shadow would occur on June 21 st at 6:48 AM, 1 hour after sunrise. A figure showing the maximum net new shadow day and largest shadow by area day is included below in Figure 4. The maximum morning shadow by area is shown in Figure 5. 8

10 Figure 4. Maximum Net New Shadow and Largest Shadow by Area Day with the Future Park listed as Existing. 9

11 Figure 5. Maximum Net New Shadow by Area during the Morning with the Future Park listed as Existing. 10

12 SHADOW EVALUATION 17 th & Folsom Park Quantitative Criteria Proposed Annual Available Sunlight The existing shadow load for the 17 th and Folsom Park is approximately percent of the total TAAS. The proposed project would increase the total percentage of TAAS by percent. Table 1 is a summary of those findings. Table 1 SUMMARY OF RESULTS (17 th & Folsom Park) Annualized net new shadow 1,643, sfh Theoretical Annual Available Sunlight 117,774, sfh TOTAL New Shadow as a Percentage of TAAS 1.395% Annualized Existing Shadows on Park 1,706, Percentage of Existing Shadow as a Percentage of TAAS 1.448% TOTAL New + Existing Shadow as a Percentage of TAAS 2.844% Qualitative Criteria Time of Day (morning, mid-day, afternoon) Important Times of Day The under construction 17 th & Folsom Park is relatively flat with a mixture of seating areas, a community garden and children s play area alongside an adult fitness area. The northeast corner and the northwest corner of the park, consists of both the seating areas and the active play areas. These areas are expected to be at low use from 6:48 AM to 8:30 AM when and from 5:30 PM to sunset. 2 While the proposed project casts new shadow on the 17 th and Folsom Park, the shadow is cast either in the early morning hours or early evening hours. Time of Year (Spring, Summer, Fall, Winter) Important Times of Year The 17 th & Folsom Park will likely have active use throughout the year. San Francisco has a temperate climate that allows outdoor recreational spaces to be used year round. Based on San Francisco s historic weather patterns, the important times of year for the 17 th & Folsom Park, when individuals are more likely to use the open areas, are spring and fall which historically have the most sunshine and lowest levels of rain and/or fog. The proposed project would cast new shadow on the 17 th & Folsom Park in the early morning hours and the early evening hours mostly in the summer. Size of Shadow 2 For example, recent observations conducted by CADP at Parque Ninos Unidos located approximately 6 blocks away indicates that park playground use on weekdays typically peaks in the hours after school at approximately 2:00 PM and the use begins to dissipate at 5:00 PM with a continued decline in playground use into the evening hours. At Parque Ninos Unidos, children are rarely present before 8:30 AM with parents and toddlers appearing after 8:30 AM. 11

13 At its maximum, the new shadow area would be 11,114 square feet. This shadow occurs at 7:36 PM on June 21 st when the park is presumably at its lowest point of use or possibly even closed as most parks under the jurisdiction of the Recreation and Park Department close at sunset. As this is a future park, it is presumed that the hours of the future park will be consistent with that policy. Duration of Shadow Shadows from the project would occur only during the summer months from April 5 through to September 6 th. At its shortest, new shadow would be cast for 8 minutes and 24 seconds on September 6 / April 5, and at its longest, new shadow would be cast for 4 hours and 19 minutes on June 21. On that day shadows would be cast approximately 1 hour 50 minutes from 6:46 AM (Sunrise +1hr) to 8:30 AM and then again for approximately 2 hours 29 minutes from 5:15 PM to 7:36 PM (Sunset -1hr). The average shadow when the park receives new shadow from the project during both morning and evening would be approximately 2 hours 37 minutes. The park would not receive any new shadow from the project from 8:45 AM to 5:00 PM at any time throughout the year. Location of Shadow: Morning (6:46 AM to 8:30 AM April 19 th to August 23 rd ) The proposed project would cast new shadow on the northwest corner of the park during the morning hours from 6:46 AM (Sunrise +1hr) until approximately 8:30 AM. The areas affected by the early morning shadows would include the Community Garden, Access Entry for the proposed project, Flexible Space and Community Garden Education Area, Operations and Garden Support Area, portions of the Performance Space, Outdoor Classroom and adjoining Arbor, Seating Wall and Pathways. Location of Shadow: Evening (5:15 PM to 7:36 PM April 5 th to September 6th) The proposed project would cast shadow on the northeastern corner of the park during the evening hours from approximately 5:15 PM to 7:36 PM (Sunset -1hr). The area affected by the evening shadows would primarily include the Community Garden, Children s Play Area and Adult Fitness Equipment Area. * * * * * * Given its location directly adjacent to the future park, a no new shadow alternative would be less than a building of 40 feet in height. * * * * * * Please direct questions regarding this report directly to Adam Noble. Regards, Adam Noble President 12