31/10/17. October 31, HIP Developments Inc. 700 Rupert Street Waterloo, ON N2V 2B5

Transcription

1 University of Guelph Research Park 150 Research Lane, Suite 105 Guelph, ON, N1G 4T /10/17 Date: To: HIP Developments Inc. 700 Rupert Street N2V 2B5 Re: Cambridge, Ontario Novus Project # Novus Team: Engineer: Specialist: Jenny Vesely, P.Eng. Tahrana Lovlin, MAES, P.Eng. Martin Simmons architects Inc. Novus Ref.: Page 1

2 1.0 INTRODUCTION Novus Environmental Inc. (Novus) was retained by HIP Developments Inc. to conduct a pedestrian wind assessment for the proposed 70 King Street North development in Waterloo, Ontario. This assessment is in support of the Zoning By-Law Amendment (ZBA) application for the project. N 1.1 Existing Development The proposed development is located on the east side of King Street North, on the north half of the block encompassed by King Street North to the west, Bridgeport Road East to the north, Regina Street North to the east and Princess Street East to the south. The site is currently occupied by a lowrise building and a parking lot (Figure 1). Directly surrounding the proposed development are low-rise residential and commercial buildings in all directions. Beyond the immediate surroundings there are low-rise residential buildings to the northwest through northeast to southeast, with a mix of low-rise commercial and residential to the south through west. To the west there is a mix of low and mid-rise residential and commercial buildings. A site visit was conducted by Novus on March 20, 2017 and images are included in Figures 2a through 2d. 1.2 Proposed Development This assessment is based on architectural information dated October 19, The proposed development includes a six-storey podium with two towers atop. Tower A (west side) is 16-storeys tall, plus a mechanical penthouse, for a total height of approximately 63m. Tower B (east side) is 22-storeys tall, with a mechanical penthouse, for a total height of approximately 81m. A site plan can be found in Figure 3. Figure 1: Aerial view of existing site & surroundings Credit: Google Earth Pro, dated April 16, Areas of Interest SITE Areas of interest for pedestrian wind conditions include those areas which pedestrians are expected to use on a frequent basis. Typically these include sidewalks, main entrances, transit stops, plazas and parks. For this particular development, areas of interest include the surrounding sidewalks, all entrances and exits, and the numerous outdoor amenity spaces atop the podium. Novus Ref.: Page 2

3 Figure 2a: Looking southeast at existing site Figure 2c: Looking south, along King Street North, at site Figure 2b: Looking south, along Regina Street North, at site Figure 2d: Looking west along Princess Street East Novus Ref.: Page 3

4 BRIDGEPORT ROAD KING STREET NORTH Tower A Tower B REGINA STREET NORTH Figure 3: Site plan (perspective slightly skewed) Credit: Martin Simmons architects inc. Main / Retail Entrance Emergency Exit Outdoor Terrace (Level 7) Novus Ref.: Page 4

5 2.0 APPROACH A qualitative, numerical analysis has been undertaken, based on our extensive experience in estimating wind flow patterns around buildings, and using a knowledge-based expert system (KBES) developed by Novus. The analysis tool is based on published numerical models and methods, consistent with our experience in modelling wind flows through wind tunnel testing. This qualitative method provides a screening-level estimate of potential wind comfort conditions at the site, and assists with the initial selection of conceptual mitigation measures, where needed. This assessment is based on: A review of the architectural drawings dated October 19, 2017; A review of the existing wind climate in the area, through examining historical climate data; A numerical analysis of predicted pedestrian wind comfort resulting from the additional buildings; and, A comparison of the predictions against established pedestrian comfort guidelines. 2.1 Pedestrian Wind Criteria The wind comfort conditions are discussed in terms of being suitable for certain pedestrian activities and are based on frequencies of predicted wind force. Pedestrian activity, wind chill, clothing, humidity and exposure to direct sun, for example, all affect pedestrian (thermal) comfort; however, these influences are not considered in wind force criteria. There are four categories for wind comfort. Sitting: Intended for cafes, terraces and other amenity spaces. These winds will rustle leaves and can be felt on the face. Standing: Intended for main entrances, transit stops and some outdoor amenity spaces; places where people tend to linger. These winds will disturb hair and cause leaves to move. Leisurely Walking: Intended for sidewalks and other areas pedestrians pass through; this may be difficult to achieve in regions with inherently high winter wind speeds. These winds will move small branches, disarrange hair and raise dust. Fast Walking: Intended for loading facilities, parking lots and other such infrequently used areas. At these wind speeds, trees in leaf begin to move. The comfort criteria are based on certain predicted hourly mean wind speeds being exceeded 5% of the time; this is roughly equivalent to a wind event of several hours duration occurring about once per week. If fast walking cannot be achieved, the area is considered to have Uncomfortable wind conditions. A criterion for wind safety is also reviewed and allows for one strong wind events on an annual basis. When more than one strong wind event is predicted, wind mitigation measures are then advised, especially for frequently accessed areas. The criteria for wind comfort and safety used in this assessment are based on those developed at the Boundary Layer Wind Tunnel Lab of the University of Western Ontario, together with building officials in London, England. They are based broadly on the Beaufort scale and on previous criteria that were originally developed by Davenport. Academic references explaining this approach can be found in Section 6.0. Novus Ref.: Page 5

6 2.2 Wind Climate Wind data recorded at the Region of Waterloo Airport in Breslau, Ontario for the period of 1993 to 2015 were obtained and analyzed to create a wind climate model for the seasonal extremes. Annual and seasonal wind distribution diagrams ( wind roses ) are shown in Figure 4. These diagrams illustrate the percentage of time wind blows from the 16 main compass directions. Of main interest are the longest peaks that identify the most frequently occurring wind directions. The annual wind rose indicates that wind approaching from the southwest through northwest directions are most prevalent, with secondary winds from the east. The seasonal wind roses readily show how the prevalent winds shift throughout the year. Winter Winds (Jan Mar) Spring Winds (Apr-Jun) The directions from which stronger winds (e.g. > 30 km/h) approach are also of interest as they have the highest potential of creating problematic wind conditions, depending upon site exposure and the building configurations. The wind roses in Figure 4 also identify the directional frequency of these stronger winds, as indicated in the figure s legend colour key. On an annual basis, strong winds occur from the southwest through northwest directions. All wind speeds and directions were included in the wind climate model. Summer Winds (Jul Sept) Annual Winds WIND SPEED > 30 km/h < 30 km/h Autumn Winds (Oct-Dec) Figure 4: Wind Roses for the Region of Waterloo Airport ( ) Novus Ref.: Page 6

7 3.0 RESULTS Wind conditions at areas of interest were predicted using Novus proprietary knowledge-based expert system (KBES). The results present a reasonable worst-case assessment of potential wind conditions at the site. Results are presented for the summer and winter seasons, with a graphical representation of the winter results in Figure 5 for grade level areas. Figure 6 presents the predicted summer season conditions on the numerous terraces. There are no predicted safety concerns around the proposed development, in either the Existing or Proposed Configuration. 3.1 Existing Wind Conditions The existing site currently includes a low-rise institutional building and a parking lot. Wind conditions on site, as well as on the surrounding sidewalks, are expected to be comfortable for sitting in both the summer and winter seasons. 3.2 Building Entrances & Exits The main entrance to Tower A is located in the middle of the west facade and is recessed. Wind conditions at the entrance are expected to be comfortable for standing throughout the year. Along the west facade there are two retail entrances and the office entrance (Figure 5). As these entrances are recessed beneath the mass of the podium, we anticipate wind conditions to be conducive to standing in both the summer and winter seasons. The main entrance to Tower B is located in the middle of the east facade and is also recessed (Figure 5). Wind conditions at this entrance are expected to be comfortable for standing in both the summer and winter seasons. Similar wind conditions are anticipated at the emergency exits along the east side of the building. However, at the retail entrance at the northeast corner wind conditions are predicted to be comfortable for standing in the summer and leisurely walking in the winter, as the prevailing westerly winds are directed around the corner of the building by the mass of the tower. At the exit on the north facade, wind conditions are expected to be comfortable for standing throughout the year (Figure 5). These wind conditions are considered suitable for the intended usage. 3.3 Level 7 Terraces On Level 7 of the development, atop the podium, there are numerous terraces (Figure 6). On the office terrace, wind conditions are expected to be comfortable for standing in both the summer and winter seasons. These wind conditions are considered appropriate for the intended usage. Between the towers, on the south portion of the podium, there is an outdoor terrace and garden with reflecting pools (Figure 6). In the summer, wind conditions are predicted to be comfortable for sitting, as the area is sheltered by the mass of the towers. Further to the east, along the south terrace, wind conditions are expected to be conducive to standing in the summer season. In the winter, wind conditions are on the entire south terrace are expected to be comfortable for standing. Novus Ref.: Page 7

8 BRIDGEPORT ROAD Main Entrance Emergency Exit KING STREET NORTH Tower A Tower B REGINA STREET NORTH Predicted Wind Comfort Figure 5: Summary of predicted wind comfort conditions Grade level Worst case Winter season Sitting Standing Leisurely Walking Fast Walking Uncomfortable Novus Ref.: Page 8

9 Tower A Tower B Predicted Wind Comfort Figure 6: Summary of predicted wind comfort conditions Level 7 Terraces Summer Season Sitting Standing Leisurely Walking Fast Walking Uncomfortable Novus Ref.: Page 9

10 On the west terrace, along King Street North, wind conditions in the summer and winter seasons are anticipated to be suitable for standing, again due to the exposure of the area to the prevailing westerly winds (Figure 6). On the north terrace, wind conditions are expected to be comfortable for standing in the summer, especially along the north edge (Figure 6). In the more sheltered area, with the pool, wind conditions are predicted to be comfortable for sitting in the summer season. In the winter, wind conditions on this terrace are generally expected to be suitable for standing. However, near the building corners wind conditions will likely be conducive to leisurely walking, due to the downwashing of northwesterly winds off Tower B on to the podium. On the east terrace (Figure 6), wind conditions are expected to be comfortable for sitting in the summer, as the area is sheltered from the prevailing winds by the mass of the development. In the winter, wind conditions are predicted to be conducive for standing. The usage of landscaping throughout the terraces is a positive design feature, particularly with regards to thermal comfort in the summer. This landscaping should be retained through the design process. These wind conditions are generally considered to be appropriate for the intended usage. Figure 7: Example of wind screen around terrace 3.4 Surrounding Sidewalks With the proposed development in place, the analysis indicated that wind conditions on the surrounding sidewalks of King Street North, Regina Street North, Bridgeport Road and Princess Street are expected to be comfortable for leisurely walking or better throughout the year. The windiest areas in the vicinity are expected to be at the northwest and northeast corners of the development, along the south sidewalk of Bridgeport Road. These wind conditions are considered appropriate for the intended usage. Novus Ref.: Page 10

11 4.0 CONCLUSIONS & RECOMMENDATIONS A qualitative numerical analysis was conducted to estimate the wind comfort conditions associated with the development of the proposed 70 King Street North development in Waterloo. The predicted wind comfort on the site and surrounding sidewalks are considered appropriate for the intended usage throughout the year. Wind conditions on the terraces are expected to be comfortable for the intended usage. Wind conditions in and around the proposed development were predicted to meet the wind safety criterion. No additional analysis is considered necessary. 5.0 ASSESSMENT APPLICABILITY This assessment provides a qualitative overview of the anticipated pedestrian wind comfort conditions on and surrounding the proposed development. Any subsequent alterations to the design may influence these findings, possibly requiring further review by Novus. Should you have any questions or concerns, please do not hesitate to contact the undersigned. Sincerely, Novus Environmental Inc. Jenny Vesely, P.Eng. Intermediate Engineer Tahrana Lovlin, MAES, P.Eng. Specialist Microclimate Novus Ref.: Page 11

12 6.0 REFERENCES Blocken, B., and J. Carmeliet (2004) Pedestrian Wind Environment around Buildings: Literature Review and Practical Examples Journal of Thermal Environment and Building Science, 28(2). Cochran, L. (2004) Design Features to Change and/or Ameliorate Pedestrian Wind Conditions ASCE Structures Conference Davenport, A.G. (1972) "An Approach to Human Comfort Criteria for Environmental Wind Conditions", Colloquium on Building Climatology, Stockholm, September Durgin, F.H. (1997) Pedestrian level wind criteria using the equivalent average Journal of Wind Engineering and Industrial Aerodynamics 66. Isyumov, N. and Davenport, A.G., (1977) The Ground Level Wind Environment in Built-up Areas, Proc. of 4th Int. Conf. on Wind Effects on Buildings and Structures, London, England, Sept. 1975, Cambridge University Press, Isyumov, N., (1978) Studies of the Pedestrian Level Wind Environment at the Boundary Layer Wind Tunnel Laboratory of the University of Western Ontario, Jrnl. Industrial Aerodynamics, Vol. 3, , Irwin, P.A. (2004) Overview of ASCE Report on Outdoor Comfort Around Buildings: Assessment and Methods of Control ASCE Structures Conference Kapoor, V., Page, C., Stefanowicz, P., Livesey, F., Isyumov, N., (1990) Pedestrian Level Wind Studies to Aid in the Planning of a Major Development, Structures Congress Abstracts, American Society of Civil Engineers, Koss, H.H. (2006) On differences and similarities of applied wind criteria Journal of Wind Engineering and Industrial Aerodynamics 94. Soligo, M.J., P.A., Irwin, C.J. Williams, G.D. Schuyler (1998) A Comprehensive Assessment of Pedestrian Comfort Including Thermal Effects Journal of Wind Engineering and Industrial Aerodynamics 77/78. Stathopoulos, T., H. Wu and C. Bedard (1992) Wind Environment Around Buildings: A Knowledge-Based Approach Journal of Wind Engineering and Industrial Aerodynamics 41/44. Stathopoulos, T., and H. Wu (1995) Generic models for pedestrian-level winds in built-up regions Journal of Wind Engineering and Industrial Aerodynamics 54/55. Wu, H., C.J. Williams, H.A. Baker and W.F. Waechter (2004) Knowledge-based Desk-top Analysis of Pedestrian Wind Conditions, ASCE Structures Conference Novus Ref.: Page 12