SITE AND BUILDING INFORMATION. March 28, 2018

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1 March 28, 2018 Mr. Carlos Ramirez Project Manager YORK Developments 303 Richmond St, Suite 201 London, ON N6B 2H8 Re: Preliminary Pedestrian Wind Study 131 King Street - London, ON RWDI Project Dear Mr. Ramirez, Rowan Williams Davies & Irwin Inc. (RWDI) has prepared this Preliminary Wind Report to present our opinion on the potential pedestrian wind conditions on and around the proposed development at 131 King Street in London, Ontario. Our findings are based on a qualitative assessment of the wind conditions in the context of the local wind climate and our expert understanding of wind flows around buildings. This Preliminary Wind Study is required by the City of London in support of the Zoning Bylaw Amendment submission for this project. A more detailed study involving scale model tests in a boundary-layer wind tunnel will likely be required for the Site Plan Approval to quantify these wind conditions and, if necessary, develop wind control solutions. SITE AND BUILDING INFORMATION The proposed development will be located on the south side of King Street between Talbot Street and Richmond Street in London, Ontario (see Image 1). The site is currently a surface parking lot. It is immediately surrounded by low-rise buildings in all directions. Surrounding buildings farther away from the site are generally low-rise with groups of high-rise buildings to the east through north to west of the site. Based on the drawings received by RWDI on March 7, 2018, the proposed development will include a mixed-use 30-storey tower with the ground-level restaurant/retail/service, four levels of above-ground parking, and 25 levels of residential units (see Image 2). The main entrance to the building and the entrance to the commercial area are located along the north façade on King Street. Other pedestrian areas include public sidewalks along King, Talbot, York and Richmond Streets, a laneway on the west side of the building, a surface parking lot on the south side of the building, and outdoor amenity areas at Level 6 and on the roof top of the proposed tower.

2 Image 1: Aerial View of the Development Site and Surroundings (Photograph Courtesy of Google TM Earth) Image 2: North View of Proposed Development WIND DATA Long-term wind statistics recorded at London International Airport were analyzed for the summer (May through October) and winter (November through April) seasons (see Image 3 on the next page). This is the nearest weather station with long-term, reliable wind data. When all winds are considered (regardless of speeds), winds from south, south-southwest, west through northwest and east directions are predominant during summer. During winter, winds from the southwest through northwest and east directions are predominant. Strong winds of a mean speed greater than 30 km/h (yellow and red bands) occur more often in the winter than in the summer, and they are typically from the east and southwest through west directions. PEDESTRIAN WIND ASSESSMENT To provide an opinion on the overall wind conditions expected around the proposed development, RWDI reviewed the long-term meteorological data for the area, drawings and renderings of the proposed development, and information regarding the surroundings. These data, in conjunction with our engineering judgement, allow us to predict the expected wind conditions as outlined below (use plans in Image 4 for reference). Project # Page 2

3 Wind Speed (km/h) Probability (% Summer Wi Calm > Summer (May through October) Winter (November through April) Image 3: Directional Distribution of Winds Approaching London International Airport ( ) Image 4: Reference Plans and Elevation The proposed tower is considerably taller than its immediate surroundings and therefore is exposed to the prevailing winds in all directions. Taller buildings tend to intercept the stronger winds at higher elevations and redirect them down to the ground level. Such a downwashing flow (see Image 5a) is the main cause for increased wind activity around tall buildings at grade level. Project # Page 3

4 Tower setbacks on a podium and adjacent low buildings to the east and west will reduce the direct impact of downwashing wind flows at grade. However, higher wind speeds are expected on the terraces at the podium level (see Image 5b). Image 5a: Downwashing Flow Image 5b: Downwashing Flows on to a Podium The addition of the proposed development will increase the wind activity on King Street sidewalks (Locations A in Image 4), but the resultant wind conditions are generally expected to be comfortable for the intended use of sidewalks. Wind conditions on sidewalks along York, Talbot and Richmond Streets are not expected to be altered by the proposed development due to their farther distances from the proposed development. The main entrance to the tower and the entrance to the commercial area are located along the north façade on King St (Locations B1 and B2, respectively). The main entrance is recessed from the north façade and has a vestibule, which is a positive design feature, as it will provide a space for pedestrian to take shelter during high wind events. Also, the 5-storey podium is expected to keep winds accelerating down the building away from the ground and the entrances along this facade. There is also a canopy structure along the north building façade above these entrances that will provide additional wind protection. As a result, wind speeds at the main entrance are expected to be comfortable throughout the year. The commercial entrance (Location B2) is at the northwest corner of the building and there is a large gap under the vertical wall structure at the corner that allows winds to accelerate into the entrance area (lower corner diagram in Image 4). The wind conditions at this corner are expected to be uncomfortable from time to time in the winter and may exceed the wind safety criterion. Project # Page 4

5 We recommend extending the wall down to the ground (eliminating the gap) or installing a tall screen or a coniferous planter on the west side of the commercial entrance. Alternatively, the commercial entrance should be relocated northward away from the building corner and recessed from the main façade. Due to the prevailing westerly winds downwashing off the proposed tower, increased wind activity is expected along the west laneway (C in Image 4) and at the part of the parking lot that is close to the tower (Location D). These wind conditions, however, are considered appropriate for the intended use of these areas throughout the year since pedestrians are not expected to stay in these areas for a prolonged period of the time. The podium terraces are located on the north side of the building at Level 6. The east terrace (Location E1 in Image 4) is better sheltered than the west terrace (Location E2) from the prevailing westerly winds. In addition to the proposed perimeter guardrails, horizontal elements such as trellises, canopies and landscaping is recommended for the west terrace (Location E2) for wind control. Wind speeds at the rooftop terrace (Location F in Image 4) are expected to be higher than desired for passive activities in the summer due to its elevation and exposure. Typical wind control solutions would include tall guardrails along the entire perimeter to deflect winds up. Local wind control measures such as screens, trellises and landscaping should be considered for any proposed seating areas. The proposed development has several positive design features such as the 5-storey podium, the recessed main entrance, and the canopy structure along the north façade. Suitable wind conditions are expected at the main residential entrance, along sidewalks and the laneway west of the tower, in the parking lot south of the tower, and on the east podium terrace. Accelerated winds and potentially unsafe conditions during the winter are expected at the northwest corner of the proposed development where the commercial entrance is located. Project # Page 5

6 Higher-than-desired wind speeds are also expected at the west podium terrace and on the rooftop terrace. Mitigation measures have been provided herein to ensure comfortable wind conditions are achieved at these areas. Wind tunnel tests can be conducted to quantify these wind conditions and evaluate the effectiveness of these control measures. The wind tunnel tests, if required, are typically completed in support of the SPA submission. CLOSING We trust this meets your current requirements for this project. Should you have any questions or require additional information, please do not hesitate to contact us. Yours truly, Rowan Williams Davies & Irwin Inc. (RWDI) Hanqing Wu, Ph.D., P.Eng. Technical Director / Principal John Alberico, M.Sc., CCEP, WELL AP Senior Project Consultant / Principal Project # Page 6