Draft Project Impact Report - Boston Redevelopment Authority

Overview
Exeter Residences/888 Boylston
Methodology
\\Mabos\projects\09916.00\docs\Permits\DPIR\Text\DPIR Chapter 5
Environmental.docx
Major buildings, especially those that extend above their surrounding, often cause
increased local wind speeds at the pedestrian level. Typically, wind speeds increase
with elevation above the ground surface. Taller buildings intercept these faster winds
and deflect them down to the pedestrian environment. The funneling of wind
through gaps between buildings and the acceleration of wind around corners of
buildings may also cause a localized increase in wind speed. Conversely, if a
building is surrounded by others of equivalent height, it may be protected from
prevailing upper-level winds, resulting in no substantial changes to the local
pedestrian-level wind environment. The most effective way to assess potential
pedestrian-level wind impacts around a proposed new building is to conduct scale
model tests in a boundary layer wind tunnel. For that reason, RWDI has conducted
the wind tunnel tests which are reported in this section.
The consideration of wind in planning outdoor activity areas is important since high
winds in an area tend to deter pedestrian use. For example, winds should be light or
relatively light in areas where people would be sitting, such as outdoor cafés or
playgrounds. For bus stops and other locations where people would be standing,
somewhat higher winds can be tolerated. For frequently used sidewalks, where
people are primarily walking, stronger winds are acceptable. For infrequently used
areas, the wind comfort criteria can be relaxed even further. The actual effects of
wind can range from pedestrian inconvenience, due to the blowing of dust or other
loose materials in a moderate breeze, to severe difficulty with walking due to the
wind forces on the pedestrian.
Information concerning the site and surroundings was derived from site
photographs, the BRA’s 3D model of the area, information on surrounding buildings
supplied by the architects and site plans and elevations of the proposed development
provided by the design team.
The following configurations were simulated in the wind tunnel:
Existing Conditions – includes existing buildings on and around the site;
155-Feet Zoning Height – includes Exeter Residences and 888 Boylston at 155
feet zoning height on and around the existing site surroundings.
Proposed Program – includes the design of 28 stories and 320’ in height for
the Exeter Residences and 19 stories and 265’ in height for 888 Boylston in
and around the existing site surroundings.
DRAFT - Environmental Protection 5-4