point cover jan 13 - Boston Redevelopment Authority

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Expanded_PNF\04_Environmental_FINAL.do
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Vanasse Hangen Brustlin, Inc.
The Point, Boston
reflected glare from the viewers’ viewing directions. Clear, tinted, color, fritted and/or reflective glazing
systems’ reflectance characteristic, or the outward reflectance, varies from seven percent to 55 percent,
respectively; however the amount of reflected sun that reaches the surface of interest varies based on the sun
intensity, position, and the total inter-reflection within the surfaces in a given site. Based on glazing studies,
various glass samples were selected by the project architect, design team and supported by the MEP team for
the energy use of the building given their ASHRAE energy compliance requirement for this climatic zone
(zone-5) not to exceed SHGC of 0.40. The characteristics of these glass samples were evaluated for their solar
and daylighting performance. The results show that there are no adverse thermal or visual impacts on the
surrounding spaces and/or on specifically selected points of interest using glass samples with an outwardly
visible reflectance below 15 percent and solar reflectance not exceeding 35 percent based on conditions (refer
to Appendix D for these conditions).
The results show that the currently proposed building design (i.e., building geometry with selected glazing
system, their specific detail as designed within the elevations, and the associated curtain walls) fully comply
with a typical city code ordinance on building façade-related solar glare. The proposed building and
landscape within the Project Site and the associated specifications on selected glazing systems with their
specific solar and optical characteristics will mitigate the reflected glare from the viewers’ viewing directions.
The proposed building will not produce reflected illumination, sky-reflected glare, or direct illumination
across any lot line from a visible source of illumination of such intensity to cause visual discomfort to
pedestrian traffic (i.e., public walking) on the adjacent property or within the property (i.e., pedestrians or
building occupants entering and leaving the building site or employees/public during regular daytime
working hours). Additionally, the building will not result in visual discomfort problems, such as the traffic
hazard, or detract from the use or enjoyment of adjacent surrounding property. The results show that the
average glare index and or glare factor does not exceed the 50 scale which is equal to just admissible rating in
accordance with the Illuminating Engineering Society of North America (IESNA) Standards, 1 the USA
lighting authority, and the International Commission on Illumination (CIE). 2
Solar Heat Build-Up
The solar heat reflected from the building surfaces would not impact the cooling load of the building itself or
the adjacent buildings. In most cases, a large part of incoming solar rays are shielded by the building, shading
other adjacent buildings at various times from sun high intensities or under the low solar altitude conditions.
Solar Glare Mitigation for Bird Safety
The Project is designed with a series of angled facades along its major axis (along Brookline and Boylston).
Over the length of the façade, the angles change as much as eight degrees. This change in angle helps
disconnect visual reflections from the building’s surface for passing birds. Additionally, these small, angled
facades are framed by a pattern of opaque surface. Therefore, if an approach pattern created an angle where
reflections could carry from one surface to another, the opaque surfaces would disconnect this interpretation
and serve to alert birds of the hazard.
1 www.iesna.org
2 www.cie.co.at
4-14 Environmental Protection