Draft Project Impact Report - Boston Redevelopment Authority

Exeter Residences/888 Boylston
BRADA Software
Viewpoints and Study Scenarios
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Environmental.docx
The BRADA 1 program was developed in 1985 by the Massachusetts Institute of
Technology to estimate the pedestrian’s view of the sky plane taking into account the
massing and building materials used. The software approximates a pedestrian’s
view of a site based on input parameters such as: location of viewpoint, length and
height of buildings and the relative reflectivity of the building facades. The model
typically uses the midpoint of an adjacent right-of-way or sidewalk as the analysis
viewpoint. Based on these data, the model calculates the perceived sky plane
obstruction and provides a simple graphic depicting the analysis conditions.
The model inputs used for the study presented in this PNF are based on site
observations and an existing conditions survey prepared by Vanasse Hangen
Brustlin, VHB and schematic design plans prepared by CBT and Elkus/Manfredi
Architects, project architects. As described above, the BRADA software considers the
relative reflectivity of building facades when calculating perceived daylight
obstruction. Highly reflective materials are thought to reduce the perceived sky
plane obstruction when compared to non-reflective materials. For the purposes of
this study, the building facades are considered non-reflective, resulting in a
conservative estimate of daylight obstruction.
In response to comments received from the NPC/PNF filing, four viewpoints were
selected for the daylight analysis. Additional interior courtyard locations were
requested but due to program limitations they were analyzed as perspectives and
can be found in Chapter 3, Urban Design.
The four viewpoints used for this daylight analysis are depicted on Figure 5-28:
Viewpoint #1: Exeter Street - located on the centerline of Exeter Street,
centered on the façade of the proposed Exeter Residences.
Viewpoint #2: Gloucester plaza – located between the Gloucester and Lord &
Taylor buildings, focused on the western façade of the proposed Exeter
Residences from a point equally spaced between the existing buildings.
Viewpoint #3: Boylston Street - located on the centerline of Boylston Street,
centered on the façade of the proposed 888 Boylston.
Viewpoint #4: Fairfield plaza – located between the Fairfield and Prudential
Mall buildings, centered on the eastern façade of the proposed 888 Boylston.
Each viewpoint was analyzed for three study scenarios:
1 Boston Redevelopment Authority Daylighting Analysis (BRADA) Software: Harvey Brian and Susan Stuebing,
Massachusetts Institute of Technology, Cambridge, Massachusetts (1985).
DRAFT - Environmental Protection 5-28