Shadow Modeling

This digital 3-D model of Boston reveals the shadows cast by new construction

Development East Urbanism

On May 8, Boston’s Planning & Development Agency (BPDA) released a digital 3-D model of the city. Built with GIS and CAD, the map encompasses approximately 129,000 buildings, each roughly outlined to indicate overall massing and height.

According to the Boston Globe, the map was partially inspired by debates surrounding shadows cast on the Boston Commons by new skyscrapers, such as the nearly 700-foot-tall Winthrop Square Tower. The 3-D model uses Boston’s monthly average amount of daylight to effectively represent each building’s impact on citywide light exposure. Areas with dense concentrations of skyscrapers, primarily Downtown Boston, are depicted as casting shadow overs large swaths of the city.

On the map, the function of each building within the city is graphically represented through the use of a color scheme sequenced to Boston’s zoning regulatory framework. Industrial districts, such as Marine Industrial Park, are clearly discernible from residential quarters such as adjacent City Point. Beyond the representation of each individual building’s function, the model outlines the city’s zoning districts, sub districts and special planning areas.

Building uses are visually mapped across the city, such as the differences between Marine Industrial Park and City Point (Boston Planning & Development Agency)

As a coastal city, the BPDA has to accommodate for inevitable rises in sea level. To this end, the model also maps out Boston’s FEMA National Flood Hazard Areas, as well as areas that would be significantly impacted by a 100-year flood of 40 inches or more.

The 3-D model encompasses the entire city, here showing areas prone to flooding (Boston Planning & Development Agency)

Additionally, the model shows Boston’s entire public transport network, university system, and areas subject to urban renewal policies.

While the 3-D model only includes existing buildings and those under construction, the BPDA is hoping to incorporate planned developments into the model to allow for their visualization within a larger urban context.

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