What to do about high winds 'downdrafting' the face of tall Boston buildings?

stellarfun

Senior Member
Joined
Dec 28, 2006
Messages
4,907
Reaction score
144
Boston, defined by the open sea along its entire eastern edge, consistently records the fastest average wind speeds among major US cities (according to the National Oceanic and Atmospheric Administration). It’s considerably windier than Chicago, notwithstanding the nickname of that metropolis, which originally referred to an alleged penchant for bragging. ....

Boston planners have joined their counterparts from London, Toronto, and San Francisco in paying special attention to street-level wind effects around new development. That means heading off problems early in the design process and making modifications to completed projects when the conditions they help create are too blustery by far for those walking by.

One project is specifically referenced for doing extensive wind studies: Studio Gang's One Kenmore Square. IIRC, the PNF for the Pinnacle explains that the terraced layers that are a feature of the design are intended to reduce wind-effects at the street level.

'Downdrafting' occurs when a single tall building is involved. If several adjacent tall buildings are involved, the increased wind speed at ground level is a modified version of the Venturi effect, known as channeling.
 

Arlington

Moderator
Staff member
Joined
Dec 10, 2011
Messages
4,291
Reaction score
450
I'd say we need more street-level amenities:
1) Tree Canopy
2) Awnings / Entry Cover / Arcades

The same stuff that'd stop the wind from crushing down is also good to protect from rain & sun & ice-fall
 

Zash

New member
Joined
Aug 8, 2019
Messages
24
Reaction score
28
Stuck behind a paywall. Anybody have a summary?
 

stellarfun

Senior Member
Joined
Dec 28, 2006
Messages
4,907
Reaction score
144
Several excerpts:
Boston, defined by the open sea along its entire eastern edge, consistently records the fastest average wind speeds among major US cities (according to the National Oceanic and Atmospheric Administration). It’s considerably windier than Chicago, .....

Another key factor [in wind speed] is the basic nature of urban development in an older city, which creates juxtapositions between new tall buildings and the city’s cozy low-rise neighborhoods — and helps whip up the wind further still.

But have a measure of faith, city planners say. With construction booming and several new towers planned, Boston planners have joined their counterparts from London, Toronto, and San Francisco in paying special attention to street-level wind effects around new development. That means heading off problems early in the design process and making modifications to completed projects when the conditions they help create are too blustery by far for those walking by. “using the technologies that are available, manipulating the architecture to manage the wind … and just be smarter about it.”

Wind tunnels happen because wind travels faster at higher altitudes, hitting the sides of buildings, which act like sails, and rattling down to the street. With nowhere else to go, it finally surges through gaps between buildings, down narrow streets, and around corners, similar to water shooting through the nozzle of a hose. March is historically the city’s windiest month, with speeds averaging around 12.9 miles per hour (again, according to NOAA data). Wind tunnels can easily push gusts beyond 20 miles per hour, which stir up debris, invert umbrellas, and are generally considered uncomfortable. Anything closer to 30 miles per hour and beyond can knock over pedestrians and bicyclists.
....
a number of steps designers and developers can take to head off a wind-tunnel problem: putting the taller parts of buildings on a podium, which absorbs the downdraft; extending canopies at entrances or building overhead trellises; incorporating fins and other surface modulation to add wind-impeding texture to facades; chamfering, or rounding off corners
Reference is made to major problems caused by the 'walkie talkie' building in London. See:

For Toronto, see:

For San Francisco, "San Francisco is reviewing how to best handle street-level wind, as tall buildings such as the Salesforce Tower transform the skyline." I can't find anything more that is specific to the Salesforce Tower.
 

George_Apley

Not a Brahmin
Staff member
Joined
Jan 22, 2012
Messages
4,358
Reaction score
723
Key points from the above Globe article:
  • City planners are working with experts and officials from other cities to mitigate downdrafts and wind tunnels caused by interactions between the wind and tall buildings.
  • Tall buildings clustered together buffer one another and mitigate the ground level wind effects.
  • Analysis during the design stage of buildings is relatively rigorous.
  • Setbacks and other features that break up a façade on buildings are better for wind than featureless or smooth surfaces.
  • Landscaping with the right flora can mitigate ground-level effects.
Everything else was just context and and prose.
 

Top