Manulife Financial - John Hancock
601 Congress, Boston MA
This building is fascinating on several counts. It was the first example of this type of double skin construction in the US, the entire envelope is a double skin as opposed to one elevation of the building, and it is simply a very beautiful object in person.
The facade system fabricated by Permasteelisa is an 8" "active" facade. The exterior light is a
1" insulated glazing unit. The interior is a single 3/16" unit. Conditioned air is drawn from the occupied space through a filtered slot in the base of the wall at each floor, travels up between the glass units and drawn out through a slot to the return air plenum. During periods of high heat gain, operable blinds which occupy the space between the 2 glass units arrest solar radiation before it reaches the occupied space. The heat is carried out through the flow created by the plenum draw.
A six storey atrium takes up the majority of the south face of the building. The exterior glazing of the atrium is an insulated unit and the walls of the office space facing the atrium are the single glazed units, as if the typical wall had peeled apart to form the occupiable space.
Where this project really sings, however, is in the way the designers took the opportunity to use two types of textured rolled glass on the interior single light of the double skin.
In the spandrel from ceiling to floor line is a glass with a mirrored silver backing, and in the zone from floor to chair rail height is the same
glass without the silver. The result is a facade on the exterior that changes dramatically with the light conditions, and a
beautifully lit interior space.