Seattle Spheres: Unique Construction Problem Solved

by Mike Crook, LEED AP

Unique construction projects can challenge a team to think beyond what’s possible to make it all work.  Seattle Spheres is one of those iconic projects.  First of its kind in Seattle, the three dome-like structures made of steel and glass will house five levels of flexible office space, a large atrium, and street-level retail.  The project has required thoughtful design and well-timed installations to mitigate unconventional project constraints.

One project challenge that played a significant role in the Spheres design was acoustics.  The owner’s vision for this space evokes a peaceful and serene environment.  The sound of mechanical fans churning could potentially affect the acoustical quality of this distinctive space.  The solution involved fabricating custom sound trap ductwork and installing the duct on top of the core inside the Spheres. This specialized duct connects directly to the supply and return sides of the air handler, and it dampens any noise that could potentially resonate through the duct from the air handler.

Due to limited access and spatial restraints in the mechanical penthouse, as well as the timing of the exterior steel construction, our team decided to construct a frame around the custom sound traps so that they could be picked and placed quickly and easily.  Precise planning and field coordination were critical.  The UMC field crew was able to condense 11 separate sound trap pieces to pick and install, to three (3).  This reduced the number of potential safety issues, reduced the need for additional crane time and increased the efficiency of the installation.  It was a collaborative effort by the entire UMC team, from the detailers who drew up the units and supports, to the fabricators who built it all, and the field team who installed it.