The common below-grade structural system for the buildings at Harvard & Highland consists of cast-in-place concrete parking structures, utilizing high strength steel reinforcing in the slabs, columns, beams and walls.  The above-grade residential floor system consists of 7.5-inch slabs of steel-reinforced post-tensioned concrete.  Taken together, this high quality, high strength structural system provides three very important benefits to future owners:

• superior fire resistance—since all materials are incombustible
• superior seismic resistance
• excellent sound attenuation properties

The 6.8 magnitude Nisqually Earthquake in Western Washington in 2001 serves to remind everyone of the potential for seismic activity in this area.  The earthquake resisting system for all the Harvard & Highland buildings consists of Horizontal Concrete Floor Diaphragms transferring loads to Vertical Reinforced Concrete Shear Walls.  In the lower parking levels, these concrete horizontal diaphragms (slabs) also transfer seismic loads to the continuous concrete walls below grade, which offer even greater stiffness and resistance to seismic loadings.