RHC Engineering, Inc. Share: Civil EngineeringConstruction ManagementEarthquakeFire ProtectionStructural EngineeringTransportation Planning RHC Engineering, Inc. Visit Website 720 Third Ave Ste 1607 Seattle, WA 98004 (206) 330-7443 Map What's Nearby? Distance: 5 10 15 20 25 50 mi.