Idaho State Capitol Wings Expansion

McAlvain managed the design and construction of the Idaho State Capitol Wings Expansion project. Details include the excavation, waterproofing and core and shell construction of two 25,000 sq ft single level below grade buildings including landscaping. These underground wings are additions to the East and West sides of the existing State Capitol building providing additional hearing rooms, conference areas, offices, kitchen and dining room, and storage space. Skylights in the main hallways will utilize natural light.

Capabilities Utilized:

  • Design Build Services
  • Concrete: 8,000 CY
  • Excavation
  • McAlvain self-performed 50% of the work with its own forces


  • Completed under budget and ahead of schedule
  • 2011 Excellence in Concrete Award