Rendering of the 10th  O Street Project from the corner of 11th and O Street
Rendering of the 10th & O Street building from the corner of 11th and O Street


The building will temporarily house approximately 1,250 legislative and executive elected officials and staff from the Capitol Annex until the new Annex project is completed. The building will then be jointly used as office space for legislative and executive employees. The 10-story building will be approximately 472,600 gross square feet and incorporate function space for committee hearings, caucus meetings, general meeting rooms and legislative and Executive Branch offices, with integrated parking.


1021 O Street, Sacramento


  • Sustainability: As one of the most sustainable state office buildings to house elected officials in the country, with the goal of LEED Gold, the building will feature low water use fixtures, a high-performance building facade, materials with high recycled content, day-lighting within office suites, native vegetation on the surrounding site and terraces, as well as LED lighting throughout.
  • Zero Net Carbon: California has established itself as a national leader in the green building movement. Upon completion, the 10th & O Street building will be Zero Net Carbon.
  • Zero Net Energy: The 10th & O Street building will achieve Zero Net Energy through energy efficiency and offsite power generation via a historic agreement with SMUD.
  • Heart: At the center of the building or the “heart”, occupants will find double-height great rooms with open, interconnecting stairs that will serve as zones for social interaction and activation for the users of the building. Adjacent to these great rooms are roof terraces with views of the surrounding city of trees and the State Capitol.

Project Partners:

  • Progressive Design Build Team: Hensel Phelps, partnering with Hellmuth, Obata + Kassabaum (HOK) and Dreyfus + Blackford Architects
  • Architectural Consultant: Hammel, Green and Abrahamson (HGA)
  • CEQA Consultant: Ascent Environmental
  • Construction Management Firm: Gilbane Building Company

Major Project Milestones:

  • July 2018: Project authorized
  • February 2019: CEQA EIR finalized
  • May 2019: Groundbreaking ceremony held
  • Fall 2021: Building to be occupied

Time Lapse Video:

View* the time lapse video of the crane erection at the 10th and O street project site.

*Note: If you do not see the video controls, right click the image above and select "show controls".

Additional information regarding the 10th & O Street Project and the Capitol Annex Project may be found via the State Capitol Annex Project website.


RESD Headquarters Office

Department of General Services
Real Estate Services Division

707 Third Street, 4th Floor
West Sacramento, California 95605

Main Line: (916) 375-4700


Project Management & Development Branch

Department of General Services
Real Estate Service Division

707 Third St., 4th Floor
West Sacramento, California 95605

Phone: (916) 376-1700