Dome Restoration

  • 12,800 inches of cracked cast iron repaired (8,000 inches repaired with the "lock and stitch" and "Dutchman" techniques)
  • 1,215 gallons of paint used to repaint the Dome - 3 layers x 405 gallons each. Final top coat color is "Dome White."

Rendering of the Dome Restoration Project

  • 1.1 million lbs. weight of scaffold
  • 75,000+ pieces of equipment
  • 52 miles of scaffold pipe
  • 2 miles of decking, enough to build a sidewalk 5 feet wide x 2 miles long from the US Capitol to the Lincoln Memorial

  • 5 layers of safety netting in Rotunda
  • 14,700 square feet total Rotunda safety netting, approximately the size of seven "singles" tennis courts
  • 6,100 lbs. total weight of Rotunda netting

Dome Features


  • 8,909,200 pounds weight of Dome = approximately 4,500 tons = about the same weight of 20 Statues of Liberty 

Exterior Height

  • 376 feet height above Potomac River (includes Hill elevation)
  • 288 feet height above East Front Plaza including Statue of Freedom, is the tallest cast iron dome in world approximate height 29 story building
  • 210 feet height above East Front Plaza to the balcony used for Dome tours at Tholos
  • 199 feet height of Dome measured from Dome Skirt to Base of Freedom
  • 555 feet height of the Washington Monument is 267 feet taller than the U.S. Capitol. Because the base of the Washington Monument is 30 feet above sea level, and that of the Capitol is 88 feet above sea level, the top of the Washington Monument is 209 feet higher than the top of the Capitol Building.

a technical drawing of the Capitol Dome and its interior


  • 135 feet measured from exterior
  • 96 feet measured from interior 


  • 180 feet from Rotunda floor to top of the Apotheosis; the Statue of Liberty without her base would fit with room to spare (she is 151 ft)
  • 85 feet from Rotunda floor to first visitor gallery
  • 149 feet from the Rotunda floor to the second visitor gallery
  • 20 feet from the bottom edge of the Apotheosis to the apex at the center of the hemisphere  


  • 108 in Dome
    • 36 windows in Cupola

    • 36 windows in second story
    • 36 windows in Peristyle
  • 12 windows in Tholos


  • 36 hollow cast-iron columns in peristyle set 10 degrees apart around 360-degree circle
  • 12 columns in Tholos
  • 14 over lapping cast-iron plates make up one section of the Cupola
  • 3/8" to 1/2" range of thickness of cast iron in Dome
  • 5/8" thickness of cast-iron in the Dome Skirt


  • 288 balusters in Boiler Plate Balustrade
  • 80 lbs. approximate weight of decorative acorns
  • 72 total decorative acorns

An image that shows the size comparison between an up-facing acorn and a basketball

  • 36 up-facing acorns
  • 36 down-facing acorns
  • 36 grape clusters
  • 4 300 watt "in-session" light bulbs Tholos

Statue of Freedom


  • 15,000 pounds = approximate weight of 4 cars

A detailed diagram of the Statue of Freedom


  • 38 feet tall Statue of Freedom with base = approximately as high 4 story building
  • 19.5 feet statue height without pedestal
  • 18.5 feet height of pedestal


  • 12 wreaths are on the base of the Statue of Freedom
  • 12 fasces, symbols of legislative authority, are above the wreaths


  • 10 lightning rod points sit atop Freedom’s Roman inspired headdress with native American influences

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