A time-lapse video has been released showing the extent of the restoration work conducted so far on the US Capitol building, one of Washington DC's major landmarks.

The Architect of the Capitol, which is handling the project, said on its website that the structure's reconstruction is a critical step for stopping the current level of deterioration in the Dome's cast iron casing as well as ensuring the protection of the interior of the Dome and Rotunda.

The last significant exterior renovation of the Dome was performed in 1959-60, and due to age and weather is now plagued by more than 1,000 cracks and deficiencies.

Planned work on the exterior is expected to be completed in the winter of 2015, and in the fall of 2016 for the interior.

Video Courtesy: Architect of the Capitol