Images show design changes to base, spire of 1 WTC

New renderings of 1 World Trade Center show recent design changes to the base and spire of the building, formerly known as the Freedom Tower.

The Port Authority of New York and New Jersey owns the World Trade Center site and released the images Tuesday.

Previously the spire was to have been sheathed in a protective covering, but the new images show a spire exposed directly to the elements. Plans still call for the spire to rise to a symbolic 1,776 feet when construction is finished.

The building, slated for completion in 2014, is expected to become the tallest building in the Western Hemisphere, if the spire is included in the calculation of the tower's height. Some critics have warned that the changes to the spire design could affect its status, but Port Authority officials have dismissed such concerns.

The latest images also display a new design for the first 20 stories, which is now expected to be broader than originally planned. Early drafts called for the building's bottom stories to be angled outward.

Flat, stainless steel panels also are new design elements for the outside of the structure on the bottom floors. The horizontal strips of metal are visible in one rendering that displays a tree-lined plaza.