Stalled renovations on a historic University of Illinois building are back on track.

The Natural History Building located on the Urbana-Champaign campus was built in 1892. Later structural problems led university officials to close almost half of the building in 2010 and move offices, labs and classrooms.

The building was already scheduled for an overhaul when officials fast-tracked a $70 million renovation. Then it was put on hold as the university came under scrutiny for potential conflicts of interest with the building architect.

The university has since changed architects. The estimated completion date is now in 2016.

Geology professor Steve Marshak says it's been frustrating, but he's excited about the improvements.

The building was added to the National Register of Historic Places.