JPMorgan Chase has granted the owner of Chicago’s Old Main Post Office, 601W Companies, a $500 million construction loan, according to the Chicago Tribune. This is one of the biggest real estate loans ever granted to a Chicago project.

A previous report estimated the redevelopment would cost around the $300 million mark, but the Chicago Tribune reports that 601W Companies will likely spend about $800 million on the project. The redevelopment of 2.8 million square feet is one of the biggest projects currently underway in the country. 

The Downtown Gateway District, which includes the Old Main Post Office, was one of the 10 sites included in Illinois and Chicago’s formal bid for Amazon’s HQ2 Campus. 

The redevelopment of the building is slated for completion by March 2019.

“When completed, The Post Office will reset the standard of office communities through its truly unique combination of historical elements and forward-thinking design,” said Brian Whiting, president of the building’s leasing company Telos Group, according to the report.