The proposed library complex at Southern Methodist University has grown to 207,000 square feet, about the size of a Wal-Mart Super Center, The Dallas Morning News reported Tuesday.
Looking for design tips, engineers and architects for the younger Bush's library last week toured the George Bush Presidential Library and Museum at Texas A&M University at College Station.
Architects and officials from the National Archives have been meeting regularly in preparation for the first major review of the younger Bush's library, museum and policy think tank's preliminary plans.
"It's like a cake being baked in the oven. It's still changing," said Mark Langdale, president of the George W. Bush Foundation, which aims to raise $300 million for construction and endowment of the complex.
Bush has referred to the center as a freedom institute that will focus on the promotion of education reforms and democracy abroad.