Warren's seven touchdowns were third-most in the nation last year.
"He is as driven and as committed as a young player I've ever been around."
Smith was previously committed to Manny Diaz and Duke.
Allar was one of 36 total and four Big Ten quarterbacks recognized.
The house will be demolished to make room for a replacement for the Pugh Street Parking Garage.
American will travel to Penn State on Friday, February 21, just before Penn State heads to Big Ten Championships.