The man's body was found over the weekend, after a fire Saturday destroyed the home.
Lake Zurich fire officials and the Lake County Coroner's Office said the body was found Sunday in debris at the destroyed home on Rosewood Drive in Hawthorn Woods.
Lake Zurich fire officials previously said there was a "missing husband" involved in the fire.
Sherman Della, 73, was identified as the man killed in the fire, according to the medical examiner.
Della is believed to be a family member who did not live at the home, the coroner's office said.
The lack of fire hydrants in the area caused some problems for firefighters over the weekend.
Fire investigators say the family had an electronic vehicle and charging station in the garage.
While they are unsure if that is where the fire started, they said it created extra challenges in putting the fire out.
The Hawthorn Woods Police Department, Lake Zurich Fire Department, local fire investigators, and the Office of the Illinois State Fire Marshal are investigating what caused the blaze.