Jeffrey Galm, an assistant fire chief with Milan, said about 45 firefighters were on the scene.
According to officials, crews were hampered by materials inside the home. Flames were already breaking through the roof over a garage that was converted to a living space.
The blaze broke out about 7:20 p.m. Saturday on the 600 block of Crouse Street, south of East Exchange Street, an Akron fire department news release states.
The man's wife was unaccounted for, but was eventually found safe, according to a spokesperson with the Gwinnett County Fire Department, who added that the woman was away visiting her daughter. Two people are displaced and being assisted by the Red Cross. There were no other injuries reported.
Crews remained on the scene for several hours to ensure the fire was out. Neighbors called 911 to report the fire around 11:20 am after they heard a sound that resembled an explosion. The cause of death was ruled as smoke inhalation.