Cowell, 53, has spent the huge ransom to turn his home into a fortress, reported Sun online.
"Simon's a perfectionist about everything and his security renovations were so extensive that he's had to put in for planning permission to get them done.
"He basically wants to transform his London home into a fortress," a source said.
After hearing a loud bang when the intruder crashed through the window when he was watching television in his home, Simon alerted his staff, who in turn called the cops and sent a squad of armed officers to the property.
