Simon Cowell, Burglar Scare: 'X Factor' Star Spends Staggering Sum Turning Home Into 'Fortress'

Simon Cowell is shelling out some serious cash -- but it's not for cars, clothes or getaways.

After an intruder snuck into the "X-Factor" judge's house last spring, he spent £100,000 making his London house more secure.

"Simon's a perfectionist about everything and his security renovations were so extensive he's had to put in for planning permission to get them done," a source revealed to The Sun newspaper. ''He basically wants to transform his London home into a fortress.''

While Simon's emotions can be pretty guarded, his house, apparently, was not last March when Leanne Zaloumis, 29, broke into his abode.

After reportedly finding the woman in his bathroom, holding a brick, Simon's security staff managed to detain her in a bedrooom until authorities arrived.

Zaloumis was convicted of aggravated burglary and was ordered to stay away from Cowell, but the television producer is playing it safe by beefing up security.

"He was shaken up," Max Clifford, Siomon's spokesperson said. "Strange as it might seem he feels lucky, because it could have been a gun or a knife in her hand."