Neil Tulley, 54, was discovered in Cedar Way, Guildford, Surrey, just after 10am on Tuesday, and a post-mortem examination found he died from multiple stab wounds.
The 14-year-old, who cannot be named for legal reasons, appeared at North Surrey Magistrates' Court today charged with murder, Surrey Police said.
He has been remanded into the care of social services and is due to appear at Guildford Crown Court on Tuesday.
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Thursday evening's weather for the east of the region
Thursday evening's weather for the west of the region
One of Clandon Park's most historically important rooms has survived the fire that gutted the rest of the 18th century mansion.