Fire officials say the flames broke out before 5 p.m., blasting through the 10,000 square foot, $5 million mansion.
Property records show the home is owned by Larry Janesky, the owner of Connecticut Basement Systems.
Despite pouring rain, firefighters struggled to get enough water because there were no water-mains in the area.
A dozen tankers had to transport water from town to the scene.
Family friends tell Fox CT that no one was injured and all pets were saved from the home as well.
No word yet on the official cause.
Photo credit to Twitter user @firefd42.