The fire broke out at around 4am at a home on La Jolla Circle just off Walden Road.
When the Conroe Fire Department arrived, they said heavy flames were shooting through the roof.
Conroe firefighters quickly called for a second alarm as winds fanned the flames on the almost 6,000-sf home and threatened neighbors houses.
According to officials, fire hydrant pressure was low, causing additional problems.
Help soon arrived from Willis, North Montgomery County, Lake Conroe, New Waverly, Splendora, River Plantation and Montgomery Fire Departments.
The fire was brought under control after 5am.
The home, which was appraised last year at $675,000, sustained extensive damage.
The owners of the home were out of town, officials said. No one was injured.