All got out safely thanks to working smoke detectors, firefighters said.
Police arrived around 1 a.m. to find flames coming through a second-floor front window of the 2½-story Dean Street house.
The blaze then blew through the attic before it was declared under control at 3:30 a.m.
Joining Glen Rock firefighters at the scene were Fair Lawn FAST and colleagues from Hawthorne, Midland Park and Ridgewood, with Paramus providing mutual aid. Ridgewood police and the Glen Rock Volunteer Ambulance Corps also responded.
Click here to follow Daily Voice Northern Highlands and receive free news updates.