The fire broke out around 3:30 a.m. When fire crews arrived, flames were shooting through the roof of a three-story building at Barton's Landing Place off Cliffdale Road.
Additional crews had to be called in as the blaze engulfed nine of the 12 units in the building -- severely damaging the third floor and attic.
They were able to get the fire under control around 4:30 a.m.
All 29 residents reportedly made it out of the building. No injuries were reported.
The Red Cross has been called in to help the displaced residents.
Investigators said the cause of the fire was accidental and began on a balcony of one of the units.