Victoria Police said it is understood three men, three women and two teenage girls were eating lunch during the collapse at a house on O’Donohue Road at Anglesea before 2pm today.
It is understood three people were temporarily trapped beneath timber from the balcony and were treated for leg injuries.
All eight people were taken to hospital in a non-life-threatening condition.
State Emergency Services volunteers have cordoned off the area and a building surveyor has been asked to assess the building structure.