You will need to install a firedoor - SABS 0400 TT9.2 states that any door between a garage and a habitable room shall be a solid timber door not less than 40mm thick and with a fire resistance of 1 hour.  You will also need to make sure that a firewall has been built between the garage and the house.  This is a 220mm wide wall to the roof/underslide of concrete slab.