The positioning of Steel reinforcement should to be as per the Thermacell Residential Engineering Design Manual.

Usually the steel required for a Thermacell house is one Y12 reinforcing bar on either side of each window and doorway on the external walls. AY12 bar is set in the walls above the windows to create a lintel.

For windows wider than 2 metres, a Y16 bar may be used. For very wide windows or openings, additional engineering may be required at your expense. AY12 bar is usually placed continuously around the top course of external walls, which creates a bond beam.

No reinforcement is required in internal walls where Trusses are used, as they are non-load bearing.

In the case of double garage door openings of approximately 5 metre span we recommend the use of two courses (500mm) of 250mm blocks.

The steel reinforcement required would be two Y16 bars at the bottom of the beam and 2Y16 at the top connected by 6mm ligatures every 250mm. They Y16 bars should exceed the doorway by at lease 500mm on either side.
An engineers certificate for all reinforcement may be required with your plans.