ᐅ Construction of a 5.50 x 5.50 meter carport

For a metal roof, consider the acoustics during rain. It might be disturbing. For the structural engineering, I would consult a structural engineer, as this is not entirely straightforward...

For a carport of this size, I would either choose a reliable material or hire a structural engineer. After all, it is attached to the house, and the damage could be significant.