First Floor Balcony

[Triassic]

The last job in my self build is a first floor balcony. The Structural Engineer sized it for timber beams. However I’m wondering if a galvanised steel sub-frame would be a better, more durable solution? Has any experience of using this type of system?
 

 

Here is an example https://www.deckbrokers.co.uk/sub-frames/

 

[JohnMo]

Easy - go back to structural engineer and ask.