Build out 3x6 meters

[Claesk]

I am unable to assist with construction advice.

 

[larsbj]

Three posts and at least 45x195 as beams doubled along the front edge and a support beam under the top chord.

If you don't place it on rock, make proper posts with a plate at the bottom, e.g., 600x600 mm, so it stays stable.

 

[Claesk]

So 3 beams out from the house on each pier?
3 meters.

And double joists on the outside? 6 meters.