The next project is a pergola and a wooden deck, which looks roughly like the picture above.
The lighter yellow is a walkway and the slightly darker yellow is the deck itself. The deck area is approximately 6 x 6 meters.
The blue "blobs" are where I plan to place the posts for the pergola, and then the pink lines indicate how the wooden structure will look. Closest to the house, I will leave free from longitudinal beams as there are a few steps up to the door.
I will have a sun sail that can be rolled out on top, and I think it would be nice to be able to hang basket chairs from the framework. I also saw a neighbor in the area hang their children's swings in their carport, which might be good to do in the future
In the corners away from the house, I will place a brace to stabilize the construction laterally. I'm considering whether it is appropriate to attach to the roof trusses towards the house.
I've been looking at 90x270 glued laminated timber for the outer frame and then glued laminated timber 54x270 for the inner crossbeams. What does the expertise say?
If south is straight downwards on the drawing, I would consider rotating the pergola beams a quarter turn. The glulam dimensions you specify only deflect a few millimeters in the middle under their own weight. You should probably specify the "worst case" scenario first as a basis for calculation. After that, it is as much an aesthetic question as a structural strength question.
By "worst case," I mean the greatest conceivable load. Only you can define it. Dead weight and sun sails don't mean anything. Hanging a swing for an adult in the middle might play a certain role. If pergolas are oriented towards the southern sun, the lower evening sun can pass through. But it's not always possible.