Any reason why you're just having 3m bifold doors on a wall that's 6m long? Which direction do those glass doors face?Not at home at the mo to access my plans, but the plan is a 6m x 6m room with 3m bifold patio doors into the garden. No side windows.
And what does this room join onto at the other end - just a door to a hall or something?
Depending on your budget, you may want to see which sizes are standard, as bespoke will cost more.Virtually everyone has said to definitely get 2x roof lights 3mx1m in a flat roof
Another factor is what the room is going to be used for?