You are free to use the benches on Sky Deck on the 14th floor of the Terminal.
However, please note that Sky Deck may be closed in case of bad weather. Please refrain from bringing things that can easily be blown away.
Please note that your personal items can be carried away by the wind while using Sky Deck.
You can also use the Grass Square (Centrair Garden) on the south side of the Terminal 1 building.
Get down to the first floor of the Terminal 1 building, exit the building and continue to the right.