Climbing plants, and especially grapevines, are ideal to create green projecting roofs in the form of a canopy or "gallery." Some examples are given here. This type of façade greening originates from southern countries, where the oven-like temperatures emanating from walls are rather harmful to the espaliered vines. They are thus trained away from the walls, providing much needed shade at the same time.
To support the formation of a canopy/awning made of vines, sturdy mountings or wall brackets are required through which wires or wire ropes can be threaded parallel to the wall. The brackets are available from metalworking shops, and you will need to make sure that their loading capacity is adequate for high fruit yields, windy situations, etc..
The yearly new shoots will first grow upwards before falling back under the effect of their own weight to settle on the support wires and intertwine with each other. The images below show some vine-training variations which can be changed and combined.