The Wall Mounted Double Premium Pergola by Rutland County in Light Green will transform your patio into a designer outdoor living area. It comes from the new flagship range from Rutland County and what a beautiful piece it is. Sturdy, dependable, an extension in everything but name. The double rafters slot in to form a halved joint (yeah, there, said it), thus improving the stability and strength of the pergola. If this pergola was an actor it'd be Dwayne 'The Rock' Johnson. Not the animated one from Moana, the mean one from Baywatch (I've never seen it)
 
Here is the link to the assembly instructions