Single post arbor designs
It's just four posts and some boards, but a pergola must stand plumb, level and square through all kinds of weather.I chose attractive, naturally rot-resistant western red cedar for this job.
For this project, I built a frame on the ground to mark my four posts' locations before digging.
I moved the frame out of the way, dug the postholes and brought the frame back.
To anchor to a concrete slab or footing, use post anchors like Simpson Strong-Tie's ABA66--these raise the post off the ground, letting moisture escape.
When affixing to the side of the house, fasten the timbers securely to framing and flash the connection.
One thing to watch out for: Tying the pergola to a deck can be dangerous. Finally, local laws require setbacks from a property line to the edge of a structure. As for the dimensions of the building, I never build a pergola that measures less than 80 inches from ground to girder bottom--the same as an interior doorway.