Plot Out the Project
Before building a pergola, it’s smart to plot everything out on paper first. If you’re building it on the ground, you’ll need to mark and dig holes for the corner posts at least 3 feet deep (even more if you live in a deep frost area). For extra support, you may want to frame and pour concrete footings for the posts to sit on. Make sure the posts are level and placed at correct intervals before filling the holes with quick-setting concrete.