Plan the dimensions of your project and check with the utility companies to ensure that there are no gas, water, or electric lines near the chosen site for your pergola. Determine where to sink the six posts--three on each side to support the rafters. The supports must align on each side and be parallel with their twin on the other side. You also need to plan the width, depth, and height of the pergola, adjusting as necessary to fit it into the available space. Don't forget work gloves and safety goggles.
