Tips for building exterior wooden steps include to create a level surface where the steps end, to measure the length of the stairs from the house to the ground to determine the number of stairs, and to use pre-cut stringers on the ends and on every 2 to 3 feet of stair width. Attach an anchor board that is 2 inches by 4 inches and 3 inches shorter than the width of the stairs to the door or house.
After attaching the anchor board to the structure where the top of the stairs go, use 4-inch wood screws to attach the pre-cut stringers to the ends of the anchor board. Cut 1 1/2 inches off the top of the middle stringers and attach them to the anchor board so they are flush with the top of it. Cut 1 1/2-inch thick and 12-inch wide pieces of wood that are the proper length of the stairs. Use the wood screws to attach the stairs to the stringers.
To determine how many stairs are needed, divide the distance from the ground to the top of the stairs by seven, as most stairs rise by 7 inches. Each step usually has a length of approximately 12 inches, so multiply the number of stairs by this number to calculate the total distance from the back of the stairs to the ground.