Build a doghouse by constructing a base, four walls and a roof frame, then attaching shingling to the roof and if desired, customizing the house. Choose wood sizes and cuts for the doghouse based on the size of the dog, using materials that do not contain toxic chemical treatments.
Build a square base for the doghouse using four two-by-fours cut to a length that creates enough room for the dog to move around freely. Nail the boards together at the corners, then cut 1/2-inch plywood to size and attach it to the base with nails. Cut two-by-fours into studs, including a center stud for support, to create the wall frames. Nail the studs together, then nail 1/2-inch plywood to the wall frames. Measure and cut out a door that is large enough for the dog to enter and exit freely, then nail the walls to the base.
Build the roof by cutting two-by-fours to the desired pitch of the roof, and nail them to the center of the front and back wall frames, then add another two-by-four to connect the two roof frame boards. Cut six rafters that have been mitred to the angle needed to fit to the center roof frame, and cut notches in each piece where it attaches to the wall frame. Attach three rafters to each side of the roof, then use additional plywood and two-by-fours cut to fit into any open spaces. If desired, add shingles to the roof of the doghouse, and customize it by painting or adding carpeting or a nameplate.