Goldfinches usually build their nests in the trunks of dead trees, in the nooks of tree branches or in hidden spots like the eaves of a house. They do this for security and from years of habit. It makes sense that a birdhouse or nesting box designed for goldfinches should resemble a spot the birds would choose naturally. Learn how to build a wood birdhouse: If the nesting house and its opening resemble specific environments, and if it's mounted properly, you have a good chance of goldfinches nesting in your handmade birdhouse.
Cut pieces for the main walls of your birdhouse. Cut seven pieces of the 3/4-inch thick pine to 6 inches x 2 1/4 inches. Cut a 45-degree slope at one end of each piece to accommodate the roof. Cut each piece at a 15-degree angle down each side. This will give the birdhouse a rounded effect once constructed.
Cut the back wall. Cut a piece of 3/4-inch thick pine to 10 inches x 8 1/4 inches to start. Six inches from the bottom of the board, make a mark with your pencil. From that point, cut the sides of the board at a slant, to come to a 45-degree angle at the top. This will accommodate your curved roof.
Glue the seven main walls together, leaving an opening for the back wall of your birdhouse.
Glue in the back wall, which should fit inside the curve made by the main walls.
Once the frame of the birdhouse is glued together, wrap it in masking tape to let the glue set.
Cut the roofing tiles. You will need 15 pieces of 9 1/4-inch x 1 3/8-inch wood, at a thickness of 3/4 inch. Cut the tiles at a 12-degree angle, so the top side is pointed on one end and flat on the other. For the sides of the tiles, cut at a six-degree angle so they will lay flat on a roof.
Fit the tiles onto your birdhouse to make sure they're the right size, and that they lay together. If they fit, glue them on. Use masking tape to keep the pieces together until the glue dries.
Remove the masking tape and sand the roof until smooth.
Drill a 1 1/2-inch hole in one wall of the birdhouse as your entrance. Drill a 1/4-inch hole just below the first hole. Push your bird perch (dowel) into this hole and glue it there. Drill a second 1/4-inch hole in the back of the birdhouse, to use when attaching it to a tree.
Cut the base of the birdhouse using the plywood. Cut the plywood to fit over the opening in the bottom of the birdhouse. Don't glue this on--use nails or screws so you can remove the bottom of the birdhouse to clean it occasionally.
Stain or varnish your birdhouse to protect the wood from the elements. Make sure your stain or varnish is nontoxic.