Venting a dryer in a home without an existing opening requires cutting through the wall of the room in which the dryer is to go and the closest convenient exterior wall and running new ductwork to a vent. Without a vent, the humidity from a dryer damages the house.
Choose the place for the dryer, and then plan how the ductwork will run. Plan a maximum of 25 feet for the ductwork, substracting 5 feet every time the ductwork must make a right angle and 2 1/2 feet for every 45-degree turn. Then drill the pilot hole for the vent from the interior of the house, using a masonry bit if the siding is stone or brick.
Use a drill and a 4 1/4 inch hole saw to cut the hole through the exterior wall. Move the pilot bit for this hole 1/2 inch or so away from the exploratory hole so the bit catches. Hold the drill with both hands to maintain control. In case of masonry or stone, draw a circle showing the outline of the duct pipe. Drill holes around the circle with a 1/4-inch masonry bit, and chisel the hole out.
Insert the duct pipe with an attached vent cap through this hole from the outside, anchoring the cap to the wall with screws or construction adhesive, if the wall is stone or masonry. Leave the cap opening facing down, and use caulk to seal between the hole's edges and the pipe.
Attach fittings on the end of the vent pipe as needed to change directions. Keep adding pipe lengths and fittings until it lines up with the outlet on the rear of the dryer. Use a metal pipe clamp to fasten the duct line to the dryer. Use foil tape to anchor each joint along the line. Test the work by turning on the dryer and checking for air coming through the vent. Make any necessary repairs to the interior wall around the ductwork's entry to the laundry room.