When the city reconstructed our street there was lots of short pieces of new plastic sewage pipe laying around. At the end of their shift I collected these pieces. The contractors would bury the pipe pieces the next day, I hate to see anything go to waste.

The inside pipe diameter is 4" the pockets for side rails ½ by ½ and the end pieces were scrap pieces of ¾ plywood sheeting, at any house building project there is lots of this plywood as scrap, I made a file for my CNC and cut about 40 of these front and back pieces.

I cut the pipe on a angle about every 10 inches, rotating the pipe every cut 180 degrees so the only waste were the first and last cuts.

The side rails to hold the front and back are red cedar and glued in place being sure to have the plywood about a ½" inside the shortest end of the pipe, this will keep the rain from entering the house.

Slide the pieces into the pipe and hold in place with a brass wood screw through a hole drilled in the bottom of the pipe. I use only one screw into the front or back plywood, that is all that is necessary.

The entrance for the bird is 7/8 to 1" for House Wrens, the overhang privents large birds like starlings robbing the Wrens nest, sometimes I place a ½ " perch and somtimes I dont. I drill a hole in the top of the pipe at each end and hang the house on a branch.

I have lots of these little houses hanging in trees around our farm and even back in the bush. Sometimes in the spring I take the odd one down to see if it had been occupied the previous year and am happy to say there is 90% occupancy. I usually don't clean out last years nest, the female will do this, throw the bits of the nest on the ground then use the same materials to rebuild. Wrens eat insects they catch on the fly and will eat 1000"s of mosquitoes each day.