one on the other side of the roof,and under the over hangs run both sides of the building long ways;See how the over hang on the roof extends about 4in that is actually vented and has screen or regular vented material that won't let birds in but is open for air those run both sides of the roof so 6ft on the east and west side then big square vent on the west side of the roof maybe 1ftx1ft qnd the window slides open as well as the big door has a hard wire second door for the summer and of course the 2 trap doors