Determine where the most sensible place for a fire escape is in your home. The fire escape should exit from an upper story window in a room that would otherwise be blocked off by fire.
Inspect your exterior wall to determine where the strongest parts are for attaching a ladder to. If the exterior of your home is concrete or brick, you will need to attach the ladder with a hammer drill and concrete screws.
Drill a few exploratory holes into the exterior of your home if it is a typical stick-framed wooden house. Locate the studs in the wall so that you can screw the ladder verticals directly into them for maximum strength.
Screw two 2x4s vertically onto the side of the building, extending from the upper story escape window down to within two or three feet of the ground. These 2x4s should be about 18 inches apart.
Screw ladder rungs made of 2x4s horizontally onto the verticals, placing them every 16 inches from the upper end down to the bottom of the verticals.
Test the ladder by climbing up and down it several times. If it is uncomfortable or awkward to use, adjust the rungs as necessary.
Drill holes through the ends of the dowels, 2 inches from the ends and of a diameter just slightly larger than the rope you plan to use.
String one of the ropes through each of the holes in the first dowel. Leave several feet sticking out the tops of the holes for tying the ladder off, and tie knots in the ropes just below the dowel to support it.
String the ropes through the holes in the next dowel and pull them through so the second dowel is on the ropes just below the knots under the first dowel.
Tie two more knots in the ropes, about 16 inches below the first two knots.
Pull the second dowel down so that it is resting on the second pair of knots.
Continue this process until you have a ladder of the necessary length.
Secure the ladder by bolting or otherwise solidly securing it on the inside of the window where the exit is planned, in a place where the ladder can be securely stored out of the way.
Test the ladder as part of a fire escape practice, by opening the window, lowering the ladder out the window, and climbing down it.