A pitched roof extension over a doorway creates a sheltered outdoor living area. The new roof could also block excessive sunlight from entering a room. You should possess basic carpentry skills before attempting to learn how to build a pitched roof extension. You may also need to obtain a building permit depending on where you live.

How to Build a Pitched Roof Extension

1. Determine the height and angle of the pitched roof.
2. Mark the horizontal locations on the existing wall for the top and bottom wall plates. The wall plates will connect to rafters and joists.
   1. Use a level and chalk line to create the lines.
3. Cut lumber for the wall plates.
4. With a power drill and wrenches, attach the wall plates with anchor bolts.
5. Cut rafters with angled notches on the upper ends to fit against upper wall plate.
   1. The combination square will be needed to mark angles for cutting.
6. Cut bottom ends of rafters at an angle parallel with the existing wall.
   1. Test the fit of your first board and use it as a template to cut other boards if it fits.
7. Cut joists to fit to bottom wall plate and connect with rafters.
8. Nail rafters to top wall plate.
9. Nail joists to bottom wall plate and connect to rafters at roof edge.
10. Cut and fit plywood for roof decking to nail over rafters.
11. Spread roofing paper over new roof and nail in place.
12. Shingle the new roof, starting at the bottom and working your way up.
13. Attach soffit boards underneath roof overhang.
14. Nail on fascia boards.