Missing Window Flashing
In the picture above this sliding glass door was
installed directly over the OSB siding. This was a porch that was
enclosed and is now being used as living space.
This sliding glass door has no wood trim over it and has been installed incorrectly. The siding should have gone over the door flange and not under it.
This sliding glass door has no paper flashing around its flanges and eventually could leak over time.
You will find this often on your home inspection journeys where someone has converted a porch into a bedroom or living room. Most of these rooms will not have building permits for either the outdoor patio cover or the new enclosed room addition.
Most of the time when the workmanship looks bad, there were no permits pulled and this could be a problem if you buy a house. Some room additions or patio enclosures will have to be demolished and rebuilt to meet local building codes.
Some of these homes can be sold with out listing these rooms as living area.
Window Flashing And Lath Paper