My sister’s house is a classic “converted cottage” and has a porch that was converted in to an interior living space room years ago. The old exterior door, but not frame, was removed as well as the window. Leaving a large opening similar to a kitchen pass through.
I have installed headers for enlarging a door opening in my own house on interior load bearing. However her wall is the original exterior wall which is holding up the 24”ish on center roof.
I want to open the door frame and window opening to tie that porch room and living room together better. What I want to know is, is there a difference when working with an exterior wall? It is carrying the roof rafters.
Do I need to make a header with something stronger like LVL, do I need double jack studs, or are lally columns needed? Also since it is an exterior wall do I have to build a support wall on both that floor and the basement below?