How to open up a window in my shower room?
I have lived and worked in Northern California. There are obscure (frosted Windows) that are great for what you want to do. They are narrow 14" wide and do not require cutting the studs so no permit was required. The most important part of the job was to make sure there was no electrical in the space. Moving or modifying the electrical usually requires a permit. Many stud finders today have a warning that shows if there is wiring behind the Sheetrock. Since there is a very low possibility of electrical in the wall at a normal bathroom wall I would punch a hole and look. If there are no wires the hardest part of the install is cutting the vinyl siding. A top and bottom plate can be nailed or screwed in in place then a remodel window screwed to the studs. The last tough part is trim on the outside to make the opening look like the rest of the Windows. The inside is easy in comparison. A little mudd and trim it can easily look original from inside. Outside with older Vinyl can be tough to match but will look better in a few years.