Here is a synopsis of what I have done in my stucco'ed house: You will need to frame the opening for a window of course - header, etc. Do this from the inside. After the opening is framed drill a hole in each corner out through the stucco. Draw lines on the stucco from hole to hole. Use a 4.5" cutoff tool or similar to cut out the window opening. Next demo the stucco about 12-18" back from the window area, leaving the wire mesh - this so you can house-wrap and weather seal the new window opening properly. Install the new window. Patch up the stucco in the 12-18" area you cut back using the wire mesh you left during demo. Fix up the drywall and do whatever else is needed on the inside for a window sill, etc.
Have you any framing experience or is this the first? Generally, both the front and back walls are load bearing. One or 2 story? A picture of the wall would help.
From inside as mentioned, find a stud close to where the window will be. This will be one king stud that you'll nail your jack to. I'd do 2 jacks with a 6ft. window opening.
If there is another window on that wall, you kinda want to keep this new one the same height for cosmetic reasons. The new window should have the rough opening dimensions. Its better to go bigger on those then smaller if you get off.
The header, sill, and jacks need to be level and plumb or you'll have trouble with the window install.
I moved and re-sized four windows in my stucco house this weekend. I can echo what has already been said here. There are tables online to help you size the appropriate header for the window width depending on the window placement, i.e. gabled end, first floor, etc.
Frame the inside first. If you're installing a large window, say wider than 48 inches (that's my gut feel, I'm not sure what the minimum really is), into a load bearing wall you'll want to install a temporary wall to support the load while you remove the existing framing. A temporary wall is a "real" wall, fully framed and nailed with studs 16" o.c. about two feet inside of the exterior wall.
Once the framing is in place I used an angle grinder with a diamond blade to cut out the opening.
The windows I replaced were not flashed, and you may be able to tell from my pictures I really have nothing to flash to/against because the stucco is the only layer of building material. I consulted for a while with Home Depot about the flashing issue, and they've assured me the lifetime warranty on my windows will cover me over any leaks for any reason, as well as the repairs to the inside of the house. I took several quotes from several local window companies from names you know; Pella, Anderson, Marvin, and in the end I was sold on HD, and they weren't the cheapest. However they were the only company to offer a lifetime warranty on the windows for any problem. I was skeptical at first but they've really been awesome to work with.
A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. Come join the discussion about tools, projects, builds, styles, scales, reviews, accessories, classifieds, and more! Helping You to Do It Yourself!