ridge runner

I've got to install some 2'X5' windows in an existing interior non load bearing wall which has steel studs 16" on center starting with cutting out a new hole. The windows will be custom sized when rough openings are done. I've often worked with wood framing but am new to steel. I'm mainly interested in the method to attach both the sill and headers for the rough opening. I believe I can build out the sides by screwing in 2x4's, etc. to the correct dimension. I'm trying to avoid opening up the walls too much as they are 1/2" drywall covered with a painted,tight weave, burlap covering of some type which I won't be able to effectively match or patch up. Plan to cover perimeter with wood trim to finish. I'm intending to sawzall out a rough opening as tight as possible to start and am considering sistering in 2X4's on the studs, then attaching the sill and header to that. Is there a more appropiate method for this? I'm thinking I'll need some solid support top and bottom for a 5ft. wide window. Any help will be very appreciated.

innovous

Just to CYA you might want to add a steel stud in each of the cavities (if they are clear of electrical, etc.) for the sill plate to mount on. Once drywall is on, steel framing is pretty darn strong. For the header, maybe insert some additional cross-bracing to keep it from racking during install. Sounds like you are on the right track, just make sure all fasteners have solid connections and everything is nice and plumb/level (steel framing can be a pain to re-do). Hope this helps, post how it went for you when you are done