Ouch, it sure seems like reinforcement of a window header, short wall, and the surrounding wall studs would be sufficient... with lots of blocking. You only nee

Ouch, it sure seems like reinforcement of a window header, short wall, and the surrounding wall studs would be sufficient... with lots of blocking. You only need enough strength to prevent buckling or deformation right there. I see lots of houses with multiple windows or sliding doors across the back... they seem to treat the vertically continuous wall segments as independent so it's more like several separate back walls. Taken that way you just need enough cross-bracing and reinforced headers/footers no? At least the city is approving those sorts of designs without massive moment frames covering the entire rear wall. (My house fits this with the rear wall being 60% window or sliding door and no steel, but the walls are 2x8 with a lot of blocking and diagonal cross-bracing; the perpendicular internal shear wall connected to it is also built with 2x8s). Garage doors are as difficult as ground floor parking. They often take up the entire building frontage so you need significant reinforcement. My house has a steel moment frame set back from the door opening half the depth of the garage because it has to support a 1.5 car width span and the primary sheer wall for the second floor directly above. The house pre-renovation had none of that, just toe-nailed pillars like lots of SF garages which would have made that part of the house vulnerable for sure.