Why is my new home only sheathed with rigid material at some locations?
Why not ask the builder about the lack of OSB sheathing in those places?
We have lived for 42 years in Dallas, Texas in a 1970 build tract house which has no serious sheathing anywhere. The studs are sheathed in an insubstantial fiberboard (dark brown in color) with aluminum foil on the outside.
The corners are 45 deg angle braced with 1&quot; x 4&quot; boards let in to the studs. Yet the house seems structurally stable. A custom builder from California told me once that stud construction as practiced in the US is far above the minimum required for structural soundness.
EDIT
Impression from the pictures is absolutely 1st quality construction. Exterior studs 2x6 on 16&quot; centers? Is there to be an exterior access tankless water heater in the metal box in the first picture or is that for the electric service panel?
I would bet the builder would have a good reason for leaving off the OSB in those selected locations. Ask them and tell us what they say.