It’s 2015 and they still build like this…
Brand new build going up in Phoenix, AZ. What you see is completely 100% framed and ready for stucco. The missing OSB sheathing is done on purpose. They do “open framing” and only use sheathing where required. The rest is open 2×4 framing.
They will stuff R-13 batts within the 2×4 walls, staple on some building paper and then put 1″ of rigid EPS on the outside and use conventional stucco to finish it off.
A recent blower door test on a home like this showed 15 air changes per hour.
ALL of the duct work and air handlers are installed in the 150F unconditioned attic.
The gable wall you see is just a standard truss and it will be left open like that, NO sheathing. Once the home is completed and if you go into the attic and lean on that gable wall. You can damage the wall and move the entire gable wall with just one hand. In high winds the gable wall will actually flex and rack. A truss like that has very little horizontal shear strength.