Thanks, BTW -- how can you tell there is no seal / buffer between the window frame and the outside render???
I google some pics but can't tell it very clearly.

I see -- the idea is that there should be some buffer between metal frame window and the render~~

Thanks, so you mean this is common for minor movment? -- but I should keep monitoring in case the cracks become bigger?

According to the plan, it is foam!!! haha does it matter with how I fix it? I only know putty~~~or gap filler?

There is a vertical crack in my 3-year-old house -- just outside the windolw frame
Am not sure if it is servious? The room is facing north so it maybe due…