[baddox]

Well then what’s the alternative? Using the same spacer component everywhere is bad because the designer might want to change the spacing in only one spot? Okay. But what if the designer wants to change the spacing in all spots? That’s a much more likely scenario in my experience, but the point is you need to be able to do both.

[aphextron]

The point is that layout should be handled at the highest level possible. Have a CSS file at the application shell component level which defines a baseline margin and grid for components, then have individual page component level CSS that can tweak those layouts where needed. Actual UI components should then only ever need to use padding.