I think a high level abstraction with semantic meaning is important. If you want to include the layout styles in that abstraction, that's one thing. But if you

I think a high level abstraction with semantic meaning is important. If you want to include the layout styles in that abstraction, that's one thing. But if you want a simplified way to set the layout without building the grid system yourself, what choice do you have besides including layout-only classes on your html elements? So I agree with Breefield that it's not optimal to have separate class definitions outside of your high level semantic abstraction for the sole purpose of layout. But I don't know of any other way to do it other than just building the grid into your abstraction, which means you can't reuse existing css layout systems (unless you just copy the code... ick...).