This comes up every time people talk about Haml. It's a red herring. You're crazy if you ask your designer to work in Haml. There are few enough excellent designers to begin with; consider yourself lucky to get semantic markup out of them, let alone Haml and Sass.<p>On every professional project I've worked with, we were given markup and assets from designers, and then expected to integrate them ourselves. If you're lucky enough to have a designer on staff, train them in Sass. Otherwise, the process of converting HTML to Haml and CSS to Sass isn't any harder than converting mockup HTML to templates.<p>On the opposite side, if you just need a refresh or a facelift, you give them the HTML and CSS that Haml and Sass generate. It's nicer looking than ad hoc markup already.