At the moment NCrunch doesn't include integration with SVN (or any other VCS). Because it can't control when people check in, there's no way to block it. There are some very speculative plans around VCS integration with NCrunch, though these are still a very long way off and the use cases haven't been fully planned out yet. Thanks for the suggestion though - I think for the time being I would have to recommend looking at alternative tools (I'm sure this is a common problem!).