A recent change to our Enterprise agreement allows us to install Office at home "for a nominal fee", presumably to defray costs at my place of work. I use open source products for the little bit of (personal) work I do at home, and I've made it quite clear that if the company wants me to work at home, they can pay me to do so, and that includes the computer and any software it may involve. They don't use my car, they aren't using my computer or my software.