Theorists facing tenure track faculty interviews
If you don't need lab equipment or space to do your research then just say so and explain what, if any, support you do need to conduct your research (e.g. travel funds, a desktop computer, a chalkboard, coffee, etc.)  

If there is an expectation that you will bring in external funding to support graduate students, then you need to be prepared to respond to questions about possible sources of funding and how you will involve graduate student research assistants in your research in a way that will be considered appropriate by both the funding agency and your future institution.   Not being prepared to answer this question could very well cost you the position.