How much indoor space are people able/willing to commit to gardening?

We did some research to find out how large our indoor planter should be. Our method was to take cardboard boxes of various sizes to peoples' houses so they could get a feel for what would work as a veggie/herb planter in their home, (as we have decided to focus on food growing at this stage). We involved a range of people living in different environments, eg. students in shared flats and home owners. Overall people wanted something that would fit into a very small space, about the  size of an A4 page max. We'll base the size of our planter off this research. -Tom and Yvette