Hi! In order to maximize my tiny yard space I have decided to build up rather than out... The plan is to have the chicken run under the veggie garden which will be a giant box basically. What is the minimum height for the run over the chickens heads? I see that some people have a raised house with a run underneath, it would be something similar. They will be standard heavy breeds. Also, I plan on having a tiny coop so that the majority or their time is spent outside in the covered run, except night roosting. Should I provide them with a nest box outside in the run, or just let them use the one in the coop? I am only having 4 hens. The run will be about 55 sq/ft.