The whole window will have a one foot wide window sill. I will have to show you the place to get a good idea of things. Basil planted in teacups for the kitchen, cheap and pretty teacups planted with fresh herbs on the window sill.
Chicken Coop Disinfectant Recipe - orange peels steeped in vinegar for a month, then put in a spray bottle. Making your own instead of buying will be much less expensive. It's sprayed inside the coop when cleaning it to discourage mites, fleas, bugs, etc.