More to explore:
Green Roofed Chicken Coop! Building plans for an herb garden chicken coop.
chicken coup with rooftop garden. instead of a chicken coop you could make a dog house with a garden roof
Herb Garden Coop Plans (4 chickens) from My Pet Chicken -- Clever. could be fitted as a doghouse instead of a chicken coop.
Herb Garden Chicken Coop (plans from mypetchicken)