The basement stays four degrees cooler than code requires, because the colony under the floor joists does better below eighteen. The sunroom runs the other way, ten degrees warmer than the rest of the house, glass angled for a lizard that needs the heat more than the humans need the view. Nobody argues about the thermostat anymore; there are six of them, one per zone, and the house charter pinned by the door lists whose zone is whose.
The eaves have their own entrance, a gapped soffit too narrow for anything but the bats that use it, and the porch light on that side of the house runs on a schedule keyed to their flight times, not to whoever's coming home late. Under the kitchen, a mycorrhizal mat the foundation was designed around rather than simply poured through, tied by root and hypha to the three fruit trees out back — the concrete has a deliberate gap in it, patched with mesh, for exactly this reason. Mason bees have a block of drilled timber bolted to the fence, replaced every few seasons. A compost column runs floor to roof through the utility wing, load-bearing, feeding the trees and taking the kitchen's waste both at once.
The charter is short and gets revised more than it gets read. It says what happens when the resident owl's hunting hours conflict with the housecat's feeding schedule — the cat eats indoors after dusk, no exceptions, and the humans stopped fighting that rule once the second owl arrived. It says where death happens: a decomposition closet off the utility wing, not the trash chute, because dying indoors is scheduled for and returned to the soil, not bagged and put at the curb. It says who gets a vote on the zones and who just gets a voice — the humans, the bats, and the trees get votes, roughly speaking, cast by people who've learned to read what each of them needs; the cat does not, and knows it, and resents it in the ordinary way cats resent things.
None of this reads to the family as an argument. The eleven-year-old's homework this week is a floor plan of the house with every non-human resident labelled, due Thursday, ordinary as a worksheet about the water cycle. Nobody in the house is making a case for cohabitation. It's just how the house works, the way a thermostat used to be one number instead of six, before anyone here remembers it being otherwise.