Don’t assume corridors.

This is my mental shorthand for reminding myself that, when you’re looking at history — and when you’re building a secondary world — certain things you take for granted as natural and inevitable may not be. Back when I started drafting the Elizabethan faerie fantasy Midnight Never Come, I had two characters conversing while walking down a corridor and out onto a balcony at Hampton Court Palace. Got to London for my research trip and discovered that not only does the building have no balconies (which I would have known if I’d looked more closely at pictures), but back in that era, it had no corridors. No hallways, passages, or whatever word is used in your locality for the interior spaces that connect rooms to each other. Instead, rooms just opened directly onto one another: an arrangement you may have seen if you’ve visited a stately historical home from the eighteenth century or watched the kind of movie set in such places.

Hallways give you greater privacy, by providing a buffer of empty space between rooms and by making it possible to come and go without tramping through other rooms that may be occupied. But they also kind of waste space, since the hallway is only used for coming and going, maybe with some decoration to liven it up. I’m fairly sure they became more common post-industrialization, when cheaper materials and greater efficiency in construction made it easier to justify empty space like that.

But the idea wasn’t unknown in earlier ages; it just tended to appear somewhere else. Specifically, on the outside of the building, rather than in the middle. Quite a lot of places are fringed with covered colonnades, peristyles, loggias, verandas — again, there are a number of terms. These not only grant shelter as you pass from room to room, but shelter the rooms themselves, preventing the rain and sun from beating directly on the walls, doors, and windows (while still allowing for some natural light). In Japan, these spaces could sometimes be closed off with removable shutters in the winter, thereby providing a modicum of insulation for the rooms behind them . . . and, yes, turning that space into a corridor.

Going back to those stately eighteenth-century European houses, though, some of them did have corridors — just not for general use. If you were rich enough, then not only did you have servants, but you could afford to build in a fashion that minimized how often those servants had to be seen. If you’ve ever spotted a camouflaged door in the wall, paneled or papered to look like everything around it, that’s a servants’ door. It probably gives access to a narrow passage behind that leads to the service areas of the house — often including a dedicated staircase — so that servants could come and go with minimal disturbance to the inhabitants and guests. (In the really ugly scenarios, e.g. those where the servants are actually slaves, there might even be an intent to segregate them so they don’t “sully” the regular doors and stairs.)

This points us toward another broad principle of layout, which is the separation of the public and private. Even in a one-room peasant’s hut, odds are good that the bed will be at the back of that room, and the work area is at the front. That’s partly for practical reasons — you don’t want to be carrying firewood and buckets of water and dead chickens past your bed, or hauling those things any farther than you have to — but the pattern persists throughout many types of residence, even when there are multiple entrances giving direct access to other parts of the building.

Quite simply, we tend to differentiate “that which strangers are allowed to see” from “that which is only for the family.” These lines aren’t hard and fast; people sometimes chose to entertain guests in their bedrooms, with the host even lying in bed during the conversation. But that was usually a mark of intimacy, an honor of sorts offered to select guests: “You may enter my private sanctum!” Less privileged guests were received in public rooms.

Private space comes in two kinds, though, one of which is bedrooms and other personal areas, the other of which is the service quarters I mentioned before. The shift toward open-plan architecture in recent decades is a deliberate, though not complete, breaking of that latter distinction: rather than the kitchen being separated from the dining and other social areas, it’s incorporated into them, in ways that genuinely reflect changes in the status of women and how we entertain guests. The laundry room, however, is still probably separate, or tucked into a closet: that part remains not for public viewing. (Though attached garages in car-centric cultures can make a weird hash of this, if you pick up a guest at the airport, drive them to your house, and then . . . bring them in through the laundry room.) Worth thinking about when worldbuilding, even if household tasks are carried out via magic or handwavy technology — where do you put your matter replicator?

How the spaces get separated will depend on the overall architecture. In a house built around a courtyard, reception areas will be toward the front, service and private chambers toward the back. If you have enough space, the service areas — including quarters for the servants to live in — might even be one or more separate buildings; as the kitchens essay in Year One mentioned, this is important for removing smells and fire risk from the main building.

If instead you have one structure, but it’s multi-story, then many of the personal spaces will be upstairs. Not too far upstairs, though; a place big enough for servants’ quarters often sticks them in the attic, where you have to climb a lot of steps and then probably put up with sloping ceilings encroaching on your space. Or, if soil conditions permit, service rooms and servants’s bedrooms are placed in a half-basement: not fully subterranean (as that creates its own problems), but with only a thin strip at the top where windows can let in light and air.

None of this, to be clear, is a hard and fast rule. The specifics will always depend on circumstances — which include fashion. Once garden design really got rolling, a lot of European houses placed their main entertainment rooms on the “piano nobile,” an Italian term for the first floor above the ground, from which you could have a nice view. Meanwhile, in the days before indoor climate control, it was fairly common for Mediterranean households to preferentially occupy the cooler ground floor in the summer, then move upstairs for the winter.

And shifting like that was made easier because of the last principle to bear in mind: that we are far more committed these days to the notion of dedicated, single-purpose rooms than people used to be. We even have regulations saying things like “bedrooms must have exterior windows for safety” and “you can’t list a rental space as a bedroom if it doesn’t have an attached closet.” But when the function of a room depended largely on what furniture you put in it and people had a lot less furniture, then rearranging according to the needs of the moment was much simpler to achieve.

So the layout was what you made of it. But the underlying principles were common enough to be fairly safe bets to lean on!