Keltham's brain does automatically generate the question 'How many dead siblings?' but it doesn't make it to mouth.

"I had an odd childhood for a dath ilani," Keltham says.  "A lot less optimized than most childhoods are.  My parents weren't driven to make my life as perfect as possible, just substantially better than not existing.  I agree with them about that, to be clear, but still, a lot of dath ilani would be - well, actually were - politely horrified about it.  Like, lots of moving between different parts of Default - uh, that's the biggest city in Civilization where you live if you want to live around lots of options, and you don't have any particular reason to live anywhere else.  Other parents would've been worried about frequent moves disrupting my childhood relationships.  On their philosophy, maybe that wasn't literally optimal for me, but I'd probably be basically fine, so they went ahead and moved any time they got bored.  Single-family house-module with only a couple of secret passages, one of which was in the house library and just went around a corner from one bookcase to another bookcase in the same library.  I am currently making an error and my error is that I am not eating."

Keltham resumes eating.

"That doesn't sound very odd for Golarion but usually it'd be because the family had a job that required moving, not because they got frequently bored."

“How do people move around here, when their job requires it?  This villa seems like it’d be very hard to pick up intact and move somewhere else by nonmagical means, and most people can’t afford teleports so that’s not it.  Do you just swap houses and all your stuff with another family of similar size that happens to live in the right place?  Doesn’t seem like that should happen at the same time often enough, unless you have a monthly Moving Day, and Golarion seems too uncoordinated for - shutting up now, eating.”

Everyone looks incredibly confused at him.

"...if you're a priest, there's housing in the temples for priests assigned there and children they're raising," says Meritxell. "And if you're anyone else you look at apartments in the new place and sign a contract with a landlord for an apartment that has features you want and then move your possessions there. In a wagon if you have a lot of possessions."

That really sounds like something that would sound superficially plausible but then turn out to not work quantitatively, once you started running numbers on how many empty houses you needed all over to always have the right subtype of house available for people to randomly move into…

"So even at the cleric or wizard level, houses must not have... expensive, non-modularly-removable features that only a few people want, because you can't take it with you if you leave the house?  Just features that everybody wants, or stuff only you want that you can take with you when you leave?"

"Or features that are common enough there'll be a vacancy that has it," says Meritxell. "It doesn't have to be universal. But if you want something absurdly specific you'll have to rebuild it if you leave."

"Wait, how do houses get to places in the first place if you can't move them once they're built?  Like, this house looks to be way out in the middle of nowhere, if you can't move it, how did it get here after somebody built it?"

"....they built it here."

"So, like... there's a place that makes sections of walls and floors that are small enough to be easy to move, and they ship the sections of walls here, and a local crew assembles those into a house using tools that are also small and easy to ship around...?"

"....you cut stone and lumber and ship them down the river and then have mules drag them to the site, and then at the site you build the stone and lumber into walls, using, uh, stonemasonry tools and saws and so on."

"Mules drag them to the site.  Do you not have wheels."  Keltham quickly tries to recall whether he's seen anything with a wheel built into it.  He hasn't.

"Yes, we do! Mules drag wagons to the site if it's not too steep or rocky for that."

"Is it, like... not particularly more cost effective, the way your economy usually runs, to have one place that makes lots and lots of something; instead of making a single copy of something, wherever it gets used?"

"Definitely not for houses, the transport costs would kill you. It...makes more sense to have one shipyard than a dozen small shipyards?"

"Okay, good.  When I heard that you were assembling single copies of houses, from raw materials, in individual places, without even trying to build pieces of houses in a single place and assemble those pieces, I was wondering if your whole world just didn't have centralized manufacturing for some reason."

Ione has never done anything in her life like what she's about to do, not since she was old enough to remember, and if her soul belonged to Asmodeus she probably still wouldn't have done it.

"Keltham, you're supposed to be eating," she says.

"Right."  More food.

...actually, even if it's relatively safer now, Ione is not entirely sure why she did that.

No one else gives her an odd glance about it because they're too well trained. "Laborers' time isn't very valuable so for most things it's more worthwhile to send the laborers to wherever you want them laboring than to figure out how to send a bunch of pieces of something across the country," Meritxell says. "For shipbuilding it makes sense to do it all in one place because you always want your ships in the one place and you have a harbor right there to send all the materials your laborers will need and also it's quite specialized."

Keltham nods; his not eating error having gotten so bad that even other people have started to notice, he does not reply per se.

"Most people build their own houses," Tonia offers. "Or their neighbors come over and they all raise a new barn together, from trees they felled from the forest right there and shingles they baked in the kiln right there."

Swallow.  "Don't hire specialized housebuilder because?"  +Nom.

"The village has a hundred people in it and there's a specialized priest and blacksmith and tanner but that's it. Someone in the village needs a new barn raised or house built maybe once every couple years, and that's not often enough to be the only thing someone does. And you don't get visitors often enough to tell them 'oh, you should send a team of housebuilders from the city, I'm going to want a house in the spring', and if they did come you couldn't afford them. And people are idle, when it's not planting or harvesting season, so they may as well improve their land."

Keltham bumps up the priority of 'cheaper travel' on his list, for causing people to, like...

...trade with each other instead of doing things they're not specialized in.

"How do nonwizards get between a smalltown and the nearest mediumcity to the smalltown?"

"By boat, if it's on a river, or riding a horse, if it's not and they have a riding horse, or walking, if it's not on a river and they don't have a horse, and poor people don't have riding horses," says Tonia.