"Eh, I'm happy with 'not a cave,' so."

"Gonna give us separate apartments and a few spare in case anybody else turns up and needs to crash..."

He shrugs. "Food storage options would be good, in case you need to head off at some point. And so it'll be useful to the locals, even if we all leave."

"Yeah, I'll put in nice big pantries and freezers..." Edit edit.

"Are we at all concerned about security?"

"It's a flat featureless plain. Probably anyone causing trouble's going to walk in legitimately."

"What security features would you want, though?"

"Hm. Usually shinobi favor making things hard to find, at least to unauthorized people, but that'd be hard here... And even the usual minor stuff like 'make harder to find on a flyover' won't really apply out here, we'd notice anyone..."

"Going through earth's pretty easy, if someone felt like walking through the walls or floor. Metal's a lot harder, so sticking a layer of that in anything would foil at least some stealth. Force people to use the windows and doors. There might be a similar trouble with plastics, though I don't know that's actually been tested."

"I can do a layer each metal and plastic."

"That'll help."

"Can you do an outer layer in a chakra-conductive material? That way if I can reconstruct Uzushio's defensive seals they'll be easier to apply."

"If you tell me what kind of material that would be..."

"There's a specific metal," which he names, "Though that's considered better for making weapons out of. But the wood from Hashirama trees is traditional in Konoha for seal-work and construction."

"We always used paper from a specific grass species back home... And I think Uzushio used basalt? But wood's probably good for a building."

"Veneer of Hashirama tree, got it."

"I can't think of anything else specific."

"Then I guess we will all live in a house according to my personal take on 2080s vertical cob aesthetics." Design design. "Furniture, appliances, food requests..."

...He maybe has a few food requests. There's a few things he didn't get much of when he was with Orochimaru; apparently some things are inconvenient to import when you're a supervillain in a secret lair. Like tomatoes. 

He can have tomatoes in many forms.

Eventually, Cam has the apartment building designed and it goes up. He presents Karin and Sasuke with keys.

Convenient.

He's going to go shut himself in his bedroom with all the lights off and not talk to anyone at all. For several hours. At least. (And no one's going to punish him for being asocial.)

Karin, on the other hand, is actually social.

Though she does have her priorities.

"So... Library?"

"Sure, you want it electronic or hard copy?"

"It was reportedly pretty big, so let's try electronic."

"Local format or a more compact version?"