Unlike Luz, Vash is definitely NOT the creative type who is good at anything like rebuilding or designing complicated architecture--even if it's for munchkin-sized people.

While he might not be GOOD at this, he's definitely a good help to have around, at least. Willing to do whatever grunt work needs to be done. Having superhuman strength really does stuff in your favor when you're not exactly magically-inclined like most people.

He absolutely notices Luz has been pouring her everything into work since He's arrived--and being empathetic towards humans as he is, he can't help but take a pause to wave at her with a bit of a goofy grin on his face.

"Hey, not that it's any of my business, but... while I'm definitely a guy who can appreciate hard work, I think you're due for a hard break, too.
Have you even eaten since you got here?"