My favorite headcanon i have picked up from elsewhere is that shane knows how to fix things in his house. If the sink isn't draining, he can absolutely get under there and fix it. He doesn't always have the time, so he does still call people for things, but he does have the skill to do all of these things. And lowkey its very good for his mental health to have a small problem he can fix and see immediate results for. He has never felt more free and uninhibited than just after he snakes his shower drain and the water runs smooth again.
I was personally the kid that was following my dad around everywhere when he tried to fix stuff, put together furniture, hang a paining, etc. I loved using the stud finder, the little level thing, paint rollers, etc. Like grown up arts and crafts meets legos. Clear instructions, challenging but not impossible, feeling fulfilled when its done.
Thats all right up shanes alley. Plus with all his question? Kid shane was like "Okay dad, why does the pipe have a bend? Is the water stuck cuz the bendy pipe? Whats stuck in there? Can we get it out? How do we get it out? Can I hold the bucket? Can i do the wrench?" He was not a super verbal kid, except when his dad was fixing things around the house and then he was CHATTY. And Yuna and david absolutely encouraged it because it helped him practice being social, asking for what he needed, he was always much calmer after and would nap really well.
And i think he really got into architecture because of that too. Its his own personal puzzle. he gets to know how everything works. he was asking the builders 800 questions every time he got to come to the worksite. He was chatting tools with them. "Is this something they sell commercially? Like could I have one in my garage? What brand is that?" and he was also talking material "Okay so why is this better than wood? Wouldn't it be more cost effective? oh its a fire hazard? Whats the likelihood of a fire happening? So if the electrical runs here, does that mean i cant renovate this wall if I want to change something later?"
He also ordered the whole team lunch while they were there.
And so i just think that when Shane and Ilya are living together, and the garbage disposal gets broken (because Ilya is incredibly ambitious with what he puts down that thing), shane whips off to the hardware store and comes back with a new disposal and just installs it that afternoon. And ilya freaks him about it bellboy style obviously.
And then they have a very serious chat about what can and can't go into the garbage disposal.