> I know with electricity whether you do it per code or not a licensed electrician has to sign off before you can sell your house. at least i think that's how it is..

Where? No electrician is inspecting every house that goes up for sale in the US. Sure you can ask an electrician to inspect a house electrical… but that doesn’t bar a house sale anywhere I’ve ever seen.

AFAIK the biggest risk is disclosure. Some states (Oregon for sure) explicitly require the seller to disclose unpermitted work. It's part of the standard forms you fill out with your realtor when making the listing.

They won't stop you from selling the house as-is but some buyers will walk, some will demand you get it permitted, most will at least want a real inspection done. Getting as-built work permitted after the fact will cost 2-3x as much in permit costs than it would have if done properly, and it may require you to remove drywall to expose things for inspection, but as long as it meets code you won't have to rip everything out and have it redone by a licensed person. In most places you can do work on your own house, so it's the lack of permit that needs to be remedied.

Barring very obvious problems, I think you're way overestimating how deeply either home inspectors or town/cities are going to be deeply inspecting (especially older) properties and/or permits. My property is over 200 years old and a lot of the work on it has been licensed but there is doubtless a lot that is older.

In the SF Bay Area, I'd bet good money that the vast majority of work like that is unpermitted. When I was adding an EV charging station to my home, I actually paid a (reputable, licensed) electrician and he rolled his eyes hard at me when I asked about permits. He said it would add weeks to the project and double the cost. Without it, it was a three-hour job.

The city isn't in the business of busting doors and issuing citations if you replace kitchen cabinets without a permit. They basically act if someone credibly complains, which is mostly if you're doing some exterior additions / changes that annoy a neighbor.

I mean...what are the odds of that? And if it does happen, it sounds like a hassle, but the overall cost in that scenario probably isn't THAT much higher than having the licensed person do it in the first place?

Sure, if the odds are 50/50, or you go to jail, or the fines are $50k or something, then yeah, do it right from the start.

But if there's a 2% chance of getting caught, getting caught costs you 150%, and not getting caught costs you 10%...the choice is pretty obvious here, isn't it?

It is, but you'd be surprised at the number of folks who will DIY stuff, but won't DIY anything electrical.