I would not do without a vent hood on a gas stove, ever; it's one of the consequences of choosing to put a stove in an island. (I have an induction stove in my island, and even there I've chosen to have a hood -- and there are no flames like with a gas stove.) I guess if you don't really use it much, it wouldn't be a big deal, but between the cooking particulates/odours and the likelihood of small amounts of CO released, I would choose a vented hood. That's irrespective of the local codes.

I would always put a vent above any stove no matter the location or type of stove.

https://codes.iccsafe.org/public/document/IRC2015/chapter-24-fuel-gas

If you're planning on replacing a range in an island and not replacing the hood vent, that suggests to me that you never use it. Is that going to change when you remodel? Probably not.

Very few chefs in my circle of friends and family use their hood vent. They probably have to clean more as a result...

Now, what is a laundry stove? Do I need one?

If you don't mind your guests knowing you had fried fish for dinner last night, skip the vent.

Gas stoves give off poisonous particulates that will go in your lungs if you don't remove them.

Have you considered rearranging your layout?

Definitely a rangehood!

It gets nasty when you don't have one -- my mom doesn't have one and even with constant cleaning of the ceiling and walls, there's still gunk on them!

Caveat: If you do not cook (and some people don't, they just want a show Kitchen), then you don't really need a hood. But, for me, the lack of a hood would be a deal-breaker if you were trying to sell it.

[BTW...Until last month, my mom had had gas as long as I remember. Last month she replaced her gas range with an induction range! I finally convinced her it would be better in the long run. She's 82 (almost 83) and is having no problems whatsoever learning to use it! She has a great attitude -- she figures learning how to use it and the new tablet I got her for Christmas are helping her brain cells! She's never been afraid to learn anything new!]

Vent. That said, you can probably use a downdraft hood and meet code. They store at counter level and pop up when you turn them on. They are barely functional at removing fumes and grease, they are pretty expensive given their marginal performance, but heck, you get to keep the openness. In fact it’s almost like not having a hood at all...

Is this your forever home? When we were looking to move, I skipped over all homes with an island cooktop, unless they had a proper size hood. It would have to be the home of my dreams for me to overlook a downdraft. If there was no vent, I wouldn't consider the home. Way too smelly and messy (particularly if gas cooktop, since that leaves a nasty film); and also because it was unlikely the remodel was done to code, I'd wonder what other corners were cut.

eam, LOL. I have a downdraft. I didn't install it, the former owner did. My kitchen and adjacent laundry room will remind me immediately in the morning that we had pot roast with onions and garlic the night before. This house has radiant heat in the ceilings, no whole house fan or air movement. I'd been used to a regular vented hood, a heat pump, and could pressure can tuna in my kitchen without worrying about lingering odors. Not now ;0)

I know, they’re so awful. When you’ve lived with real ventilation, there’s just no going back.