You need a 42" hood. You need that additional capture space over the burners as cooking byproducts don't go straight up. They spread out as they rise, so you need something wider than the production zone in order to capture them. Or else you'll get some bypass, and grease deposits on the wall and adjacent cabinets.

600 CFM should be adequate for the range and your cooking style. If you do do high heat searing, it may not quite be adequate for that task, but with only a 16K burner, you're not going to be able to do a large amount of that for long before the temps in the pan drop down too low to actually sear. And you can always open a window a bit when you do that type of cooking in small batches for an extended period.

As to whether or not the cabinets should abut the hood, it's always best to let a focal point like that have some breathing room. As pictured, the proportions are much too small and squinched into place. It would look much the same with a 36" over a 36" with stuff crammed right against it. You chose a chimney hood to make a statement, so let it make that statement. Or if you really can't spare the extra blank space, go with an under cabinet hood instead. That will look just fine with the run of cabinets going straight across the top. You'd still need a 42" hood though, or your light rail would be in the fire zone and it would be a fail from the inspector.

Thanks hollysprings!

Here is an updated version of the kitchen with bigger appliances. The range is 36" and I think the hood is actually 42" (it looks bigger to me). Currently the upper cabinets are 33" wide and touching the hood - if I make those 30" will that give me some good "breathing room" and help it pass inspection with the light rail? Or should I go even smaller?

A follow-up question about the burner output. My husband does some searing. How do I know if those low BTUs will be enough? We currently have an old electric GE coil range and it seems to work just fine. I don't know how to compare the electric vs gas.

Thanks again!

Make the wall cabinets 3" smaller and it should be fine. As to BTU, you can still get a sear on steaks, but you will probably need to do them one at a time using something like a cast iron pan that has a lot of thermal mass to keep the heat drop from being so precipitous.

As to what is "enough", it depends. Many people find themselves cooking more in their new kitchens. It's always easier to turn a burner down than to wish you had more power that isn't there. You should take a trip to a local appliance showroom that has a few ranges set up to be able to test drive. See what you think you need, based on what you cook now. Then, go one step up in power if you can afford it. The BTU power game costs money to play. So, if you rarely do stir frys or sear a steak on top of the stove, you can probably adapt to doing it in smaller batches. If either of those things is a frequent activity, you should really put some testers through their paces before making a decision.

But, also remember that more BTU's means more CFM's needed for venting. And that can trigger makeup air needs. A lot of people do a lot of their high heat cooking on an exterior grill because it's easier to get the results that they want without having to deal with the smoke and grease in their kitchens. If you go "good enough" for inside the house, you might want a good grill for the patio next to the kitchen so you can have the best of both worlds accessible to you.

Abutting the side cabinets will help direct rising and spreading cooking effluent into the hood. However, with a 42-inch hood, you would have decent capture anyway, so if aesthetics dominates your aesthetics-performance-cost trade space then leave a gap.

kas

In your case extra width is not as important as normal, on your selected range the main 16k burner is center middle, I would imagine that will be where you will most if not all your high heat cooking which generally produces more smoke and grease.

Extra depth is always more important on ranges with 6 burners or 5 burners with the main one in the center..... PROVIDED you cook smokey greasy foods on the center burners.

I agree with Trevor that I'd be more concerned about depth than extra width. A lot of hoods fall short in this regard. Don't look at just the overall dimensions but also at the actual intake area.

I also agree with Hollysprings that space between the hood and the cabinets is aesthetically desirable for a chimney style hood. If you want to go 42 and 42 is the most space you can afford I'd look beyond chimney style. If your heart is set on chimney style and don't have more than 42 to play with I'd personally go for 36.

Wow, thank you everyone for your input. I had a busy day and haven't had time to think over this information, but I really appreciate the help.