Most wood hoods aren't designed correctly originally. Don't compound the issue by this bumpout thing. It would be better to rebuild the wall with steel studs and cement board than to do a thousand custom creations here.

You simply put a couple of flat 2x4 blocks behind the hood and it is pushed forward. You cover/wrap that plywood behind the hood in a piece of narrow sheetmetal/stainless steel, which you can buy at HD. It sounds harder than it is. A couple of people on the Forum have done this.

Some people use an island hood for this application. Here is a photo of an island hood bumped out from wall.

Here is Oldbat2be's kitchen. She bumped out her base and upper cabinets, and used a cabinet surround for her hood like you are doing. Her kitchen is exquisite. She surrounded her range with a stainless steel border rather than using her countertop material. I will also link her reveal thread. Be prepared to ooh and ah.

http://ths.gardenweb.com/discussions/2706217/bold-tile-sunlight-filled-kitchen

Thanks, Sophie. We got the 36" hood liner "free" from Jenn Air after purchasing the range top and wall ovens. The next size larger hood liner is 48"-- obviously too big for a 36" range.

My husband is a woodworker and is custom building the cabinets and hood surround. He is going to make the surround 4" wider on each side, which will match the newel posts he made on either side of the bumped-out range top. (I know, I desperately need to figure out how to post pics!). He's going to add a spacer against the back wall to make the liner bump forward enough to match the bumped-forward range top.

Thanks, GreenDesign. We really couldn't reframe the walls, and already have the bumpouts fabricated in our counters. Thankfully my husband is doing everything himself (excepting the counters), so the cost involved in bumping out the cabinets, etc. won't be much!

Thanks, Freida! Those pics of Oldbat2be's kitchen are gorgeous. Her hood design helped us a lot!

The main thing is that you do not want anything combustible above the range. Only metal there. That is the main reason for having a wood hood wider than the range. So the metal liner is the only thing above the range. (And the better capture space for cooking effluent.) You will probably need a custom liner for your application. At that point, it might be easier to do a separate remote blower. It will probably be quieter as well.

Hmm, if the metal liner is 36" does that "count" as metal only being directly above the range? Obviously the wood is combustible, but is there a minimum distance of where that wood can begin for the surround? My husband was planning on building wooden 4" spacers between the edge of the liner and the surround on each side. I know this is not ideal regarding capture, but thought adding that space would help a bit.

A custom 42" hood liner is honestly not in the budget, especially with the "free" 36" liner sitting here. Jenn Air doesn't even make 42" liners, which would seem to be the best size for a 36" range top. I'm thinking the best we can do with the "free" 36" liner we have is what we currently have planned.

Jenn Air does make stainless spacer panels, that effectively add 3" of space to either side of the hood liner. My understanding was that those are just aesthetic, but perhaps I am wrong. Those spacers would not be directly under the burners of the range top, and I thought they were just to help people who want to place a 36" liner in an existing 42" cabinet space.

hmm.. thanks for your thoughts!

Metal is a heck of a lot easier to clean grease off of than wood! Repeatedly cleaning wood with degreasing chemicals will damage it over time. Also, the exact finish on your cabinets will come into play here. I hope your husband owns a HVLP and is spraying a conversion varnish!

The exact hood/liner design will depend on the exact model of liner, and the exact design of the wood hood surround. It's a combination effort. Arches are problems. Light rail is a problem. That all intruedes into the noncombustible zone. It all has to be a minimum of 30" from the cooking surface. Some ranges require 36" of clearance above the cooking surface. No wood of any kind can intrude into that space. Also, the depth of the side cabinets is restricted as well. If you use the free liner, you may need to supplement it with stainless spacers at the sides and rear both.

You need to study the exact specs of the rangetop. And the liner. And talk to your local code inspector. He will have the final say if it meets his approval or not. Better to engage his opinion during the design phase.