IMO no one needs a 48" range and for sure not one with a griddle you pay a fortune for . I run a catering biz with a 36" range and a $25 griddle thta spans 2 burners and has done 1000S of panckaes and eggs for years with great success . I assume this is a gas range with electric oven not my fave either I much prefer to bake in my gas range for many things like pizza, bread any yeast dough actually. I do have double wall ovens that are electric . All the ovens are convection. I do hope the architects is not designing the kitchen most are not good at it. To get great free advice here from actual KDs post a to scale floor plan of the space show every window , doorways where those lead done on graph paper to make it easy. Show every measurement clearly post here in jpeg format in a comment DO NOT start another post . Once the appliances are bought and on hand you design the kitchen IMO since often even now deivery times can be craazy so sometimes a cahnge of mind .

I assume you are also the OP at some level. Yes 36" above the range is good it will not bonk your head . I think it needs to be at least 54" wide for the hood no matter what you make it outof . If this is agas range you will need huge CFM and MUA so make sure you factor that in too.

As long as the hood can overlap the rising and expanding cooking plumes' effluent, it can be at any height. Because each cooking plume expands as it rises, this implies significant growth with height, and there is also the issue of cross drafts and air turbulence from moving persons on plume disturbance adding to the plume growth with height. 36-inches is a nominal height for residential cooking, with 48-inches typical of commercial cooking hoods.

One wants the hood to not intercept one's head, but ducking is also a strategy. This is complicated by front-to-back depth, which one wants to be large for full plume capture, but which tends to put the hood into the cook's head proximity. I think a 36-inch height over a 36-inch counter will work with your husband's height, or you can stretch another inch with a large enough insert. Note that hood lamps should be LED, or the cook will need a cap if he is too close.

The size of the hood wood cabinetry is not the driver here, it is the insert's entry aperture. This needs to be at least 6 inches wider than the cooktop at 36 inches height, so you may be OK. Front to back depth is marginal, I think, although there aren't a lot of options for really deep inserts. So smoky cooking on front burners may not be fully captured and contained.

A hood against a wall may be aided in capture performance by side cabinets and the wall constraining the plume expansion. I would consider the possibility of mounting the insert so it is farther from the wall ( use a stainless steel plate at the back) such that the cook's side of the aperture is at least 3 inches out from the edge of the grill or largest pan to be used on a front burner.

Whatever the entry aperture, assure that the air velocity into the aperture is at least 90 ft/min at full power. This requires 90 CFM per square foot of aperture. Further, the rated flow rate of the blower needs to be about 1.5X times that value (as a guess) to overcome pressure losses in the baffles, ducting, and imperfect make-up air (MUA).

I strongly recommend an MUA plan before purchasing anything related to the hood system so you know you can accommodate MUA appropriate for your intended cooking.

Feel free to ask follow-on questions, but searching out and reading hood topics here will be useful.

Thank you. I wasn’t familiar with MUA so did a quick google. Our house is 1700’s and not remotely airtight 😃. But I will make sure to ask the questions when we get the hood insert options from where we are getting appliances.

You will still need to follow code

I have to follow code, we are permitting a major project.

The thing always left out?

You must begin running the fan on any hood, well before you actually begin to cook.

Yes.......even this hood: )

While a leaky house will have a lower pressure drop to the interior at the roughly 1000 CFM you may be pulling than a tight house would, your hood system will still be pulling dust and humidity through the walls, and it may, depending on your combustion appliances, if any, and where they are, back-draft one or more of them causing a potential carbon monoxide hazard. This is the basis for the MUA code.

The fact that restricted flow MUA will also restrict the hood flow is secondary to safety, but primary for hood performance. So you may appreciate that the hood system, the MUA system, the elements of the HVAC system, and the house architecture constitute a system of systems that need to work in concert.