not quite the same scenario but hope this helps. i remodeled my 1942 yr old kitchen (full demo to the studs). ventalation was just a pipe in the ceiling, think it was for an old gas stove connection, not ventilation by today's standards. the GC did the work, was not major but you need to understand BTU's for the stove and do the right calculations so you size the system right. there was a cost to increase the diameter flue pipe ducting from 6" to 8" diameter through the attic and connect to roof vent. the roof connection was already there, we just needed to swap out with new wider dimension pipe to accomodate wolf range i selected. i paid $1375 to do the work described as well as to mount the new range hood plus the hood itself cost approx $1050. keep in mind this was one element of a full kitchen remodel.

i think it will largely depend on the layout of the house you are considering. if there is free open attic above the kitchen it can be easy (my situation). another layout without the headroom above could be more challenging.

good ventilation makes a world of difference, so glad we did the right research!

We put in real ventilation during our renovation. The range hood is about 7 feet from the exterior wall. The new pipe had to run up into the ceiling, turn a corner, and run between the joists out to the exterior wall. We were fortunate that the joists were running the right way. Also, we had to do this when no cabinets were in place so that the ceiling could come down (the pipe runs directly over the cabinets as the range hood is between cabinets). For us, the joist direction worked out and it was not a very complicated project. And it has been fabulous to have real ventilation.

At a summer house I know, there is a downdraft vent that is surprisingly effective-- it really sucks down the smoke and steam. It is an old Jenn Air. The burners on the range don't work reliably any more but the downdraft is great.

Thanks. Almost all of the houses we're looking at are 2 stories, so sadly it probably wouldn't be as simple as babushka_cat's situation.

It really amazes me that people go to the trouble to put in these expensive new kitchens in really nice houses, but don't do the ventilation right. It's as if it's all for looks, but you're not expected to actually cook there.

I just did this, my scenario was very similar to waterdamage's, and the cost was similar to babushka's (maybe even a bit less). I imagine that it may be a bit different if the cooktop is on an island though, a bigger expanse to travel, and you will obviously have to go to the side to vent out instead of going directly up. I have only just now had use of my cooktop so I can't really speak to the effectiveness of the hood, although the one time I used it to saute some fish, it worked just fine. But to answer your second question, yes, for some the kitchen is just a showpiece. If it is something that is really important to you and you have the luxury of options in your price range, I would put full emphasis on the layout and functionality of the kitchen. Imagine how you would work and cook in the space. You can make many adjustments in a home that are far less costly than having to do a kitchen remodel right off the bat! Good luck!

In an easy to do situation, you might be taking 2-3K above the cost of the actual ventilation. In a difficult situation, you might be talking 5-7K to impossible to do given the layout of the house. That is above the cost of the venting itself. Island ventilation is more expensive than wall ventilation by at least double.

I would either be looking at kitchen that needed a gut remodel or else ones that were already completed to your specifications. It would be easier to just put in place the kitchen you want out of an old dumpy kitchen than it would to change something so fundamental in an already completed brand new kitchen.

Well, $10K is a ton of money to spend on putting in ventilation, but it's still way, way less than I'd spend on a complete gut kitchen remodel. And that's not even factoring in the stress of managing the project. I've been through enough of those in my day. So I'm not sure it's such a clear decision. If the kitchen is otherwise great, I'd be inclined to just shell out the $10K or whatever and be done with it. Especially if the rest of the house is what we want. There are a lot of variables involved.

I have had to retrofit a couple. One was in a house where we moved the kitchen, there was a linen closet above, so with a bit of a turn we got it through that, through the attic and out.

Another I am working on is your situation. It is going to go to one side and through a soffit and out, since the joists run the other way. And upstairs is the middle of another room, no convenient closet. The soffit just has to be designed so it looks intentional not like a retrofit.

All situations will vary but you will be able to get a general idea by knowing which way the joist run and what obstructions or pathways are available upstairs--and sometimes this can be told by looking or asking.

In my neck of the woods everything is a row house so the joists run almost without exception from side to side while the "outside" and windows are front to back. (So they generally run the wrong way.)

Besides the necessary venting layout, you better also check the local codes. If you are in a cold, northern climate, you might be required to add make up air for any venting system, whether there was one in place before or not. I did a gut reno, and added venting which was straight up a wall through the attic to the roof. But I had to install heated make-up air, which cost more than my range and hood combined.

I would NEVER consider buying a house with an island range/cooktop and no ventilation. Just a total PITA to do it right.

Our situation is different than yours, but the way we did it was not at all a big deal. We swapped out a recirculating under-cabinet hood for a ducted one. It's a one-story house with an attic, and our handyman just ran the duct up through the roof. We have an electric stove, so an off-the-shelf hood from the big box was sufficient and make-up air was not an issue. I can't remember what the installation cost but it was not much in our case. Hiring an electrician and a roofer, which perhaps would be the more correct approach, would have cost more of course.

I haven't used a downdraft so can't compare, but ducted vs (old crummy) recirculating is simply night and day. I'll never do without ventilation again. My mom doesn't have it and doesn't see the need. Oh well. (She has an electric stove too so at least there are no combustion byproducts floating around.) I imagine it can be hard to look past a shiny beautiful new kitchen to notice things like layout and functionality, but it sounds as though you have the right things in mind. Good luck with the hunt. I wouldn't want an island cooktop with no ventilation either and I would also be skeptical of the downdraft until I saw it in action.

Here is our experience: it will not necessarily be predictive of your experience.
A few years ago (pre kitchen renovation) we did a retrofit to put in a real venting hood.
The 8" diameter vent ran about seven feet through a ceiling joist cavity
to vent out of the house.
The labor cost 1500 dollars and took the HVAC worker a full 8 hour day.
We live in the northeast where labor is always expensive.
That did not include the cost of patching the plaster ceiling or the cost of the vent hood.
Live wire oak's estimate (see above) seems right for a relatively easy situation.
Again, every situation is going to be different. But you just wanted a rough estimate.

in the appliances forum you will read often of cases where people install kitchen exhaust ducting in a house that doesn't have it yet.

Thanks all, this is very helpful.