If it happened to me, I think the fair way is for you to pay the cost of the system had it been installed before the drywall went up, and the contractor absorbs the rest. This is one of those situations where something was overlooked. Unless you decided at the last minute that you wanted a 1200 cfm hood, and your contractor did not anticipate you wanting that monster. If you have small children or pets, please keep them away from the hood while it is running.

How did you determine that you need that many CFM's? You might actually be able to get by with less, and save yourself some money on the hood and not having to install an expensive makeup air system.

Also, some hoods with higher CFM's have jumper switches on them that will limit the CFM's to a lower rate to pass inspections. You can do that, remove the jumper after inspection, but just remember to open a window when you crank that baby up.

Mike lamb - our Thermidor stove is a lot of BTUs... not handy off hand. We know we can “open a window” but feel that it should have been done right in the first place. Code seems to support our view. We fee the contractor let us down but not having even put this in front of us, but my husband and I disagree on how liable that makes the contractor so we really appreciate your input!

The question I would ask is was the code approved prior to the permit being issued? If so the builder is responsible. If not approved prior to the permit the builder is not required due to the permit being issued under old codes.

Fred - the mind reader thing doesn’t apply in this circumstance although I totally see your point. There have been other situations like this in te process where we give him the benefit of the doubt for that reason.

Back story is that we met te GC when we had considered buying a spec home from him. We asked him if he’d build the same house after we acquired our own lot a few months later. (Yes). We worked with his same architect for MINOR modifications - no change to the kitchen or mechanicals. In fact, the contractor set the budget using the invoice from the appliances in the previous build and that is indeed the range and hood we selected too.

A MAKE up air system was never installed in the previous house or any of his other similar homes. I assume for the previous house - either the town has been lax about it or ??? Well, we did upgrade our insulation so perhaps our tighter wrap may be a difference. The stove and range was and will be installed before CO....

Altogether, we feel that we weren’t given guidance that should have been well within their subject matter expertise and experience - GC, HVAC, appliance sales person or architect. Especially if you are marketing yourself to build houses at this price point that are likely to have upgraded appliances.

It turns out town code backs us up although I see why the town approved our plans in the initial stages since they wouldn’t know about our appliance selection.

It seems to me that there’s a perfect storm of heavy duty vents and increasingly tightly wrapped homes that is making all of this somewhat of a new problem but still... it should have come up.

Everyone’s feedback is awesome! Things can see get hairy. It’s not even clear to me how much $$$ is at stake. Anyone?

Unfortunately, It is not that extraordinary to find that none of these people who should know better, don't. I am constantly surprised by how many GCs and architects wait for the underpaid inspector to tell them what the code changes are instead of looking it up themselves. The excuse is often that they would not want to have to provide anything new and extra that their competition is not also forced to do by the inspector :-/

If it is the GC's architect, and the GC has a hand in what is included on the plan and construction details, then the buck should stop at the GC, as long as the appliances and range hood are stipulated elsewhere in the contract. However, the contract would only specify exactly what was allowed to be done in the previous house you are copying.

"Well, we did upgrade our insulation so perhaps our tighter wrap may be a difference." - This can make a big difference, especially when combined with newly updated energy codes that force them to recognize the MUA requirement. There is the 400/600 PRESCRIPTIVE CODE, or you can used the "do the math" alternative. http://www.broan.com/tools-landing-page/range-hood-make-up-air-damper-specifier It sounds like you really REALLY NEED to also look into the newer whole house mechanical ventilation requirements for your area as well. To some point, the two systems may be able to be combined.

"although I see why the town approved our plans in the initial stages since they wouldn’t know about our appliance selection." - And, it is above the pay grade of the one who goes out to the job and signs off the card at final... or nobody has pointed that line of the code out to them... since a person can make WAY more in the private sector, it tends to be a variant of the old saying, those that can't do, inspect and criticize.

"making all of this somewhat of a new problem but still... it should have come up." - It still amazes me how often this still comes up on Houzz.

"It’s not even clear to me how much $$$ is at stake." - It can depend on where you live and the climate, how they interpret or amend the code, and things like what type of water heater, furnace, fireplace, radon,.. you have. If your furnace and water heater are (high efficiency) direct vent with PVC vent pipes, it may cost less. (But, you may still need to open a window at higher fan speeds for the best efficiency)

Fred thank you for your contribution! We will pour over this information and perspective.