Blowback from Adding an External Vent to a Condo Unit

K.R. from outside of Connecticut writes:

Dear Mister Condo,

I am on the second floor of a two-story condominium. I am in the process of planning a kitchen renovation, and as part of the project I would like to have an externally-vented exhaust fan. The range hood that I currently have simply blows the air back into the room, but I had assumed that I could connect it externally if I wanted to. I have been informed that to vent it to the roof I will need the Board’s permission and I may also need to file an “obligation to maintain” with the County so that I would be responsible for any future issues (eg. leaks).  Also, I currently have an externally-vented bathroom exhaust fan, so I don’t see why this would be treated any differently. My questions: Aren’t externally-vented kitchen exhaust fans required by code? Wouldn’t a non-externally vented fan create health & safety concerns? Are there any legal considerations if they deny my request?

Mister Condo replies:

K.R., generally speaking, all modifications to your unit are subject to Board approval. Anything that you are doing that modifies any common element is strictly under the Board’s control and installing an externally-vented exhaust fam for your kitchen will most certainly require their approval. Be sure to get all the approvals needed BEFORE starting your project because the Board can force you to remove the installation if they do not approve which can cost you dearly. I am not an expert on HVAC or ventilation issues but I do know that exhaust fans that vent internally and clean the air via filter are fairly common in many condos. That doesn’t help with your odor issue if you are cooking but the filtration system does help. My guess is that the condo unit was built to the code at the time for exhaust fans. If that code did not call for external ventilation, there was no foul on the part of the developer. If current code does call for that kind of ventilation, that could be used in your argument to persuade the Board to allow it now. That being said, ask politely and hope for a good outcome. Don’t be surprised if the request is denied. If they approve your installation, they are opening themselves up to others and then there becomes a whole new issue of external vent conformity and maintenance. Good luck!

4 thoughts on “Blowback from Adding an External Vent to a Condo Unit

  1. It can have an effect on many areas of the unit, as well as common elements, ie as grease builds up on the roof who is liable for proper cleaning, who pays the additional costs in heating and cooling, it can unbalance the air flow within your unit, etc… .

  2. I am a building inspector and yes, new construction requires an externally vented range hood. If you pulled a permit you would have been told this. Granted I am in California, but most states use the Uniform Mechanical Code. Since you are in a condo, and the utilities and structure behind the wall is HOA responsibility, it is legally on the HOA to provide the ducting and penitrations. Also a kitchen vent should be through the wall, not to roof because of the grease issue. Also check with the local code enforcement agency on distance required from windows and doors.

  3. We live on the first floor of a 5 floor Florida condo building. Both of our bathrooms have faux ceiling exhaust fans. I was rather shocked to find that out after I removed the cover on one of them, and also finding out there is no exhaust pipe to connect to. The condo building was built in 1985. And I’m pretty sure the HOA will not allow any drilling an exterior vent.

    I know there are ventless exhaust fans on the market, but I doubt their effectiveness for removing smelly air! So, my dumb question is, can the existing plumbing vent pipe be used for an exhaust fan?



    1. Ray, that is a really great question and shows what a creative problem solver you are! I am not an expert is plumbing but I did a quick internet search and found two different articles on why you shouldn’t do this. Both indicated that it creates a possible back-up of sewer gasses. I can’t imagine you would want that, regardless of whatever other smells you are trying to vent! Also, there is likely a code issue. You should likely check with a local plumber or HVAC expert and ask them directly. My guess is they will agree with my synopsis. All the best!

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