Minimum room size requiring ventilation?

Anyone out there know the smallest sized room that requires a duct for ventilation? The porch I inspected yesterday was completely enclosed, no windows could open (they were made to not open), and was around 90 square feet in size. Should there have been ventilation?

r u a code inspector
section r304 covers this
you can make any recommendation u want
just make sure you have fact based info to backup you bs

I’m not looking for a code to enforce. Just wondering at what general point a room needs ventilation, so I can base my recommendation on something besides my feelings.

Are you saying ventilation, like fresh air from an open window, or a supply of conditioned air from the HVAC?

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The proper term is conditioned air not ventilation.

It is not considered a living space unless it has a heat source, so an enclosed porch is perfectly fine without a conditioned air source or heat source, it just shouldn’t be included in the living area (sq. ft.) of the home.

Don’t confuse “ventilation” from “conditioned air.”

Opening the doors would provide “ventilation” of the room, although you could mention in your report that the windows were fixed if you wanted to give your clients a heads up.


Sorry all. I should have used the term “conditioned air”.

Kevin-your response makes sense. I’m clear now. Thank you

Which means it will not be counted as square footage. It could affect the appraisal, but that’s above our pay grade.

Exactly. :+1: