If painting in your facility or shop is a regular occurrence or standard production, yes you should have a paint mix room at the very least. This is the bare minimum as mixing paint and storing tools used to mix and cleaners etc. creates a potentially hazardous situation in any building. The only other thing you may consider is a paint storage room that is designed for containment and housing paint and related materials. A paint mixing room gives your shop a safe and ventilated place to keep some of the most volatile products used in the painting process. The mix room is supposed to be ventilated ALL THE TIME so don’t turn the fan off at night!