I’ve inspected a new home with an attached garage. The attic area for the garage is open to the area over the living space. There is no top vent on the garage gable, but one lower vent. I reported lack of top vent on this gable.
The builder responded saying that the NFVA calculation only applies to conditioned spaces, however; one of the lower vents used in their calculation is actually located in the unconditioned space of the garage. “Per code attic space that is over conditioned space is what we look for when running our calculations. What you will see when you open the file is that this roof requires a few things to be code compliant”
The issue is that the unconditioned garage space adds a considerable amount of area and would change the calculation from approximately 50% in and 50% out to having insufficient output capability.
Is the builder correct that the building code ignores the area over unconditioned spaces even though the attics are connected and essentially one space? Is the calculation affected because one of the lower vents is in the unconditioned area?
It’s been my experience with several warranty inspections for new homes with a similar configuration that cracks form in the garage ceiling or the owners complain about how hot the garage gets.
Pictures show the garage gable with no top vent, one bottom vent used in the calculation in the garage area.and the builder’s engineering calculation