I'm designing a 10,00sf single story commercial building with 3 suites, type 5 construction, with flat roofs pitching 1/4" / foot to one side. All HVAC equipment will be located in a central location surrounded by a 5' screen wall and accessible by a roof hatch coming up from inside. I'm confused about the IBC and OSHA requirements for parapet heights. Given that this equipment will be far greater than 15' from the roof edges and within a screen wall, do I need to (or should) provide parapets at the roof edges? If so, do they need to be 30" high? Am I ok with a design where there are minimal parapets at about 12" - 24" high? Thanks for the help.