Rigid foam insulation options for my conditioned crawlspace

I’m building an ADU with a conditioned crawlspace. The energy guy says I need R-20 on the walls. I’ve read here that I need to cover foam board insulation with… I’m building an ADU with a conditioned crawlspace. The energy guy says I need R-20 on the walls. I’ve read here that I need to cover foam board insulation with…Read MoreGreenBuildingAdvisor