That’s the way. My interior walls all have insulation. Drywall guys didn’t like it. I also insulated the garage ceiling , which almost nobody does. Cast iron tub because what difference $250 in material will make when paying $1000 in labor regardless of the type of tub? Lol I went with better materials and people love my house. It cost me 400k to build this way, builders grade was going to cost me almost 500k if I hired a GC. house is 3/3.5/2 2633 SF, vaulted ceilings, custom cabinets/closets, quartz countertops with waterfall island, toto fixtures, jetted cadt iron tub fir 2 on master bath, 18 x 8 garage door, solar panels, paver driveway for 6 cars.
What I’m reading here has mostly to do with energy efficiency and not with safety.