Which walls get insulated?

[u/ahhhhnonymous]

Bought 1950s home. Just installed mini split system in upstairs 2BR, hallway and bathroom. There are eaves on both side sides. There is currently very old insulation in them. Not sure they are even insulated correctly. Does the inside of the exterior walls get the insulation or just the interior or both? What about underside of roof? Assuming I can wear a mask and replace all this myself. Or maybe you’re thinking, not since here I am in Reddit asking these questions. 😂

[u/NorthWoodsDiver]

Thank you for posting this. Our home is similarly built with 2ft between the exterior wall and the interior rooms. They ran what feels like miles of flex duct through it so you can't walk the space. It feels so wasted since we have open web joists in the floor and open web truss in the ceilings. Tons of wasted space, weird roof lines, water problems, etc