If they are insulated properly (lots of roof insulation) it also keeps the heat out. I'm building a house and last week it reached 32c here, inside got no warme

If they are insulated properly (lots of roof insulation) it also keeps the heat out. I'm building a house and last week it reached 32c here, inside got no warmer than 23c on the upper floor. I don't have AC installed yet, just HRV.