What kind of board do you use for outside walls for a loft room?

For the outside walls of a loft room, it's common to use insulated wall panels or moisture-resistant plywood, often treated to withstand weather conditions. Additionally, exterior-grade OSB (Oriented Strand Board) can be used as a structural sheathing layer, providing stability and insulation. It's essential to ensure proper weatherproofing and ventilation to protect against moisture and temperature fluctuations.