When sourcing wall materials, you must prioritize Fire Rating (Class A or B1) to ensure building safety compliance. For interior panels like WPC or PVC, check the Formaldehyde Emission Level (E0 or E1 grade) to meet environmental health standards. Additionally, evaluate the Density and Thickness; for example, fiber cement boards should have a density of ≥1.2g/cm³ for structural integrity, while acoustic panels require a specific NRC (Noise Reduction Coefficient) of 0.7 or higher for effective soundproofing.