Blonde Girl Posing In Front Of The Window

Material - thermal resistance - Durability - Maintenance - Cost - Recycled content - Comment
Wood - very good - variable - high - high - low - shrinks and swells with humidity changes
vinyl or PVC - very good - good(1) - low - low - very low
Aluminum - bad(2) - good - very low - low - typically >95% - used in most large structures