Thermoplastic polyolefin (TPO) is a type of roofing membrane that has recently become popular because it often costs less than other types of roofing. Mainly used in commercial and industrial applications, the material possesses thermal and reflective properties that make it an attractive option for improving/enhancing building energy efficiency. Relatively new on the scene, the quality and efficiency of TPO roofing can often vary widely due to differences in the way manufacturers formulate the product.