An excerpt from Los Angeles’ recent update to its green building code that includes a reflectivity requirement for new and replaced residential roofs.  The ordinance requires low-slope roofs to have a minimum three-year solar reflectance of 0.63 and a thermal emittance level of 0.75.  Steep slope roofs must have a minimum three-year solar reflectance level of 0.20 and thermal emittance of 0.75.