There are even tax benefits for doing this in the USA. https://www.energystar.gov/about/federal_tax_credits/roofs_m... We decided to not use shingles on our new roof but go with silver galvalum. Galvalum does not provide the initial reflectivity but over a 5 year period shingles lose much of their reflectivity https://homeenergysaver.lbl.gov/consumer/help-popup/content/... https://web.ornl.gov/sci/buildings/tools/cool-roof/ ...there are many other resources out there. It made a huge difference in our home in rural Georgia.