There is a lot of discussion about “cool” roofing. Most of the discussion talks about how a roof that reflects most of the sunlight off the waterproofing layer of the roof is more energy efficient than a roof that doesn’t. So – white vs black. But it’s really white membrane (or coating) versus gray (gray membrane or even rocks) versus black (black EPDM or maybe modified bitumen). White roofing proponents make statements saying white is good for all environments. The opponents say basically there is a line across the country, north of which more energy is used heating than saved in the summer cooling. Another possible point in favor of white roofing is to cool cities in the summer (the heat island effect) despite any possible energy dollars lost in the winter. The US Dept. of Energy has a site that can also be utilized to see the differences of white vs black – www.ornl.gov/sci/roofs+walls/facts/CoolCalcEnergy.htm. Our advice would be to install more insulation in multiple layers before you start looking for savings with a white or black waterproofing layer. Do some of your own research – with multiple sources – and then see if you have a preference.