Roof reflection simulation

edit

Hi. I'm analyzing retrofit measurements in roof for diminish the energy demand. I analyzed 3 main alternatives: cool roof (changing solar absorptance), Isolation (adding new layers in the construction element) and shading element above existing roof. I thought the combination of this measurements will diminish the energy use for cooling, but it is the opposite. Any combination with reflecting roof doesn't improve it's energy performance. Is it logical results?