According to Italian law (D.M. 26.06.2015)
Ministerial Decree (D.M.) 26.06.2015 is the legislative instrument on building energy efficiency currently in effect in Italy and has been supplemented with content concerning how buildings behave in summer. Appendix 1 to the decree expressly indicates:
"3. In order to limit energy requirements for air-conditioning in summer and keep indoor temperature down, and to limit overheating in urban areas, the use of certain systems in building roofing structures must be checked for efficiency in terms of cost-benefit ratio, more specifically:
a) cool roofing materials, to have a solar reflectance rating of at least:
- 0.65 in the case of flat roofs;
- 0.30 in the case of pitched roofs;
b) passive HVAC technologies (including by way of example, but not limited to, ventilation, green roofs).
The above-mentioned checks and assessments are to be documented in a technical report
as explained in section 2.2."