EuroWindoors infographic shows that energy balance based window replacement requirements are only implemented in a few EU Member States. The energy balance approach considers beside the U-Value (heat loss) as well the g-value (solar gains). The solar gains must be considered in the revision of the EPBD also for replacement.
EuroWindoor Infographic on Energy balance based window replacement requirements in EU Member State
[more information about EPBD in the section " Energy Performance of Buildings of the activity "Energy efficiency”]