Plus-energy windows with U-values of 0.8m²K and less were developed in 2000.
Plus-energy windows contribute to a low-impact balance by capturing more warmth than they lose. This is due to new composite materials with tremendous insulation capacities, strength and durability. As a result, less bulky, larger-scale constructions are possible.
Plus-energy windows with double- and triple-glazing typically have U-values of about 0.8; these include VELFAC 200 E and Rationel AURAPLUS.