The WWA said the A+ rating for standard softwood timber windows and A+ and A ratings for aluminium-clad windows show that WWA specification windows are more environmentally friendly, offering a longer planned service life and lower whole life costs than PVCu alternatives.

All WWA standard softwood timber windows for commercial and domestic buildings are rated A+.

Powdercoated aluminium-clad softwood windows with an internal water-based translucent coating are rated A+, while those with an opaque internal coating are rated A.