Energy Ratings

Modern timber windows are designed to be energy efficient in order to satisfy building regulations and carry a CE mark. Energy ratings are required to be measured independently and are given as u-values.

Custom Timber Window products are highly rated with typical values.

Material Energy Rating u-value in W/(m2┬ĚK)
Standard 4-16-4 Pilkington K-glass double glazed panel, Low E/16arg/4Ug 1.1
Whole frame Softwood (Pine) with European Oak Cill 1.5
Whole frame hardwood European Oak 1.6

Full details of measurements can be seen for casement and sash timber windows by following these links: