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·K)|
|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: