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·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:
