The Certass TRR Window Energy Rated IGU scheme is unique, trusted by some of the biggest names in the industry and is fully compliant with CE Marking and Building Regulation requirements.


Our WER labels are designed to be consumer friendly, avoid technical jargon and use easy to follow graphics that aid the sales process. Our label has been designed to make your, and your customers, marketing stand out.

With the Certass TRR IGU Scheme, you can have unlimited WER labels in your company name, thus ensuring the promotion of your business identity in the marketplace. It also ensures that you can best meet the needs of your business by easily changing window specifications.

This will allow your business to lead and secure the best and most competitive deals available to you at any one time, meeting your customer expectations whilst placing you in a better position to take full advantage of new technologies.

Our unique consumer friendly WER label is easy to understand with simple to follow graphics. The unique light energy transmittance and heat retention graphics assist in the sale of triple glazed units. Often triple glazed units do not perform well with the WER rating methodology as light transmittance is reduced due to the third pane of glass. With our simple to follow graphics the beneficial effect of the improved U-Value is demonstrated clearly for all to see.


The Certass Thermal Ratings Register offers the lowest cost, highest value WER Scheme in the industry. We also offer a corporate IGU Scheme; this allows you to create the labels on behalf of your installer customers, helping to tie them to your business.