Many companies state u-values of 0.6 W/m2K, but they are readings from the centre pane of the glass and do not even include the frame. What is shocking and unregulated is that a company can state 0.6 W/m2K as a u-value yet when calculated properly in the horizontal and including the frame, the values can shoot up to 1.6 W/m2k or, in the case of one Leicester company, over 2 W/m2K, both of which would not pass planning permission.
Sunsquare have always offered genuine U-value calculations and offer certificates with every skylight if required. Sunsquare are allowed by the BSI to calculate and publish U-values on their own products as well as other companies, which is where we know the reality of the dishonesty of most in the industry.
We are now able to offer the lowest U-value products on the market without using triple or quadruple glazing at a relatively standard price. We have been working with glass technology companies to develop a whole product U-value that can be relied on and not only conforms to building regulations, but would sit comfortably in a passivhaus project. We are able to offer a whole product (including upstand) U-value on our fixed products of 0.662 W/m2K which we believe is the best U-value in the world for flat roof skylights and 1.01 W/m2K for our opening products, again including frame, glass, upstand and calculated in the horizontal.
What is shocking is that many people are buying products based on U-value and actually not getting much more than one would get from a single pane of glass due to poor frame design and cold bridging. We are not the cheapest company in our industry, but we offer Kitemark honesty and re-assurance, which is unique to Sunsquare. Please, when comparing products, ask for a whole product U-value and not simply the centre-pane U-value. If we at Sunsquare simply gave our centre-pane U-value, we would be offering skylights with a U-value of 0.38 W/m2k, as an example.