Is it time for triple?

Andrew Charlesworth
Andrew Charlesworth

Andrew Charlesworth, technical director of profine UK and Kömmerling, talks about the opportunities for triple glazing today, with the government mooting a U-value of 0.8 W/(m2K) in just a matter of years. But how would the industry cope?

The new building regulations have had an impact on the industry both in the residential and new build sectors and our own extensive testing programme has seen us declare that all Kömmerling 70 windows achieve a 1.2 W/(m2K) U-value as standard with a 28mm IGU and a polysulfide sealant.

Importantly, it’s also the same standard that our new Greenline platform also achieves.

But what’s next? As I pen this feature article, Rishi Sunak has just concluded his speech at COP27 urging a global push on green growth and that’s something that we’re already striving towards with our new joint venture, Profine Energy GmbH. But closer to home we must consider current and future product platforms and whether, as an industry, we will ever revert back to tilt and turn windows?

The casement window is relatively unique to the UK and we have to consider how far it can be developed technically. As a global systems powerhouse we have more resources than many and a reputation for product engineering excellence – or #TechnicallyBetter as we describe it.

Our 70mm platforms are good, but we also have 76mm and 88mm platforms, along with Warmcore that was designed with the future in mind right from the outset. This ensures that our customers have access to technically-led PVC-U and hybrid systems for today’s and tomorrow’s changing market requirements.

Kömmerling 76 is designed with the future in mind with casement, tilt and turn and also flush sash options available. Due to glass limitations the double-glazed variant achieves a U-value of 1.2 W/(m2K) using a standard 28mm IGU, but as a platform that can accommodate triple glazing, it can achieve U-values as low as 0.78 W/(m2K) with a casement window and 0.84 W/(m2K) with a tilt and turn. It’s also part of a pan-European platform and so there are a wide range of ancillaries, trims and foiled options amounting to over 100, along with inward and outward opening door options.

Warmcore has also been designed with triple glazing in mind and the casement, flush and tilt and turn variants all achieve a U-value of 0.8 W/(m2K) with a standard 44mm IGU. Single, double, patio and bi-folding doors are equally impressive performance-wise boasting a U-value of 1.0 W/(m2K) with the same glazing specification. These figures are particularly impressive when you consider that Warmcore is based on a 70mm platform.

There are further considerations when it comes to hardware and the additional weight of a triple glazed unit, but we are suggesting that manufacturers and installers should start looking at the implications of heavier glass units in terms of transport and installation processes and practices.

Frame depths will inevitably get deeper over the next five years and dare I say it following the European model when it comes to energy efficiency.

It’s also a time in which fabricators need to assess their suppliers as the next change in building regulations, which could be as soon as 2025, will have far greater implications than the last changes. This might coincide with a change in government too, including the potential for an even bigger commitment than ever before when it comes to climate change.

Triple glazing is here to stay and is likely to be the long-term solution to improving the energy efficiency of all private and public buildings. Deeper product platforms will also come into play as will hybrid systems such as Warmcore.

But work is needed prior to future changes for the entire supply chain, so that we’re fully equipped to make the transition from double to triple.