Unlocking the triple glazing opportunity
After picking up the prestigious G24 Award for Machinery Innovation, Forel used its platform at the 2025 FIT Show to present its series of groundbreaking ‘new generation’ IGU Lines to UK glass manufacturers, fabricators and installers. The innovative machines produce ‘skinny triples’ which deliver lightweight, high-performance triple glazed units compatible with existing 70mm window systems, promises to remove many of the long-standing obstacles that have restricted wider adoption of triple glazing in the UK.
Glass Times editor Luke Wood caught up with Brian McDonald, CEO of Forel UK & Ireland, to find out more about this potentially transformative technology.
Triple glazing has long been heralded as the next step in improving energy efficiency for UK homes. But despite rising demand from environmentally conscious homeowners and the looming Future Homes Standard, its adoption has been slow.
The challenges are well known. Conventional Triple-glazed units are heavier, more expensive, harder to manufacture, and more difficult to transport and install. The additional weight also places greater strain on window and door hardware, requiring upgraded and costlier systems. All of this adds friction to supply chains, complicates production for IGU manufacturers, and dampens enthusiasm from installers.
“Installers, in particular, have been resistant to triple glazing, especially when it comes to handling large units,” explains Brian. “Even with modern lifting equipment, the weight makes jobs harder, longer, and potentially riskier.
“There’s also been a practical limitation with the design of the windows themselves. The majority of UK window systems use 70mm profiles, which have been stretched to their maximum in terms of energy performance. While clever glazing and coating technologies have helped, system companies have struggled to achieve meaningful improvements to U-values without increasing the profile depth – adding further cost, complication, and aesthetic compromise.
A smarter approach
So how can IGU manufacturers, window companies, and installers meet the growing demand for energy efficiency without reinventing the wheel or overhauling established window designs?
This is precisely the question Forel set out to answer.
Working in partnership with global industry leaders, Forel has patented a manufacturing process that allows for the production of lightweight triple-glazed IGUs using a thin centre pane. The innovation was first introduced to the global market at GlassBuild America, generating considerable excitement, before making its UK debut at the FIT Show earlier this year.
At the heart of the concept is a simple but effective change to the structure of the triple unit: the centre glass pane is encapsulated within the IGU, allowing the overall unit to be produced with a single outer seal rather than the traditional double sealing process.
“Encapsulation is a game changer,” Brian explains. “By using a 1mm or similarly thin centre pane, we’ve drastically reduced the weight increase usually associated with triple glazing. Our system delivers an increase of just 2.5kg per square metre over an equivalent double glazed unit – roughly a 12.5% uplift, depending on unit size. For installers, that’s manageable.”
The result is a triple glazed unit that’s not only lighter but can also be produced at a similar speed as a standard double glazed unit. Production bottlenecks are eliminated, costs are reduced, and manufacturers gain the capacity to meet large-scale demand efficiently.
Seamless integration
One of the standout features of Forel’s HighTech & HighSpeed Lines, are their compatibility with the systems and processes already familiar to IGU manufacturers in the UK. The technology uses a flexible spacer system – an approach already widely adopted in UK production facilities – and requires only a single secondary seal.
“Critically, this means that IGU manufacturers don’t need to fundamentally change how they operate,” Brian continues. “For some manufactures with existing Forel lines, we can offer modifications to accommodate skinny triple production, meaning you can future-proof your business without rebuilding your entire factory from scratch.”
Even for those investing in new lines, the ROI potential is significant. “It’s about unlocking demand,” Brian says.
“Homeowners are crying out for meaningful energy efficiency improvements, especially with ongoing concerns about energy bills and broader geopolitical instability affecting global fuel prices.”
The application of skinny triples to 70mm window systems is another breakthrough. By offering triple glazed units up to 36mm thick which is generally regarded as the maximum unit thickness compatible with most systems, manufacturers and installers can now achieve U-values closer to or even below 1.0 W/m²K – approaching the performance levels expected by the Future Homes Standard – while still working within the frame dimensions they know and trust.
Capitalising on demand
The reaction to Forel’s High Speed Line at the 2025 FIT Show has already confirmed the market’s appetite for innovation. Installers and major installation companies serving the new build sector were among those keen to learn more about how and when they could start using the new system.
“We had significant interest from both fabricators and installers,” says Brian. “For installation companies working in the new build sector, this offers a way to meet demanding new energy targets without adding unnecessary complexity or cost to their operations.”
It’s also a major opportunity for UK housebuilders. With higher performance glazing available that fits into established designs, housebuilders can deliver energy-efficient homes at scale, offering homeowners a real return on investment through reduced energy bills and improved comfort.
For fabricators and IGU producers, it’s not just about meeting current market demand – it’s about future-proofing operations. The need for more efficient, sustainable building practices isn’t going away, and with the first UK installations of Forel’s High Speed Line set for later in 2025, those who move early will stand to benefit the most.
A new era for triple
Forel’s innovation represents what could be a turning point for triple glazing in the UK market. Recognised by the G24 Awards and reinforced by a successful launch at the FIT Show, the company is now building on that momentum by working closely with glass suppliers, fabricators, and installers.
“The UK glazing industry has always been quick to adapt when the right solutions come along,” Brian concludes.
“This is one of those moments. With skinny triples, we’ve eliminated the main objections to triple glazing – weight, complexity, and cost. It’s a major win for everyone involved, from IGU manufacturers to installers to homeowners.”
Forel is already committed to the next FIT Show, and with the first new line capable of manufacturing skinny triples as well as conventional units is set to be operational in the UK by the end of 2025, it’s clear that this could mark the start of a new era for triple glazing.
For IGU manufacturers interested in finding out more about how Forel’s technology can work for them, Brian and his team are ready to talk.