Thermoseal Group’s sales director, Mark Hickox, explains why the Thermobar Interbar system is a smart choice for delivering heritage-style glazing with cutting-edge energy efficiency.

In today’s market, I see more customers asking: how can we maintain the traditional appearance of divided panes without compromising thermal performance?

That’s where our Thermobar Interbar system comes in. It’s designed to simulate the look of multiple individual panes in an IGU while working seamlessly with warm edge spacer technology – delivering not just heritage appeal, but also real-world energy savings and long-term unit stability.

Thermal efficiency has never been more important. Whether you’re fabricating for new-builds, renovations or period properties, you’re under pressure to hit ever-lower U-values and meet tightening Building Regulations.

We developed Thermobar Interbar to address exactly that – allowing fabricators to use our A-rated Thermobar warm edge spacers alongside a thermally efficient interbar solution that doesn’t introduce a cold bridge.

Unlike traditional aluminium interbars, Thermobar Interbar is manufactured from a rigid PVC-U profile with a specially developed low conductivity material that complements our Thermobar spacers. This means you get a consistent warm edge performance across the unit – essential when targeting whole window U-values of 1.2 W/m²K or below.

From a production standpoint, ease of fabrication also matters. Our Interbar slots securely into a bespoke mounting plate, which adheres to the internal surface of the unit’s spacer bar. This ensures a clean, consistent finish and simplifies the assembly process – especially useful for high-throughput IGU manufacturing.

We supply the system in a range of colours to match our Thermobar spacer bars, so you don’t have to compromise on looks either. Combined with bespoke finishing clips to cap off the joints, it delivers a smart, symmetrical aesthetic across multiple bars in the unit – something that’s particularly popular with premium and architectural glazing projects.

Of course, performance is more than just thermal values.

Every component in our Thermobar Interbar system is manufactured in-house and tested in our dedicated EN1279 laboratory for durability, gas retention and adhesion. That includes long-term testing to ensure the interbar doesn’t compromise the unit seal or increase the risk of moisture ingress.

And while we’ve focused heavily on energy performance, I think it’s the flexibility that really sets this system apart.

Whether you’re supplying traditional cottage-style windows, Georgian bars, or contemporary designs with feature grids, Thermobar Interbar adapts to the brief – helping you deliver on both compliance and customer expectations.

In short, it’s a system that lets you achieve heritage charm without sacrificing thermal efficiency – and gives IGU manufacturers a streamlined, thermally sound way to meet today’s building standards.