Duplex Glazing Bar Systems

INNOVATIVE SOLUTIONS

Heritage Astragal Glazing Bar Units for Trade Installers

Precision Alignment, Seamless Aesthetics

In the context of glazing, Duplex Glazing Bar Systems refer to internal dummy spacer bar arrangements fitted within the cavity of the IGU to simulate the look of traditional divided panes with more visual depth.

Placed between the panes during manufacture, these bars align precisely with the glazing layout, creating a convincing through-glass effect while preserving the benefits of a sealed unit.

How They Work:

Internal Duplex Bars: Positioned within the sealed unit during manufacture to replicate a Georgian or multi-pane appearance with added depth.

Factory-Manufactured Only: Duplex bars are made by us inside the cavity of the IGU and cannot be fitted on site by the customer.

Alignment: Precise placement ensures the internal bars sit cleanly within the overall glazing design.

Duplex Glazing Bar System

Our Duplex glazing bar system adds visual depth and a more authentic heritage finish than standard internal Georgian bars, while retaining the practical benefits of a sealed IGU.

Available in black, white and grey, with widths of 18mm, 24mm and 36mm.

The Duplex system delivers enhanced visual depth and improved authenticity compared to standard internal Georgian bars, while benefiting from warm edge spacer technology to support thermal efficiency and condensation resistance.

Why They Matter:

Visual Continuity: Adds stronger depth than a standard internal bar layout and helps the glazing pattern read more convincingly.

Manufactured Accuracy: Because the bars sit inside the sealed unit, precise factory positioning is essential for a clean finish.

Compatibility: Well suited to heritage-led glazing projects, including timber and PVC window styles where added depth is required.

Ideal for:

Key Benefits:

Creates the illusion of individual glazed panes within a sealed unit

Supports planning acceptance in heritage and conservation settings

Enhances visual realism in Astragal bar configurations

Helps maintain consistent performance with modern IGU standards

Improved Stability on Large Units

Enhanced Perceived Strength & Security

Best For: Projects requiring authenticity, precise visual alignment, and planning compliance — especially when replicating traditional joinery with the performance of a modern sealed unit.

Astragal Glazing:

Key Benefits:

Factory-applied glazing bars offer clear advantages for installers and end clients alike. By applying astragal bars in a controlled manufacturing environment, we ensure precise alignment, secure bonding and a consistent finish across every unit. This reduces installation time on site, minimises the risk of damage or misalignment, and provides long-term durability — all backed by product warranty for added reassurance.

Built for Glaziers. Designed for Heritage Projects.

We understand that installation efficiency and finish quality are critical on heritage projects.

If you’re specifying glazing bars for an upcoming project, contact our team early in the process so we can manufacture your insulated glass units ready for installation.

With fast lead times, factory precision and product warranty for added reassurance, we help you deliver heritage aesthetics with modern performance — on time and with confidence.

By choosing factory-applied glazing bars, you benefit from:

  • Reduced installation time
  • Improved visual consistency
  • Lower snagging risk
  • Reliable long-term performance
  • Professional presentation to your client
  • Warranty

Why Should Glazing Companies Choose Crystal Units for Bar Units?

Because we make your installations faster, cleaner and more reliable.

Factory Precision, Every Time

Our glazing bar units are manufactured in a controlled factory environment, ensuring accurate alignment, consistent spacing and secure bonding. No site guesswork. No uneven sightlines.

Faster Installation on Site

Units arrive ready to fit. That means less labour time, fewer adjustments and quicker turnaround on projects.

Reduced Snagging & Call-Backs

Factory-applied bars minimise the risk of misalignment, detachment or cosmetic issues that can occur with site-fitted systems.

Wide Range of Profiles & Finishes

From Georgian and Astragal to Duplex and external stick-on bars, we offer multiple sizes and powder-coated finishes to suit heritage and contemporary requirements.

Thermal Performance Maintained

Our bar systems are integrated within high-performance insulated glass units, preserving energy efficiency while delivering the traditional multi-pane appearance.

Fast Lead Times

We understand project schedules. Our manufacturing capability allows us to offer efficient production and dependable delivery times.

Product Warranty for Peace of Mind

All factory-applied glazing bar units are covered by warranty, giving glazing companies and their clients added reassurance.