Heritage Sealed Units™ is an elegant 21st century solution to an age-old problem; high performance with outstanding aesthetics.

Using a high performance warm edge spacer system, Heritage Sealed Units™ are designed specially to meet the needs of the restoration and replication sectors where the overriding criterion is authenticity.

The flexible foam spacer is desiccant filled with pre-applied adhesive and multi-layer vapour barrier backing, this simplifies sealed unit manufacture yet enables slim sightlines and narrow unit cavities. The combination with hot melt secondary sealant provides excellent durability.



First & currently the only company with passes on Heritage BS EN 1279 compliancy

Neutral in appearance and blends with any frame finish for outstanding aesthetics

Available with unit cavity options of 4mm, 6mm and 8mm

Only 3mm in depth for ultra slim sightlines

Heritage Sealed Units™ offers the latest warm edge technology to replicate and even enhance original windows in traditional and historic buildings.


Superior foam insulation

Low thermal conductivity

Substantially reduced condensation



Excellent UV resistance

Extreme temperature performance

Fast dew point drop

Excellent colour stability

High desiccant content


Smooth matte surface finish

Neutral appearance

Straight line application with 90° corners




Note: Glazing of Heritage Sealed Units ™ manufactured by JCL Glass Ltd should always be carried out in accordance with the recommendations of the Glass & Glazing federation. When glazing it is important to prevent the ingress of water into any rebate as to retain the integrity of the seal.

Heritage Sealed Units™ are NOT compatible with linseed oil putties and are recommended to be glazed with the following products: Hodgsons Heritage Putty & Hodgsons Silfix U9.