Secondary Double Glazing

 Secondary glazing is supplied fully assembled and comprises of an aluminium outer frame joined to a seasoned hardwood surround, which allows for a neat, unobtrusive installation even in the most difficult situations. A range of hardwood sub-frames and scribing trims can be used to assist face fixing, reveal fixing and the coupling of units. This allows the satisfactory refurbishment of our largest primary windows. Suitable for all types of premises including grade 1 and grade 2 listed buildings, schools, colleges, hospitals, universities, hotels and commercial buildings, i.e. offices.

Ideal for historic and listed buildings.

Secondary Double Glazed DoorsSecondary Double Glazed Windows

Secondary Double Glazing installed into a listed property. Look closely because it is not easy to see it, that’s the beauty of this product, it will not spoil the original look of the windows.

Secondary Double Glazing will eliminate drafts, increase security, reduce noise from outside.

Better by Design

We have a comprehensive range of styles to suit just about every application, including Secondary Double Glazed Doors For Listed BuildingsHorizontal Sliders, Hinged Units, Fixed and Lift-Out Units, Vertical Sliders as well as Balanced Vertical Sliders and Tilt-in Balanced Vertical Sliders. We can supply frames in white, silver or brown as standard and can accommodate any R.A.L. colour upon request to suit individual requirements. We can also provide a wide range of glass types such as clear, patterned, toughened, laminated and acoustic.

Listed Property Magazine - A Glaziers Point of View
More information on our Secondary Double Glazing can be found in the following article published by ‘The Listed Property Magazine’.

Insulation Efficiency

Our range of secondary glazing is renowned for its thermal efficiency. Varying degrees of improved thermal insulation can be achieved by using such glasses as Pilkington K and Low E. If glass is thermally at risk then care must be taken to specify toughened glass. The harmful effects of ultra violet radiation can also be reduced whilst letting in solar heat. In addition specialist films can be adhered to the glass to further increase thermal insulation whilst adding to the security of the product and the premises.

Noise Reduction

Our units have been tested for sound reduction at the AIRO Acoustics Laboratory (an accredited NAMAS Testing lab, number 0483) in accordance with BS2750: part 3 and BS5821: part 3 1980 : 1984, using a purpose built sound transmission suite.

Double Glazing in Listed Buildings

Double Glazing Condensation Leaflet

About Condensation On Glass

The Listed Property Show

The Listed Property ShowCN Glass Ltd will be attending The Listed Property Show at Olympia, London on 20th & 21st February 2016.

We will be demonstrating traditional glazing techniques where you can come and have a go at face puttying glass into a frame.

Our Heritage Double Glazed Units are produced by us using Edgetech Superspacer warm edge technology and energy efficient glasses with inert gases to fill the air gap. The units will be on display, both glazed into frames and unglazed providing the opportunity to learn everything you need to know, see and feel about the products that we are proud to produce in our workshop.

Secondary Double Glazing is installed behind existing windows but no one really wants to see it so we will have a display to demonstrate just how this is done.

Refurbishment of traditional sliding sash windows is very much a balancing game with ropes and weights. This all forms part of the glazing trade workshop and we will be there to demonstrate how we do it.

Ticket offer
Attend the show for free when you register for tickets in advance go to or by calling 01795 844939.