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Selectaglaze - Secondary Glazing Systems

Secondary Glazing - Energy Performance Certificate - EPC - U-values - ISO 9001

The Secondary Glazing Specialists

Founded in 1966, and Royal Warrant Holder since 2004, Selectaglaze has a wealth of experience providing bespoke secondary glazing to buildings of all styles. From Listed heritage buildings to new-build hospitals, hotels to school classrooms, museums to private homes; secondary glazing can be used to enhance their environment.


‘Measuring carbon footprint’ and ‘becoming more sustainable’ are just two of the phrases that are increasingly iterated by organisations, Government and private individuals. There is also growing awareness that a high-ranking Energy Performance Certificate (EPC) will ensure buildings meet acceptable standards for letting and enhancing market value.

One way to cut down on heat loss and keep warmth within is to create a second barrier to the elements from the inside and install secondary glazing. Purpose designed frames with thermally efficient glass can reduce heat loss by more than half and advanced seals will minimise losses through air leakage, almost eliminating draughts.

Secondary glazing can achieve U-values of around 1.9. This not only creates a more comfortable living or working environment, but also reduces energy bills.


High noise levels can be very disturbing, leading to problems with sleep, concentration and well-being. Secondary glazing provides the most effective way of cutting out unacceptable noise as the wide separation between the inner and outer glass decouples the panes to markedly reduce sound transmission.

Well-designed secondary glazing set 150mm apart from the outer window will achieve 45dB reduction compared with about 34dB for standard double-glazed units. As 10dB equates to a doubling of the sound level, this represents a significant improvement.


Improved security provides peace of mind and simple secondary glazing with locks and strengthened glass offers an unobtrusive second barrier to entry, deterring the opportunist thief. However, many buildings will need much higher levels of protection, both for people and for high value artefacts or sensitive data. In these cases, secondary glazing with certified levels of protection against determined intruders, bomb blast or even a ballistic attack are available.


Throughout the UK there is a wealth of buildings with architectural or historic interest. Historic England cites over 375,000 registered Grade I & II Listed in England alone. Many of these were built between the 16th and 19th century with very different construction materials and standards to those used today. Therefore, the buildings are generally cold, draughty, noisy and un-secured.

Most of the UK’s heritage bodies accept that secondary glazing is a reversible adaptation and, when sensitively designed, can provide real benefits that ensure the building continues in use and is well looked after.

Tried & Tested

Selectaglaze secondary glazing is rigorously assessed and tested for acoustics, thermal insulation, intruder protection, blast mitigation and ballistics. The Company is accredited to Secured by Design and has a range of ‘Police Preferred Specification’ products. Quality is extremely important and the Company is certified to ISO 9001.

Every window is bespoke built at the St Albans factory to ensure best fit and installations are completed rapidly with minimal disruption to the buildings’ occupants.

Selectaglaze offers technical advice on projects as well as assistance in selecting the right product for your specification.

Also, if you want to learn more about what secondary glazing can do for your future projects, please contact us to arrange a RIBA approved CPD seminar in “Understanding and Specifying Secondary Glazing”.

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Secondary Glazing

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Selectaglaze Product Range secondary glazing Royal Warrant Holders energy performance

Images top to bottom:
Grade II Listed St Albans Museum & Gallery;
Grade II Listed Royal College of General Practitioners (Offices);
Grade II Listed Cosway Street (Sports Centre);
Grade II Listed The Priory (Residential)

Selectaglaze Ltd
Alban Park
Hatfield Road
St Albans

Email Selectaglaze

Tel: 01727 837271
Fax: 01727 844053

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