Secondary glazing

Selectaglaze secondary glazing, which offers a barrier protecting against heat loss, background noise and even theft, is helping to revitalise the Grade II listed Blue Mills in Witham, Essex

Selectaglaze secondary glazing systems using low emissivity glass can reduce heat loss by more than half and achieve a U-value of around 1.9. With sealed unit glazing this is further reduced, and a figure as low as 0.8 can be achieved. Bespoke manufacture and high-performance seals ensure the tightest fit, reducing air infiltration and almost eliminating drafts.

Secondary glazing is also an efficient method of reducing background noise, helping create a more relaxed environment. Sound travels through a primary window by a vibration of the glass. Adding secondary glazing forms a cavity, which reduces resonance and provides a second barrier for the noise to travel through. A sound level reduction of 45dB is possible. The results are achieved using high-performance seals and an air gap between the windows of 100mm or more.

Selectaglaze secondary glazing creates a second barrier of protection from the inside that can prevent the most determined thief or protect the occupants from the effects of bomb blast. Securing the contents of a building is essential; be it physical high-value objects, highly sensitive data or the people within. If this is the case, secondary glazing could provide the solution.

Blue Mills in Witham

The Grade II listed Blue Mills in Witham, Essex, dates back to the 18th century. However, its history goes back considerably further. In the 11th century, it was recorded in the Domesday Book as the water mill at Benton Hall, a subsidiary manor of Blunts in Witham. By the mid-18th century, the name Machins Mill had been replaced by Blue Mills. The original 16th century cottage is attached to a Georgian house (at the front), a sequence of early Victorian extensions and a later Victorian house in 1872 (at the rear).

In recent years, the mill was used as office space for the previous owner. Today, it has been reinstated to its 18th century version, with surviving machinery used as adornments and effective monuments to pay homage to the proud history of Blue Mills. The turret clock, which was purchased by previous owner Dr Grabham in the post-milling era, is still in place and in full working order.

The current owners have lived in Blue Mills for almost 20 years and required a thermal solution, with acoustic benefits, to make their home at the mill more comfortable. The thermally inefficient primary windows across most of the house did little to retain heat. The quirks and irregularities around some of the bay windows meant that a considered approach was required.

To begin with, a technical adviser and surveyor from Selectaglaze visited the mill to measure and evaluate all the windows that required improving. Despite the property being listed, Maldon District Council confirmed that no formal listed building consent was required for the works.

A total of 22 windows have been treated thus far using a number of window styles: fixed light, vertical sliding and side-hung casements. Two windows in the wood-panelled room were treated with Selectaglaze’s heritage Series 47 hinged casement system, which was able to sit tight behind the wooden shutters, allowing their continued operation. The aluminium profiles were coloured in a woodgrain finish that matched the existing surrounds perfectly.

With the key issue being heat retention, the owners are delighted with their decision to use Selectaglaze. As the secondary glazing has proved to significantly reduced heat loss, along with high performance seals eliminating draughts, more windows are due to be treated at Blue Mills later this year.

Selectaglaze, founded in 1966 and granted a Royal Warrant in 2004, has a wealth of experience designing, manufacturing and installing discreet secondary glazing treatments for all ages and styles of buildings – making them warmer, quieter and safer environments. Selectaglaze secondary glazing is fully fabricated in-house and delivered to site by Selectaglaze installation teams.

Contact Selectaglaze for more details; literature requests, free technical advisory or to book an online RIBA approved CPD.




Tel:  01727 837271

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