Security without sacrificing light

Banqueting House is one of those buildings that requires a bit of introduction. Designed and built between 1619–22, it has stood witness to many historical events and can be found on a busy thoroughfare, a short distance from Buckingham Palace, Westminster Abbey, Downing Street and Trafalgar Square. It was primarily used to stage State events and masques and provide private drinking space for James I. Famously, King Charles I was executed outside the building in 1649. It is the only complete surviving building from the former Whitehall Palace, much of which was developed by Henry VIII, and is managed and cared for by Historic Royal Palaces, the independent charity that also cares for the Tower of London, Hampton Court, Kensington State Apartments, Kew Palace and Hillsborough Castle. Prior to Selectaglaze's involvement in the project, blast net curtains were installed for security purposes, but there was an unintended consequence: they blocked light from pouring into the Main Hall. Selectaglaze was approached to provide a bespoke solution that not only offered protection to the large windows, but also a discreet and unobtrusive window treatment that blended in with Inigo Jones' interiors. Selectaglaze knew it had products certified to the requirement, but they had never been specified to these sizes. The Main Hall window openings were 3.6m high and 2.0m wide, a significant challenge but well within our experience. Making them blast resistant posed the real challenge. Fortunately, testing had previously been carried out on a single casement that was the largest ever to be blast tested in the UK. The successful test demonstrated that blast resistance could be achieved at this scale. With the solution established, installation began. However, installing the units provided a significant challenge, as half the openings were at upper gallery level, 10m above the main floor. The gallery could not safely bear the additional load. Working very closely with Gardner & Theobold, structural engineers Hockley & Dawson and another Royal Warrant holder, scaffolders Allen and Foxworthy, a careful method of installation was devised involving a columnar scaffolding design complete with lifting apparatus to each opening. In all, 39 units were installed.

The bigger picture

Secondary glazing is often one of the most effective and discreet solutions for security, noise and energy efficiency, but is sometimes overlooked, which is why the first installation saw blast curtains as a first port of call. This secondary glazing solution provides blast protection and noise insulation in excess of 45dB, while letting natural light into the room. It is also a completely independent and fully reversible adaptation, widely accepted by most heritage bodies. The architect had the final word:

As is the case in many museums and galleries, extra consideration needs to be given to sun damage and the protection of artworks. When requested, Selectaglaze secondary glazing can be fitted with essential UV filtering to the Thomson Specification, approved by the National Gallery, V&A and others. The result is a lighter, brighter Main Hall, where Rubens’ ceiling can once again take centre stage. Working on a similar project? Get in touch.