The four storey building partly dates back to 1842 but has undergone a number of additions and renovations and the latest, designed by architectural practice TateHindle Limited, has brought the building up to the highest modern standards for office use.

The building has a classic façade with traditional sash windows, an important and attractive feature of the building's design that could not be changed. However these single glazed windows are thermally inefficient, draughty and incapable of dealing with the high noise levels found in the City and so not suited to present day needs. A solution is found through the installation of secondary glazing. An independent internal window frame set with a cavity of 100mm ensures that the two glass panes are acoustically decoupled and noise levels are typically reduced by 45dB. Higher insulation levels are attainable if the cavity is increased or heavier glass specified. The frame also traps an insulating layer of air between the windows and, together with efficient seals that minimise air leakage, markedly reduces heat loss and improves comfort near the window.

TateHindle approached Selectaglaze, the UK's leading designer of secondary glazing systems for advice and assistance as the latter has considerable experience of working within Listed and period buildings, and also has full laboratory test reports for noise attenuation capabilities. A design was required that was not only sympathetic to the building but also achieved the standards of acoustic and thermal insulation needed. The solution was a hinged casement set with a cavity of 150mm. Twin compression seals minimise acoustic loss and very neat colour matched flush hinges and flush locks ensure that the windows are discrete and unobtrusive. Full sized hinge casements were used wherever possible but in locations with lowered ceilings a high level fixed panel was introduced to allow the casement to clear. A total of 165 windows were treated.

Founded in 1966, Royal Warrant holder Selectaglaze is a specialist in the application of secondary glazing within buildings of all styles. Products are fully tested and assessed for performance and twice yearly quality audits are conducted through the company's ISO 9001 accreditation with LPCB. An extensive range of literature and guidance notes covering acoustics, thermal performance and added security is available together with a technical advisory service and a RIBA approved CPD Seminar.