Glass structures dominate the skylines of UK cities, offering excellent views, enhanced internal daylighting and visual impact. An essential part of these curtain wall facades is the area between the glazing panels – the spandrel zone. Spandrel panels are designed to conceal unsightly elements such as floor slabs, structural columns and auxiliary connections, whilst contributing to the safety and thermal efficiency of the facade and maintaining the all-important visual appeal. These have traditionally been built up on site, with separate layers and components addressing each need – from the internal fire-resistant insulation to the exterior facing. However, to reduce complexity and ensure reliable performance, pre-insulated, single-piece spandrel panels may naturally be the next generation for this section of the curtain wall.
What are the benefits of pre-insulated spandrel panels?
Applicable since December 2018, Approved Document B of the Building Regulations, under B4 External fire spread, Regulation 7 has required that external walls of ‘relevant buildings’ over 18 metres can only be constructed with materials achieving a European Class A1 or A2-s1, d0 rating in accordance with BS EN 13501-1. This includes non-vision window spandrel panels.
With traditional built-up panels, each individual panel component must be tested and certified. However, this only tests how components act in isolation, whereas a real fire situation requires the whole system to work together to prevent a fire spreading. By having a complete pre-insulated spandrel panel specified and tested as a single unit, including all its layers, specifiers can be more confident in the performance of the product as a whole. A singular component can also help with digital specification, and as BIM (Building Information Modelling) becomes a necessity for many large-scale projects, having singular elements with consistent and dependable values (such as thermal efficiency and fire performance), modelling can be quicker and more accurate.
From the experiences of contractors and installers, over torquing, screw-threading and miscut insulation are just some examples of the errors brought about when installing a traditional spandrel panel. This potentially compromises thermal efficiency, fire performance and the lifespan of the installation. Challenges on a construction site mean it is often difficult to also ensure consistent quality, especially on high-rise structures with many other operations happening simultaneously. By listening to the pain-points of on-the-ground experts, solutions can be developed to directly address the issues of assembly, and by doing so in a factory-controlled environment, many of the problems prevalent with built-up systems are prevented before products ever reach the site.
Those designing a structure and selecting its components cannot be there at every step to ensure that the final building reflects the intended design and performance. By selecting single-component, factory-engineered solutions, they can remove much of the margin for error, ensuring reliable specification and preventing errors brought about by on-site panel assembly, maintaining the integrity of the curtain wall.
Architectural beauty has evolved over the centuries but always been essential to the way we live, work and interact with one another. Modular glass spandrel panels not only help to continue the overall effect of glazed curtain wall facades, but it is also possible to choose from a range of colours and finishes to perfectly fit in or stand out.
This is especially important with remediation work, too. Retrofitting suitable spandrel panels into an existing structure is an essential safety measure to ensure that all structures, not just new developments, are safe environments to live and work in. The flexibility afforded by bespoke, modular units offers the potential to either visually rejuvenate structures, or design panels in such a way that they are indistinguishable from previous designs. The pre-manufactured nature of these panels allows building designers to still uphold excellent thermal and fire performance without compromising the aesthetic vision of the structure.
By manufacturing products off site, with complete control over how they’re assembled, it allows pre-insulated spandrel panels to be constructed with recyclable core materials. From their steel backing tray to their insulated core or their glass facing, the panel can be engineered with end of life in mind.
This modern approach to the spandrel zone promises to streamline the specification of curtain walling, reduce the risks brought by assembly and installation, and make safe and striking design a practical reality.