Richard Hall of Reynaers UK explains how glass and glazing systems made from aluminium are helping a variety of specifiers improve sustainability and performance
Sustainability is a ‘top-of-mind’ concern nowadays; it permeates all levels of society, from a micro perspective where each household recycles its waste, through to the macro view which influences local authorities’ approach to urban planning. In the UK alone, the built environment contributes to over 40 per cent of the country’s total carbon footprint. In response, the Government created its Construction 2025 strategy, which aims to lower greenhouse gas emissions in the built environment by 50 per cent by 2025. The construction industry is responding to the challenge, as a 2018 report showed that nearly two thirds of businesses operating in this sector are more committed to taking action on sustainability than they were in 2017. With heating being one of the largest contributors to energy consumption in any household, it is natural for developers to invest in finding the sources of heat waste and develop solutions to improve a building’s energy retention. Studies from the European Aluminium Association show that 40 per cent of household heating is lost through windows or gaps around windows, which further supports the glass and glazing industry’s efforts in innovating with materials and high-performance window design.
Why aluminium is truly ‘green’
Although there are a number of materials, which claim to be environmentally friendly, aluminium is one of the few that is truly green. Firstly, it is incredibly durable, which means that regardless of the context in which it is being used, it can last for long periods of time with little or no maintenance. The top of the Empire State Building is a great example of the material’s longevity; one of the first structures to use anodised aluminium, it is still an impressive feature nearly 90 years after its construction. Aluminium is also 100 per cent recyclable. Unlike many of its counterparts, it can be recycled repeatedly without losing any of its properties. The act of recycling only requires 5 per cent of the energy needed to produce new aluminium, making it even more environmentally friendly. The building industry is taking advantage of aluminium’s unique features more and more. Currently, 35 per cent of recycled aluminium is in use and the percentage will continue to rise as older buildings are refurbished or replaced and the aluminium in their structures goes back into the supply chain. The recycling rates for aluminium reported by the European construction industry are encouraging, standing at an impressive 95 per cent. The 2003 demolition of the old Wembley Stadium is a great showcase for aluminium’s green quality, as nearly 86 per cent of the massive 213 tonnes of aluminium found in its structure was either recycled or reclaimed.
Improving sustainability with glass
Glass and glazing systems have come a long way in recent years based on innovations in both technology and design. Energy efficiency is one of the main end goals when it comes to sustainability and it can be achieved in a number of different ways. It goes without saying that great insulation is key for any window, sliding door or curtain wall when looking for ways to minimise a building’s energy loss. Advancements in this area include thermal breaks, which are strips of rigid insulation with aluminium profiles sandwiched around them to improve thermal performance. This is an innovative way to embed insulation into the core of door and window systems, visibly improving energy saving in commercial and residential builds. Making use of daylight and finding smart ways to regulate it is another way to support sustainability in the built environment. For instance, developing slim profiles for large glass panes allows more light to come in, ultimately resulting in less energy being used for lighting and heating. Aluminium’s inherent properties make this a possibility; the material only expands by 1 mm per metre and it is incredibly strong, which allows for narrow window frames to support a large glass area. Alternatively, Brise Soleil systems have been developed to reduce heat gain within a building by deflecting sunlight, therefore reducing the need to cool a building down. The future of sustainable innovation in glass and glazing is looking highly promising, from buildings using fritted glass, metal scrims or building-integrated photovoltaics, to the development of smart glass that is able to adapt its opacity in real time based on changing weather conditions to save energy. The future of sustainable innovation in glass and glazing is looking highly promising, and as one of the most adaptable materials available, aluminium has the potential to be able to accommodate any new technique seamlessly. Whether it is adjusting the depth of the window frame to integrate various glass unit types such as triple glazing, or adapting to a unique building shape that uses metal scrims and photovoltaics to create a thermal buffer between the indoor and outdoor, aluminium will continue being a key part of making sustainability in buildings a reality in designs of the future.
Richard Hall is managing director at Reynaers UK