Are glass skyscrapers really a thing of the past?

Recent reports credit comments to Sir Stuart Lipton that glass skyscrapers are set to become a thing of the past, with their floor-to-ceiling glazing deemed energy inefficient by developers in the race to net zero. Proponents of that viewpoint argue that the familiar all-glass envelopes, with their lack of opening windows, force us to battle the elements to provide a comfortable working environment, increasing our reliance on air conditioning and driving up energy consumption. Ventilating the arguments Net zero as a goal is not only mandated by government targets but, given that we are facing a climate change emergency that has been described as the greatest threat to our generation, many would argue that it is a factual necessity. The built environment is a significant and intrinsically important part of this journey as it alone accounts for at least 40% of total carbon emissions. Based on the comments of Lipton and others, you may be forgiven for thinking the reduction in glass in buildings sounds like the silver bullet for achieving net zero. However, diving a little deeper you find, as with many such conversations, the reality both environmentally and commercially is far more complex. A simple reduction in glazing should not therefore be viewed as the panacea without consequences that LED lights once were for EPC ratings. Retaining the status quo, however, is not an option. Changes to the design, construction and choice of materials used in buildings to address the climate emergency are inevitable, and necessary. We have already seen the introduction of legislation to try to address the energy efficiency of existing buildings through the Minimum Energy Efficiency Standard. Rigorous requirements for improved energy performance certificate ratings, accompanied by the penalty of prohibitions on lettings, will see most structures requiring refurbishment or redevelopment to achieve necessary ratings by the 2027 and 2030 deadlines. In finding the solutions for new buildings, those of us who make our living from the development, sale or letting of the built environment will hope that a holistic approach is taken. Ideally, this should mean that instead of simply being beaten with the stick that is MEES, we can preserve buildings as a viable and occupiable commodity for the benefit of the economy as a whole. Glass, were it merely an aesthetic choice for the exterior envelope of buildings, could be phased out willingly or through planning policy to ensure a brighter environmental future. Yet the fundamental issue is that glass is no more the sole contributor to climate change than removing it is the cure-all. Indeed, concrete, steel and aluminium are together responsible for 23% of total global emissions, and despite recent comments by the Environment Audit Committee about its carbon storage potential, turning to timber as an alternative material for construction has its own issues, especially given the height constraint on timber buildings. Through the looking glass Glass facades are not just an aesthetic choice, but a fundamental contributor to our use and enjoyment of buildings. Global research into biophilic design shows that natural light is top of the list for the most-wanted element within the workplace. Beyond that, the same research has shown that biophilic design led by the inclusion of natural light, and the availability of a view, results in improved employee performance, creativity, happiness and productivity, which explains the attraction to employers and therefore tenants of buildings that have glass facades. Light and views facilitated through glass facias are therefore essential to the modern office to preserve a developer’s bottom line and contribute to the survival of our cities and, unfortunately, many of our pensions. Flippantly, you might say that we came out of caves millennia ago and have no desire to return to windowless “caves” for work, no matter how energy efficient they may be. We all know that glass buildings can pose challenges when it comes to cooling, relying in most circumstances on air conditioning. In light of the fact that the amount of energy used for cooling has more than doubled since 2000 and is expected to double again by 2040, this is clearly unsustainable. However, glass also has benefits which are not easily replicated in high-rise structures. It is lightweight, highly workable, a natural insulator and recyclable.  Windows for tomorrow So what is the answer? The problem with cooling cannot be solved by just turning off the air conditioning any more than it should be solved by outlawing glass. The answer is that we need to embrace the complexity of the issue. There is no single solution. Detailed analysis is required for each project, alongside improvements in the technology. The glass skyscrapers of the past should certainly not be replicated. We need to build the glass skyscrapers of tomorrow. These may have less glass than those of today, but, by virtue of design changes, life cycle improvements and material selection, could allow us to benefit from the very human need for light while ensuring that we address the climate change impact of these structures. Vikki McKay is a partner at Proskauer Image © jplenio/Pixabay