Glass has been indispensable in advancing contemporary human civilization: in architecture, transport, tableware and packaging. It impacts on cutting-edge sectors: energy, biomedicine, agriculture, information & communication, electronics, aerospace, optics & optoelectronics [i]. Some suggest that we live in The Glass Age[ii] and new glass products are regularly developed to address global challenges[iii], contributing to the United Nations’ Sustainable Development Goals.
Cover Image: The Four Towers, Madrid, Spain
History has many milestones where glass changed life forever. Archaeological finds and historical texts identify glass as an object of luxury, with an important social role in burials and widespread use in jewellery. Ancient writers equated the glassblower’s breath with the wisdom of the philosopher Seneca.
Glass blowing, discovered two millennia ago, opened fresh possibilities. Clear vessels stimulated storage, trade and transport. The introduction of moulds facilitated shape control; artisans could make larger, more intricate objects that were collectable, traded and given as diplomatic gifts.
The last millennium has swelled the role of glass in our shared heritage: stained glass windows have flooded the interior of sacred spaces with light, highly decorated goblets have celebrated the reign of various dynasties, and mosque lamps have communicated a patron’s generosity. Now glass dominates our architectural skyline, solar panels and glass fibre reinforced wind turbines support the energy market, while in the art world it has transcended its classification as a craft material, becoming integrated into the fine arts.
These were the arguments that built our case for a United Nations International Year of Glass 2022 (IYoG2022) to celebrate its history, current status and future. The International Commission on Glass (ICG), with the Community of Glass Associations (CGA) and ICOM-Glass broadcast a worldwide presentation of this project in 2020. Support poured in from 1500 Universities and research centres, societies and associations, museums, artists, educators, manufacturers and companies in 80 countries on five continents. Having navigated the disruption caused by a pandemic, the Spanish Ambassador negotiated a draft Resolution outlining our ambitions and steered it through various diplomatic procedures before its formal approval at the UN General Assembly on May 18th, 2021 with 19 countries as co-sponsors[iv].
Glass in architecture
Cities are hubs for ideas, commerce, culture, science, productivity, social development and much more. With populations projected to reach five billion by 2030, efficient planning and management practices are vital. Common issues are congestion, insufficient funds for basic services, a shortage of adequate housing, ageing infrastructure and rising air pollution.
The glass and glazing industry offers many solutions. Coated panes and glazing units reduce heating and cooling requirements. Advances will create buildings that are energy neutral or even contribute to the energy grid. So, the contemporary residential and commercial architectural design incorporates more and larger window areas. Many options also offer UV protection [v] and contribute to the greening of the transport sector.
A recent TNO study quantified the energy savings and CO2 emission reduction potential from such glazing[vi] across EU Member States for both 2030 and 2050. As well as the case where all windows use high-performance glazing, it simulated the impact of various window replacement rates. The study drew on sources such as today’s European building stock and performance to define input parameters, the evolution in the energy mix, the penetration of high-performance heating and cooling equipment.
The scenarios studied showed that windows with high-performance glazing could deliver 75 MTOE of energy savings in 2030 equivalent to 30% of the buildings’ energy consumption and 67 MTOE in 2050. Corresponding CO2 emission reductions were 94 MMT and 68 MMT. The European Union’s objective is to become the first climate-neutral economy by 2050, an ambitious goal requiring drastically reduced energy consumption in buildings even if energy production is decarbonised. Switchable/electrochromic glazing, glazing-integrated photovoltaics or other novel technologies may be part of the solution.
Towards a Circular Economy
Sustainable consumption is about promoting resource and energy efficiency. Currently, natural resource usage is increasing, particularly within Eastern Asia, though associated challenges of air, water and soil pollution are being addressed. Sustainable production aims at “doing more and better with less”. Reducing resource use, degradation and pollution throughout the lifecycle promotes welfare and quality of life for all and creates access to basic services, green and decent jobs.
Glass is environmentally friendly. Made from safe, readily available raw materials such as sand, soda ash, and limestone it can be infinitely recycled. As well as using more recycled waste, the glass industry is developing highly efficient melting technologies and seeking paths to carbon-neutral manufacturing[vii].
Educating consumers on the concept of a “circular economy” and explaining how lifestyle can be maintained without damaging the planet is necessary before they will commit to the challenges of global change. Accurate information is needed through standards and labels and by engaging in sustainable public procurement.
Although often taken for granted, windows allow light into homes and offices while protecting the occupants from harsh weather outside. Today, glass is used in architecture for both its functionality and its appealing aesthetics. Newly developed products include photochromic[viii] and electrochromic[ix] materials which can adapt dynamically to sunlight levels, enhancing energy efficiency.
Vacuum insulated glazing is new and has improved energy efficiency [x]. Traditional double-pane windows have a noble gas (argon) between their panes, to reduce heat loss. Now an evacuated space reduces heat transmission further. Glass strength becomes critical with such glazing since spacers are required to maintain the plane parallel geometry of the two panes and localized stresses are generated near their contact points. The panes must be perfectly sealed to prevent air ingress.
New laminated glasses increase acoustic damping to reduce “noise pollution”. A recent patent uses a viscoelastic acoustic damping layer between the two panes [xi].
Energy-saving products, including low-emissivity double glazing in buildings, mineral wool and foam glass for insulation and continuous filament glass fibre composites for wind turbines, lighter vehicles, compensate several times over during their service life for the energy consumed in production. So, the replacement of single with insulating double-glazed windows saves 60kg CO2/year compared to 25kg CO2/m2 emissions for manufacture.
Glass protagonists in architectural design
From Philip Johnson (Connecticut) to Santambrogio (Milan), glass has become the go-to material. The barriers created by floors, ceilings, and walls in a home disappear, and every nook and cranny of the house is visible from elsewhere. Philip Johnson’s Glass House in New Canaan, US is legendary in the History of Architecture. A project for his graduation from Harvard University, the house started from the idea that less is more, inspired by the postulates of Mies van der Rohe (Farnsworth House). A precursor of the modern style and of the use of new materials, it represented an extreme of dematerialization in architecture.
Designers Carlo Santambrogio and Ennio Arosio of Italian glass specialists Santambrogio are determined to show the strength and versatility of the material with stunning concept houses made completely of glass. The genius of these renowned architects has combined energy-efficient glazing with glass insulation to generate transparent glasshouses.
New functionalities supporting the use of more glass in architecture include reflective facades, antireflective coatings, switchable films permitting transparency and colour control, self-cleaning, fire resistance walls and high mechanical resistance glasses. Cities are becoming safer and more and more transparent.
The UN Year of Glass in 2022 will a) underline the technological, scientific, economic, historical and artistic role of glass in our societies, b) emphasize the rich possibilities of developing technologies and their potential for meeting the challenges of a sustainable and fairer society. It will gather the multi-coloured threads of technology, social history and art through educational programs and museum exhibitions.
To maximise the benefits of the one-off opportunity that IYOG2022 brings, glass centred organisations must work together to organise, support and promote a wide range of activities limited solely by their collective imaginations. It will require networking on a local, national and international scale among universities, colleges and schools; R&D centres and industry; museums, collectors and civil society including the government, to everyone’s mutual benefit.
So, start planning now. Our website www.iyog2022.org tells more.
[i] THE AGE OF GLASS, A Cultural History of Glass in Modern and Contemporary Architecture, Stephen Eskilson , Bloomsbury Academic, Bloomsbury Publishing PLC. ( 2018 )
[ii] Morse, D.L., & Evenson, J.W. (2016). International Journal of Appied Glass Science, 7, 409.
[iii] Varshneya, A. K., & Mauro, J. (2019). Fundamentals of Inorganic Glasses (3 ed.). Elsevier
4 Resolution L84, https://undocs.org/en/A/75/L.84
[v] Arbab, M., Shelestak, L. J., & Harris, C. S. (2005). Value-Added Flat-Glass Products for the Building, Transportation Markets. www.ceramicbulletin.org.
[vi] Glass For Europe. (2018). From https://glassforeurope.com/glazing-saving-potential-2030-2050/
[vii] British Glass Manufacturers. (2016). A clear future: UK Glass manufacturing sector decarbonisation roadmap to 2050.
[viii] N. F. Borelli, N. T. Lönnroth, M. Prassas, PM The and LA Zenteno, US Patent Application 20170075049 A1 (2017)
[ix] Granqvist, G. G. (2014). Electrochromics for smart windows: Oxide-based thin films and devices. The Solid Films, 564, 1-38.
[x] Cuce, E., & Cuce, P. M. (2016). Renewable and Sustainable Energy Reviews. 54, 1345.
[xi] Payen, C. & Fournier. (2018). U.S. Patent US 9,994,001.
This article was originally published in IGS Magazine’s Summer 2021 Issue: Read the full Magazine here for more thought-leadership from those spearheading the industry
Dr. Alicia Durán obtained a degree in Physics from the National University of Córdoba in Argentina and a PhD in Physical Sciences from the UAM, developing her professional career at the Institute of Ceramics and Glass of the Spanish Research Council (CSIC). Research Professor of CSIC and the responsible of the GlaSS group (http://glass.icv.csic.es), with more than 250 publications in WOK (H index of 46), she is currently President of the International Commission on Glass (ICG). She received the Phoenix Award from the international glass industry, being named Glass Person of the Year 2019. Now she is leading the International Year of Glass 2022, approved by the GA of United Nations on May 18th 2021.
J M Parker
Dr John Parker, a Cambridge graduate, is a Professor Emeritus at the University of Sheffield where his career was devoted to research on many aspects of glass technology, teaching and student recruitment. Since retiring he is the honorary curator of the Turner Glass Museum and writes a monthly article on glass history for the magazine Glass International. For 25 years he has worked with the International Commission on Glass supporting its many activities.