Global Sustainable Glass Windows: Comprehensive Analysis

Written by

Inemesit Ukpanah

Last updated

26 April 2024

Energy-saving or sustainable glass windows have emerged as crucial players in sustainable architecture and construction. These windows enhance insulation, reduce energy consumption, and create a more comfortable indoor environment. 

The global insulating glass window market, a key segment of the sustainable glass industry, was valued at £9.6 billion in 2021 and is projected to reach £12.9 billion by 2026, growing at a compound annual growth rate (CAGR) of 6.1%. This growth is driven by the rising trend of energy-efficient building construction, further accelerated by government regulations for energy-efficient buildings. 

Sustainable glass windows are renowned worldwide as one of the most sustainable building materials. Made from raw sand, soda ash, and limestone, glass is 100% recyclable with no loss of quality. Moreover, insulating glass windows increase the thermal efficiency of buildings by minimising the transfer of heat/cold from within the building environment to the outside environment. 

The burgeoning demand for energy-efficient solutions in the residential and commercial sectors is breathing fresh life into the global sustainable glass windows market. 

This comprehensive guide explores the statistics, trends, and facts that shape this dynamic industry and offers a glimpse into its future.

Global Sustainable Windows Statistics

The global market for energy-efficient windows had a revenue holding of £13,548 million in 2021 and is expected to reach £27,770 million by 2030. The increasing awareness of environmental sustainability and climate change mitigation techniques primarily drives this growth. 

The windows and doors industry has grown significantly, with the global market exceeding £114 billion in 2020. The market is predicted to experience a compound annual growth rate (CAGR) of 6.2% from 2021 to 2027. 

Statistical Facts on Windows

The global statistics on sustainable windows highlight the increasing importance of energy efficiency and sustainability in the construction industry. Energy-saving windows, a crucial component of sustainable design and construction, can reduce energy use in buildings by up to 40%. 

Here are some key global statistical facts:

1. Energy-efficient windows can reduce energy use in buildings by up to 40%
2. The Global Energy-Efficient Window Market size is expected to reach £14.1 billion by 2027, growing at a market growth of 6.2% CAGR during the forecast period.
3. The global energy-efficient windows market is expected to reach £28 billion by 2030
4. The US Department of Energy reports that Energy Star-certified windows can reduce yearly energy expenditures by up to 15%.
5. Nearly 35% of residential heating and cooling energy is lost through windows, but energy-efficient windows can help reduce this loss.
6. Replacing single-pane windows with energy-efficient alternatives in a typical home can save up to 4 tons of carbon dioxide emissions annually. 
7. Energy-efficient windows can reduce a home’s heating and cooling capacity loss by 25% to 30%. This can result in significant savings on utility bills.
8. In 2023, 42% of companies in the fenestration industry planned to focus their product development on improving energy efficiency, highlighting the growing importance of sustainability in this sector.
9. The average replacement cost for energy-efficient windows with an Energy Star rating ranges from £360 to £2,370 per window, depending on various factors such as size, material, and installation costs.
10. In 2022, the most demanded fenestration products included vinyl windows (56%), wood windows (21%), and aluminium windows (19%). Energy Star-rated, typically more energy-efficient products accounted for 14% of the demand.
11. The UK window and door market is expected to grow at a CAGR of 5.3% from 2023 to surpass £3.5 billion by 2030.

The environmental benefits of energy-efficient windows cannot be overstated. According to a study by the U.S. Environmental Protection Agency (EPA), buildings account for nearly 40% of the total energy consumption in the United States. This percentage could be significantly reduced by reducing energy losses through energy-efficient windows, leading to a substantial decrease in greenhouse gas emissions.

Furthermore, the Department of Energy estimates that energy-efficient windows could save homeowners up to 30% on their annual energy bills. This helps individuals save money and reduces reliance on fossil fuels, promoting a greener and sustainable energy landscape.

Moreover, the materials used in sustainable windows are also necessary. For instance, glass, a key component of windows, is an eco-friendly, endlessly recyclable material. Other materials like aluminium, timber, and uPVC can also be recycled and repurposed, further enhancing the sustainability of these windows.

The Rise of Sustainable Windows

Stringent building codes and sustainability certifications to reduce carbon emissions drive widespread adoption of energy-efficient windows. For instance, the UK’s Future Homes Standard mandates triple glazing for new homes constructed from 2025. Similar regulations across Europe and North America propel the shift to high-performance glazing with low U-values, which measure heat loss through windows. 

Industry estimates suggest that meeting upgraded energy codes often requires upgrading from double to triple glazing. In the US, the Energy Star Most Efficient criteria for 2024 have tightened U-factor and Solar Heat Gain Coefficient (SHGC) requirements in several climate zones, making triple glazing necessary for compliance. As a result, triple glazing is forecasted to account for over 20% of the US residential market by 2030, up from 3% currently.

• Double glazing reduces heat loss by up to 60% compared to single glazing, saving around 405kg of CO2 emissions annually.
• Triple glazing is around 50% more thermally efficient than double glazing, reducing energy costs and environmental impact.
• The upfront cost of triple-glazing windows is higher, but the long-term energy savings can justify the investment, especially in extreme climates.
• Triple-glazed windows provide better noise insulation, security, and resistance to adverse weather conditions than double-glazing.
• High-quality triple glazing can reduce solar heat gain by around 20% compared to double glazing, keeping homes cooler in summer.

The result is a significant reduction in energy consumption, leading to lower utility bills and a reduced carbon footprint. 

Regarding sustainable windows, the choice of material plays a pivotal role. Aluminium, for instance, is 100% recyclable, providing high levels of sustainability. Modern uPVC, on the other hand, can be recycled and reused up to 10 times without losing quality. 

These materials contribute to environmental conservation and offer durability and longevity, making them a smart choice for homeowners and businesses. Moreover, these windows are typically made from sustainable materials like vinyl, fibreglass, or wood, which have a lower environmental impact. 

Low-emissivity (LOW-E) coatings on glass control heat transfer within the insulated glazing, reducing energy loss by 30% to 50%. Windows manufactured with Low-E coatings typically cost 10% to 15% more than regular windows but offer significant energy savings. 

Another innovation in the sustainable glass window market is the use of vacuum-insulating glass windows, which offer increased potential for energy efficiency. These windows are gaining popularity due to their superior thermal performance and potential for reducing energy consumption in buildings. 

Window Product Trends

In 2022, the most demanded fenestration products were vinyl windows (56%), multislide/multi-panel patio doors (22%), and wood windows (21%). However, the industry is shifting towards more sustainable and energy-efficient solutions. 

For instance, low-emissivity (Low-E) glass, which minimises the amount of infrared and ultraviolet light passing through, is rising. This innovation reduces energy costs by returning heat to its source, ensuring interiors remain cool in summer and warm in winter.

Smart glass is another trend gaining momentum. This technology controls the light and heat passing through the glass, contributing to energy efficiency and comfort. Furthermore, the industry is seeing a rise in the use of large sliding or foldable glass doors, minimalistic glass railings, and skylights, allowing for an uninterrupted view and a sense of unity with nature.

Photovoltaic Glass turns Windows into Energy Generators

Building-integrated photovoltaics (BIPV) through solar glass facades and windows transform buildings into renewable energy generators while reducing electricity costs. Advancements in organic PV technology have enabled the production of highly transparent solar windows that can generate electricity from interior light.

Startups such as Ubiquitous Energy and SolarWindow commercialise transparent solar glass products with potential applications in skyscrapers, greenhouses, automobiles and consumer devices. The global BIPV glass market is estimated to reach £5.4 billion by 2028, driven by green building initiatives and zero-energy construction.

Sustainability and Energy-Efficiency Windows

Glass is renowned as one of the most sustainable building materials available. It is made from raw sand, soda ash, and limestone and is 100% recyclable with no loss of quality. 

The industry is making strides in crafting energy-efficient solutions, focusing on reducing energy use in existing and new buildings. For instance, replacing all existing windows with high-performance glazing by 2030 could cut annual energy use by 29% and yearly carbon emissions by 28%.

Automation and Digitalisation Improve Efficiency and Productivity

The integration of Industry 4.0 solutions is optimising glass manufacturing, coating, and fabrication processes. Automated robotic technologies enhance speed, precision, quality, and consistency in glass product manufacturing. Digital tools like virtual and augmented reality are also gaining traction in design, training, and maintenance procedures.

Digital glass technologies enable smart functionality in windows for natural light optimisation, noise control, privacy, temperature regulation, and air purification. Adopting connected glass hardware, software, and IoT-based systems will be critical to creating intelligent buildings and cities.

Regional Analysis of the Sustainable Glass Windows Market

The sustainable glass windows market, which includes energy-efficient and insulating glass windows, is experiencing significant growth globally. This growth is driven by increasing environmental awareness, the need for energy efficiency, and the rising trend of sustainable building construction.

Global Market Overview

The global insulating glass window market size was worth approximately £9,416.09 million in 2021 and is expected to reach about £16,764.32 million by 2030, growing at a CAGR of 6.9%. The global energy-efficient windows market was valued at approximately £12.3 billion in 2022 and is projected to grow to about £26 billion by 2032 at a Compound Annual Growth Rate (CAGR) of 7.8%. The market is expected to reach about £13.8 billion by 2026.

Energy-efficient windows are designed to form a barrier that prevents heat and air movement to the exterior, reducing the cost of air conditioning. The primary components of an energy-efficient window are the window frame, glass that may or may not contain specialised coatings, such as low emissivity (Low-E) coating, and additional hardware.

The global insulating glass window market was valued at approximately £10,139.36 million in 2021 and is projected to reach about £13,662.24 million by 2026. Insulating glass windows increase the thermal efficiency of buildings by minimising the transfer of heat/cold from within the building environment to the outside environment.

The energy efficiency of a window is evaluated using two primary metrics: the solar heat gain coefficient (SHGC), which measures how much solar heat enters through the window, and the U-factor, which measures the window’s insulating ability. 

Regional Trend and Analysis

Europe

Europe is another significant market for energy-efficient glass, with enormous consumption registered in the United Kingdom, Germany, France, and other countries.

In Europe, the production of glass was affected by the COVID-19 pandemic, with a decrease of 2.6% in 2020 compared to 2019. However, the insulating glass window market is mainly driven by the rising trend of energy-efficient building construction.

As of today, the European doors and windows market, which includes sustainable glass windows, is projected to reach GBP 61.86 billion by 2028, growing at a CAGR of 4.13%. The increasing demand for energy-efficient solutions and sustainable practices drives this growth. For instance, Europe’s acoustic insulation glass windows market is expected to experience a significant increase between 2023 and 2030.

The European region has several notable manufacturers with a significant regional presence, including Deceuninck Group, VKR Holdings A/S, and Rehau. In addition, bonded windows have created quite some excitement within the windows industry over the past two years. 

In the UK, Clayton Glass has introduced EcoMAX Glass™, an eco-friendly glass window unit produced from the highest level of recycled materials at one of their efficient UK glass plants. This unit is almost 100% biodegradable and performs perfectly with typical A and A+-rated windows.

Furthermore, households replacing their windows with energy-efficient products could save up to £155 a year. Even properties that have C-rated double-glazed windows fitted could be saved based on the housing style. Below is the cost estimate of the amount of savings based on each house model:

A set of A-rated windows for a semi-detached house will typically cost around £15,000.

Over a more extended period, these savings can be substantial. For example, replacing the windows in a mid-terrace house with long-lasting, durable uPVC double glazing marked with an A-rating could save up to £425 over five years or £850 over ten years.

Comparative Analysis of Double and Triple Glazing

North America

In North America, the market for insulating glass windows is expanding due to falling energy and air conditioning costs, rising sustainability awareness, and increasing energy demand. Manufacturers in this region offer a wide selection of insulating glass windows and service & sales support, which helps the market expand.

The North American doors and windows market is expected to reach GBP 67.34 billion by 2028, growing at a CAGR of 4.56%. This growth is driven by the focus on developing energy-efficient buildings and integrating high-efficiency doors and windows to improve thermal efficiency and save energy costs.

In the United States, the adoption of energy-efficient windows is driven by the need to reduce energy costs. The US Department of Energy reports that Energy Star-certified windows can reduce yearly energy expenditures by up to 15% (approximately £54 to £79), depending on the window type and where it is installed.

The market for energy-efficient windows is dominated by North American manufacturers, including Andersen Corporation, Jeld-Wen Holding, Inc., Marvin, Masco Corporation, PGT Innovation, Inc., and Cornerstone Building Brands.

Asia

The Glass Window Wall Market is set to experience steady growth, driven by continuous technological advancements, growing environmental awareness, and the rising need for streamlined operations.

The Asia Pacific intelligent glass market, a vital segment of the sustainable glass windows market, is estimated to grow at a CAGR of 14% in the forecasted period (2021-2026). This growth is attributed to the surging demand for energy cost savings in high-end commercial offices and residential spaces. 

Furthermore, the Asia Pacific construction glass market is expected to grow significantly due to rapid industrialisation and an upsurge in construction activities in developing economies such as China and India. 

Middle East and Africa

The switchable smart glass market in the Middle East will grow substantially in the coming years. Technological advancements and increasing demand for sustainable solutions will fuel the market’s growth. 

The Middle East and Africa flat glass market, a vital segment of the sustainable glass windows market, is expected to grow at a CAGR of 6.9% between 2023 and 2029, reaching a value of GBP 18.9 billion by 2029.

This growth is driven by increasing investments in renewable energy, particularly solar power panels, and favourable government policies promoting sustainable development, energy efficiency, and infrastructure developments.

Here is a table for a quick overview of the market size between 2026 – 2030

Market Trends and Growth Opportunities

The sustainable glass windows market is witnessing several trends and growth opportunities. The rising trend of energy-efficient building construction mainly drives the market. There is also a growing emphasis on sustainability-promoting regulations and rapid urbanisation and construction activities worldwide.

Emerging trends and innovations in the Glass Window Wall market include continuous technological advancements, growing environmental awareness, and the rising need for streamlined operations. To seize the evolving market opportunities, industry players are anticipated to concentrate on product innovation, strategic collaborations, and geographical expansion.

Factors Influencing Market Growth

Several factors influence the growth of the sustainable glass windows market. These include:

1. Government Incentives: Governments across the globe are promoting the use of energy-efficient windows through various incentives. For instance, the Environmental Defense of Canada rewards customers who install new Energy Star-certified windows with a reward of approximately £394 per window, up to a maximum of around £3,937.
2. Energy Savings: Energy-efficient windows can significantly reduce energy consumption and costs. According to the US Department of Energy, Energy Star-certified windows can reduce annual energy expenses by up to 15%, which translates to savings of approximately £56 to £83, depending on the window type and its installation location.
3. Technological Advancements: The advent of low-emissivity (Low-E) glass, vacuum-insulated glazing, and recycled materials has revolutionised the energy-saving windows industry—additionally, smart technologies like electrochromic and thermochromic glass offer impressive energy-efficiency features.
4. Increasing Demand for Sustainable Solutions: The escalating awareness of climate change and the need for energy-efficient solutions in residential and commercial buildings drive the demand for sustainable glass windows.
5. Environmental Awareness: The growing consciousness about the environmental impact of energy consumption is fueling the demand for energy-efficient products.

Waste Reduction and Recycling of Windows

The global waste crisis is a pressing issue, and the glass industry plays a significant role in this narrative. This article explores the recyclability of glass windows and the potential for circular economy practices in the glass industry.

The Recyclability of Glass Windows

Glass is 100% recyclable and can be recycled endlessly without loss in quality or purity. However, recycling glass windows presents unique challenges due to the presence of additives like metal oxides and salts, which can affect the colour and melting temperature of the glass. 

When window glass is recycled, it is typically used to create fibreglass or other building materials rather than new window panes. 

Despite these challenges, technological advancements have made it possible to recycle glass windows effectively. According to WWF, it reduces related air pollution by 20% and water pollution by 50%. For instance, new processes have been developed to separate the glass from the window frame and other components, enabling the recycling of the glass and the frame.

Moreover, recycling glass reduces the landfill space used bottles and jars would otherwise take up. 

Impact on Waste Reduction

Recycling glass windows can significantly reduce waste. For every tonne of glass recycled, over a tonne of raw materials is saved, and the amount of waste sent to landfills is reduced by about 315 kg. Moreover, recycling glass uses 40% less energy than manufacturing new glass and reduces related air pollution by 20%.

Circular Economy Practices in the Glass Industry

The circular economy concept is gaining traction in the glass industry. This consists of three essential steps: reduce, reuse, and recycle. In the case of glass, reducing non-renewable materials lowers the environmental impact. The glass packaging industry supports a “zero waste” policy, higher recycling targets, and separate collection to transition to a circular economy.

This model involves designing products and systems to minimise waste and make the most of resources, which aligns well with the principles of glass recycling.

Several initiatives are underway to promote circular economy practices in the glass industry. For example, the Glass Recycling Coalition (GRC) works to improve glass recycling through education, best practices, and industry collaboration. Similarly, the European Container Glass Federation (FEVE) has launched the “Close the Glass Loop” initiative to achieve a 90% glass collection rate for recycling by 2030.

The circular economy model can also have a positive economic impact. According to the Ellen MacArthur Foundation, transitioning to a circular economy could generate a net economic benefit of £1.8 trillion for Europe by 2030.

Future of Sustainable Glass Windows

Sustainable glass windows are poised to transform the architecture and construction industry, offering energy efficiency, environmental conservation, and aesthetic appeal. The predicted trends and innovations discussed so far demonstrate the vast potential of sustainable glass windows in reducing energy consumption, harnessing solar energy, and minimising environmental impact.

For instance, around 23% of the UK’s current housing stock has double glazing installed pre-2002, which is 50% less energy efficient than new windows meeting current standards.

As the demand for sustainable buildings continues to rise, the development and widespread adoption of these technologies will play a crucial role in creating a greener and more sustainable future.

Adopting sustainable glass windows can significantly contribute to reducing energy consumption and moving towards a sustainable future. Energy-efficient windows minimise energy loss, resulting in reduced heating and cooling costs. Buildings account for an estimated 40% of global carbon emissions, with building operations producing 27% of total emissions. The industry can help reduce carbon emissions and promote environmental conservation by incorporating sustainable glass windows.

Predicted Trends and Innovations

As the demand for sustainable building practices and energy-efficient solutions grows, the glass window industry is expected to evolve and adapt to these needs. Here are some key invitations to watch out for:

1. Smart glass technology: Smart glass, also known as switchable glass, can change its light transmission properties when an electric current or other stimulus is applied. This technology significantly benefits energy efficiency, privacy, aesthetics, and comfort. Buildings equipped with smart glass technologies can save up to 20% on cooling expenses and 35% on lighting costs.

In addition, when exposed to sunlight, the glass darkens to reduce glare and heat gain, thus reducing the need for artificial cooling systems. Smart glass can also be controlled manually or integrated with building automation systems to optimise energy consumption. The global smart glass market is projected to reach £7.8 billion by 2026, indicating significant growth and adoption of this technology.

2. Dynamic glass: Windows using dynamic glass technologies can save up to 10% on total building energy costs. This technology allows for dynamic control over the transparency, thermal insulation, and glare reduction of glass surfaces.

3. Energy-efficient coatings: One of the key trends in sustainable glass windows is the development of energy-efficient coatings. These coatings are designed to reduce the transfer of heat through the glass, thereby improving the thermal performance of buildings. One such innovation is the low-emissivity (Low-E) coating, which reflects heat into the room during winter while allowing solar heat to penetrate during summer. This technology significantly reduces the need for heating and cooling, leading to substantial energy savings. According to a UK Energy Saving Trust study, Low-E coatings can save up to £70 per year in heating costs for an average-sized home.

4. Improved thermal insulation glazing: Innovations include novel low-E coatings, gas-filling, warm-edge, aerogel-filled, and vacuum glazing. These advancements improve the thermal insulation properties of windows, reducing energy consumption and greenhouse gas emissions.

5. Adaptable (Chromogenic, Switchable) glazing: These technologies allow windows to change their properties in response to external stimuli, such as light or heat. This can help regulate the light and heat entering a building, improving energy efficiency and occupant comfort.

6. Integration of photovoltaic: Integrating photovoltaic technology into glass windows can help generate clean, renewable energy for buildings. These windows incorporate thin-film solar cells or organic photovoltaic materials to harness solar energy. The generated electricity can power various building functions or be fed into the grid. With advancements in solar cell efficiency and manufacturing techniques, solar windows are becoming more viable and cost-effective. A research study by the University of Oxford estimated that solar windows could generate up to 20% of a building’s energy needs.

These advancements promise to make our buildings more energy-efficient, comfortable, and environmentally friendly, contributing to a more sustainable future.