Moving towards a sustainable future is a global challenge that involves all disciplines working together. According to the 2021 Global Status Report for Buildings and Construction, almost 40% of carbon emissions come from the construction industry. This places a heavy responsibility on the industry, which must be open to exploring innovative strategies, technologies, and materials in order to pave the road towards a universal sustainability goal: reaching carbon neutrality by no later than 2050.
With that in mind, this article presents three specific products and systems –low-carbon glass, low-carbon concrete, and lightweight materials– that architects are applying in their projects to contribute to a low-impact architectural design.
Low-Carbon Glass
Façades account for 20% of a building’s embodied carbon footprint. Therefore, adapting them in a way that minimizes emissions can be very helpful in reducing a project's overall environmental impact. Considering the high presence of glass in facades –as well as its role in energy efficiency–, it is important to pay attention to current innovations. For example, modern technical advancements have resulted in the first low-carbon glass, ORAÉ®, which contains 64% of recycled content and has a carbon footprint of only 6.64 kg CO2 eq./m2 for a 4mm substrate, a reduction of 42% compared to Saint-Gobain clear glass in Europe.
By combining low-carbon glass with high-performance coatings, a significant reduction of greenhouse gas emissions generated during a building’s daily use can be achieved thanks to daylight intake, solar control, and thermal insulation performances of the glazings.
This pioneering initiative has already been –or will be– successfully applied in four projects: ‘Kalifornia’ in Hauts-de-Seine, France; Elsan Group ‘Le Parc Polyclinic’ in Caen, Calvados, France; ‘Carré Invalides’ rehabilitation in Paris, France; and 'Habitat 7' in Gothenburg, Sweden. The introduction of specific low-carbon glass for façades in each of these buildings represented a key step in the path towards carbon neutrality.
Although air conditioning can be an easy solution to lower temperatures, it is clearly not the most eco-friendly option. For those seeking sustainable innovations to reduce the need for cooling equipment that doesn't compromise technical or aesthetic performance, the use of solar control glass provides both daytime benefits and solar heat protection. With an exclusive coating that reduces the amount of solar heat entering the building, it cuts down on the need for active cooling strategies.
Incorporating this material in architecture and design, triple silver control glass can be applied to façades, windows, roofs, large glazed bays, and skylights.
The benefits that this type of glass offers to buildings and the environment have translated to several projects that use solar control glass as an environmentally friendly material choice. For instance, the new spaces developed at the University of Sheffield have promoted sustainable innovations through the construction of an interlocking triangle glass roof with solar control. Apart from creating a distinction between the old and new spaces, the technology applied to the roof encloses the interior façade, improving energy balance and reducing CO2 emissions.
The façade of Gothenburg's Regionens Hus uses glass solutions to allow light to pass through while also providing a solar control function. Omniturm project in Frankfurt rises as a prominent location between the Commerzbank high-rise and the main tower of the city center. Thanks to performing solar control glass, the building is able to receive daylight without compromising the interior temperature.
Low-Carbon Concrete
Concrete’s active ingredient’s production, cement, is responsible for 5% of global CO2 emissions due to its high energy demands and the high carbon content of raw materials. Considering that concrete is the most consumed material on earth after water, the need of creating low-carbon cement products is key to reducing CO2 emissions and supporting the acceleration of the construction industry’s transition to a low-carbon economy. As a response to this challenge, Saint-Gobain Chemicals division (CHRYSO & GCP) is deploying a full range of dedicated concrete admixtures and cement additives that enable low or ultra-low carbon cement and concrete manufacturing.
Building a more sustainable future, the introduction of low-carbon concrete in architectural projects reduces environmental footprint. The use of supplementary cementitious materials such as Fly Ash, Slag, Pozzolan or calcined clay allows for concrete’s carbon footprint reduction up to 50%. Saint-Gobain’s dedicated admixture solutions also enable the use of aggregates made of locally recycled concrete, reducing further the environmental footprint of concrete while meeting all specifications.
Lightweight Materials
Within the new opportunities and innovations of lightweight materials, as a new decarbonized approach, drywall, and insulation strategies aim to reduce material density. And by reducing resource waste through these low-density materials, energy consumption and carbon emissions are significantly reduced.
Lightweight façades introduce an energy-efficient approach, one with flexible and adaptable possibilities. Characterized by a rapid installation, the façade can be previously cut at the factory to then be assembled with a dry process.
This ability to adapt to diverse sites and structures means that the system can easily be integrated into different types of projects. One of them is the renovation of the Cézanne Tower, which had a double objective: increasing the living space and improving the energy efficiency of the building.
To maintain a controlled temperature after adding closed balconies as an extension of each apartment to increase the living space, the design proposed the F4 Facade as an insulation system. With a reduced thickness, the 3,000 m2 of lightweight solution changed the project’s footprint.
For both new and reused buildings, these façade solutions imply thermal, acoustic, environmental, and economic benefits. Apart from reducing the environmental impact throughout a building's whole life cycle, they provide space, time, and cost savings that certainly contribute to a net zero future.
