Harnessing the Benefits of Terra Cotta to Face Sustainability Challenges
Sustainability is an ongoing topic in the architectural industry — lowering the carbon footprint of a building is a huge, but necessary, challenge to take on. One available option: we can look to architectural terra cotta as a geologically sourced material that may help us lower our impact on the environment.
Architects have returned to terra cotta in recent decades, recognizing the greater need for circular materials that maximize efficiency and reduce waste during construction and in building performance. Terra cotta is naturally suited for sustainable façade solutions both in its economical means of production, and its inherent benefits as a building product.
Efficient Production
Boston Valley Terra Cotta is continuously enhancing our processes with sustainability in mind to further innovation in the manufacture of ceramics. Through our Design & Fabrication team, and our Architectural Ceramic Assemblies Workshop, we strive to develop new products and alternative techniques centered around terra cotta’s sustainable properties. Past ACAWorkshop cohorts have researched and built façade assembly prototypes that use terra cotta to reduce the weight of the building envelope, decrease solar absorption, and shed rainwater for capture and reuse. Our ceramic artists have also explored means of incorporating recycled materials such as glass into glazes, and how those techniques could be scaled for architectural applications.
Even before we started organizing ACAW in 2016, Boston Valley’s commitment to refining our processes has remained true. As a result, we are dedicated to improving efficiency and reducing environmental impact in the fabrication of our terra cotta products.
Recyclable Materials
Our goal at Boston Valley is to maximize re-use of materials in the manufacturing process, progressing towards a closed-loop system that extends the product lifecycle. For example, the clay grog used to make our terra cotta is comprised of up to 30% recycled material. Boston Valley’s TerraClad® panels are by design a 100% recyclable product with multiple re-use options, ranging from earth fill to integration back into clay recipes. Damaged or broken through-body units can be easily recycled into the production of new clay bodies, keeping discarded construction materials out of landfills.
Yale University’s Stoeckel Hall was recognized as one of the “Most Intriguing Green Buildings for 2010” by the Connecticut Green Building Council. The building restoration reused 87% of the original façade and structural materials.
Thermal & Energy Efficient
Despite its light weight, terra cotta has a high thermal mass and acts as an excellent insulator. Façades built with terra cotta absorb heat during the day and slowly release it at night, which is not as draining on a building’s HVAC system — lowering energy consumption and operational costs. This type of passive cooling strategy helps prevent solar heat gain, to keep the surface temperature cooler without expending more energy.
Incorporating terra cotta into the design can also offset the impact of using carbon intensive alternate materials, to some degree. And with unlimited glaze and finish options available, terra cotta can be fabricated to compliment façade components of any aesthetic.
This façade prototype by Behnisch Architekten (ACAW 2024) addresses thermal comfort through evaporative cooling. The terra cotta panels are designed to spread rainwater over the surface and direct it downward for collection.
At ACAW 2024, Make Architects explored a modular system of unglazed terra cotta that has scalable potential to mitigate climate extremes, with ways to capture, direct, retain and treat water for reuse.
Lower Energy Production
When compared to other materials commonly used in construction such as concrete, stone, or metals, terra cotta is found to carry a relatively low embodied energy. This means that the material requires less energy to manufacture than, for instance, stone — which entails high mining costs and refinement processing that puts a strain on the surrounding ecosystem. Terra cotta is a naturally derived, lightweight and abundant resource, making it easier and more efficient to transport and produce.
When discussing construction, one way to reduce the carbon footprint of a building can be through the choice of materials and where they are coming from. All Boston Valley Terra Cotta products are manufactured in the USA — we source raw materials domestically and locally wherever possible to reduce the carbon footprint associated with transportation. To track due diligence, we perform thorough supplier interviews to ensure responsible sourcing throughout our supply chain.
For ACAW 2024, Arup created a panel system with insulated core that reduces the typical carbon consumption of a façade by 24% when compared to brick, and 40% less compared to a standard terra cotta rainscreen.
Low Maintenance, Low Waste
A terra cotta façade requires little to no maintenance. Boston Valley’s TerraClad® rainscreen panel system creates a ventilated cavity that prevents the elements from reaching the structural wall, which allows air circulation to help mitigate mold and mildew growth. Glazed and through-body surfaces will also not change in color over time from UV-exposure or weathering.
Our TerraClad® installation system contributes to sustainable façade design as well. A mortarless assembly on an aluminum frame offers the durability of masonry without the weight, with no need for re-pointing. Individual terra cotta panels can be replaced when they are damaged, instead of removing the entire stacked bond. This eliminates an unnecessary waste of material and serves to reduce associated maintenance costs.
The Sustainability Challenge
With so many eco-friendly benefits inherent to terra cotta, possibilities for its use in sustainable design are vast. From material sourcing to the manufacture, construction, and operation of our buildings, architectural terra cotta can be a net positive on human impact in the midst of widespread global climate challenges. All that is required is the next innovative design to make it happen.
LMN Architects designed a modular partition wall using terra cotta for ACAW 2020. The individual modules act as vessels for water, plant life, or small animal habitats.
