Expanded cork proves its performance on a facade in Scandinavian climate

Project Eld & Bark

Expanded cork proves its performance on a facade in Scandinavian climate

Application in the Eld & Bark project in Sweden demonstrates thermal resistance, durability, and stability under extreme conditions Case Studies

The use of expanded cork as an exterior cladding in the Eld & Bark project by ELITHUS, located in Strömma in the Stockholm region of Sweden, demonstrates the potential of this natural material to withstand particularly harsh weather conditions.

Characterized by a wide annual temperature range, with temperatures ranging from below -10 °C in winter to around 25 °C in summer, this region places high demands on the materials used in building facades. Added to these factors are frequent freeze-thaw cycles, snow, and high humidity levels, creating an environment that is particularly challenging for the durability and stability of building systems.

In this context, the use of expanded cork demonstrates its ability to ensure consistent thermal performance, water resistance, and dimensional stability over time, even under extreme temperature fluctuations.

In the Eld & Bark project, the façade combines cork with wood crafted using a blend of traditional and contemporary techniques. The wooden planks were produced in four different widths, based on a custom design, and charred on-site using the traditional Japanese shou sugi ban (or yakisugi) method—an ancient technique that increases the wood’s durability and gives the architecture an aesthetic characterized by natural tones and texture

The decision to use cork as a facade cladding is directly linked to the project’s conceptual approach. According to architect Maria Ader:

"I always spend a lot of time studying the sites we are about to develop before I start drawing. One thing I’ve realized is that, as an architect, I will never be able to create anything as beautiful as the untouched nature that already exists. In this project, therefore, I wanted the houses to blend into the surrounding environment rather than stand out from it.
My intention was to work with materials as natural as possible, materials that were in harmony with the somber and rugged character of the Stockholm archipelago.
I found my inspiration in the twisted trunks of pine trees and the texture of their bark, and that idea eventually led me to cork. It is a material that has fascinated me since my studies, both for its remarkable properties and its organic beauty. Just as in nature, the shapes of the houses are asymmetrical and non-repetitive—this quality extends to the cork and the charred wood cladding that complements it."

In addition to its aesthetic appeal and structural integrity, the project also underscores a commitment to sustainability. The use of cork on approximately half of the total facade area is estimated to save the equivalent of about 80 Swedish spruce trees, since cork is harvested without the need to cut down trees and regenerates naturally over time.

From a technical standpoint, cork truly stands out for its performance. Thanks to its unique cellular structure, it offers low thermal conductivity, high insulating capacity, and natural resistance to moisture and aging. These characteristics make it particularly well-suited for facade applications in cold climates, where protection against heat loss and water infiltration is critical.

As a result, expanded cork contributes to low-maintenance, long-lasting solutions, maintaining its performance over time without the need for additional treatments. Its use in the Eld & Bark project thus reinforces the role of expanded cork as a robust technical solution for exterior environments, capable of meeting the challenges posed by different geographical locations and climatic conditions.