In this blog post, we’ll take a comprehensive look at the structure and operating principles of double-skin facades, their advantages and limitations, and the challenges of adopting them in Korea.

Overview of Double-Skin Facades

The term “green architecture” generally refers to architecture that minimizes impact on the natural environment while maximizing the use of external natural conditions and natural energy, and actively utilizing renewable energy sources. To reduce energy consumption in buildings, it is crucial to improve the performance of the building envelope—the most vulnerable part where heat loss occurs. Among the eco-friendly envelope systems developed for this purpose, the double-skin facade is the most widely adopted and technically validated method.
Also known as “Double Facade,” “Double Skin,” or “Twin Facade,” the double-skin structure is a state-of-the-art building envelope system that satisfies both functional and aesthetic requirements. There are examples that emphasize unique exteriors, such as the Quartier des Spectacles in Montreal, Canada, and the Torre Glòries (formerly Torre Agbar) in Barcelona, Spain, as well as a wide variety of applications designed to maximize energy savings and natural ventilation performance.

Structure and Basic Components

A double-skin facade is a multi-layer structure that adds an additional skin to the exterior of an existing facade. It generally consists of an outer envelope exposed to the outside air, an inner envelope facing the interior, and a cavity formed between the two envelopes. Horizontal blinds or shading devices are installed in the cavity, and ventilation openings are provided at the top and bottom to control airflow.
The outer envelope serves as the primary barrier, protecting the interior from external weather conditions and noise. By designing appropriate ventilation openings at the top and bottom of the outer envelope, high external wind pressure can be mitigated, dispersed, and directed into the cavity, thereby enabling natural ventilation even in high-rise buildings.

Seasonal Operating Principles and the Chimney Effect

Double-skin facades typically use transparent glass—which facilitates heat transfer—for both the inner and outer skins, but the air layer formed between the two panes serves as insulation and a thermal buffer. During winter heating, the openings in the inner and outer skins are closed so that the cavity acts as a thermal buffer space. This allows some of the heat from the cavity—warmed by solar radiation—to flow into the interior, while simultaneously reducing heat loss from the interior to lower the heating load.
Conversely, during summer cooling, the inner openings are closed and the outer openings are opened to vent the heat from the cavity to the outside. When the air in the cavity is heated by solar radiation, its density decreases, creating buoyancy that causes it to rise and escape through the upper opening. At the same time, fresh outdoor air enters through the lower opening, facilitating natural ventilation. This phenomenon is commonly known as the “chimney effect” and plays a key role in reducing the cooling load by enhancing the ventilation performance of the cavity.
Furthermore, during transitional seasons such as spring and fall, actively introducing outside air reduces the operating time of mechanical heating and cooling systems, while natural ventilation helps maintain a comfortable indoor environment.

Advantages Provided by a Double-Skin Envelope

First, by utilizing the air cavity and blinds for solar shading and thermal insulation, indoor heating and cooling loads can be significantly reduced, thereby lowering the building’s energy consumption. Even when glass is used as the primary envelope material, the combination of an air layer and shading devices can effectively reduce energy loss through the envelope.
Second, even when external wind pressure and wind speed have a significant impact on high-rise buildings, the double-skin envelope mitigates fluctuations in wind pressure, providing a more stable environment for natural ventilation. As a result, natural ventilation becomes possible even at high altitudes, indoor air quality (IAQ) improves, and discomfort that can arise in environments reliant on mechanical ventilation is reduced, creating a more comfortable indoor environment.
Third, it is effective at blocking external noise. In particular, applying a double skin to high-rise buildings in urban areas that use glass curtain walls helps significantly reduce external noise and improve the indoor acoustic environment.
Fourth, securing ample natural daylight through a transparent envelope can provide psychological and physiological satisfaction to occupants, while also offering energy savings on lighting through the use of natural light. Furthermore, a glass envelope lends the building a modern and sophisticated image, enhancing its value and aesthetic quality while positively influencing a company’s brand image.
Fifth, it offers advantages not only in terms of psychological comfort but also in crime prevention and fire safety. The air cavity can serve as a space to control airflow, and when proper fire-resistant design is implemented, it helps delay the vertical spread of fire and smoke. However, actual fire safety can only be ensured by meeting relevant design standards, such as fire compartments, fire dampers, and fire resistance ratings.

Overseas Application Trends and Challenges for Adoption in Korea

While past overseas applications of double-skin facades often emphasized the aesthetic appearance of buildings, they have recently evolved into high-performance envelope systems designed to simultaneously achieve energy savings, reduce carbon emissions, and improve indoor environments. Curtain wall specialists are developing various double-skin systems that enhance energy performance, natural ventilation, and ease of maintenance, while smart envelope technologies—integrated with digital simulations and Building Energy Management Systems (BEMS)—are also continuously advancing.
In contrast, South Korea currently lacks sufficient specialized personnel and accumulated research for double-skin design, creating a need to develop design and construction technologies suited to the country’s climate characteristics and architectural environment. Since this field requires not only expertise in curtain walls but also a broad understanding of architectural environmental engineering, energy analysis, ventilation, and thermal environments, it is crucial to strengthen both design and construction capabilities.
Therefore, starting from the planning stage, various stakeholders—including academia, building owners, design firms, contractors, and curtain wall specialists—must collaborate to thoroughly review case studies from both overseas and Korea, and conduct a comprehensive analysis of life cycle costs (LCC), which includes not only initial construction costs but also maintenance costs and energy savings. Furthermore, when selecting a building envelope system, factors such as the surrounding environment, building use, sound insulation performance, potential for natural ventilation, and ease of maintenance must be comprehensively considered.
Recently, as interest in Zero Energy Buildings (ZEB) and carbon-neutral architecture has grown in Korea, research and demonstration projects on double-skin technology have been steadily expanding. Particularly in Korea, where there are many high-rise buildings, the scope of application for this envelope technology—which can simultaneously achieve energy savings, indoor comfort, and aesthetic value—is likely to expand even further in the future.

Conclusion

A double-skin structure is not merely a device to beautify a building’s exterior; it is a high-performance envelope strategy capable of comprehensively addressing various architectural environmental issues, such as thermal comfort, natural ventilation, solar shading, and noise reduction.
However, to achieve optimal performance, appropriate design that considers the building’s use and local climate, systematic operation, ongoing maintenance, and economic feasibility studies must all be carried out in tandem. If these conditions are met, the double-skin structure will continue to play a vital role as a sustainable architectural technology that simultaneously delivers energy efficiency, comfort, and architectural design.