In this blog post, we’ll explore the concept, principles, advantages, and design standards of the Passive House, as well as its significance for the future of architecture.
What Is a Passive House?
South Korea is one of the countries that consumes a significant amount of energy for winter heating. Heating energy consumption varies greatly depending on a building’s insulation performance and construction methods, and energy conservation in the building sector is considered a critical challenge in terms of achieving national carbon neutrality and improving energy efficiency. For these reasons, interest in Passive Houses is steadily growing within South Korea’s construction industry.
A Passive House refers to an eco-friendly architectural concept that maintains a comfortable indoor environment—primarily in terms of indoor temperature and humidity—by maximizing the use of the natural environment and the building’s inherent performance, without relying on separate, large-scale heating and cooling systems. In contrast, an Active House refers to an architectural concept that actively utilizes mechanical systems to provide heating, cooling, and ventilation. Although many high-efficiency buildings that harmoniously combine these two concepts have recently emerged, the Passive House stands out because it focuses above all on maximizing the building’s inherent performance.
The greatest advantage of a Passive House is its ability to significantly reduce heating energy consumption. Compared to conventional buildings, it can cut heating energy use by as much as 80–90%, and the reduction in fossil fuel use also leads to a significant decrease in carbon emissions. Thanks to these characteristics, it not only reduces building operating costs but also has a positive impact on addressing climate change.
The concept of the passive house was established in the late 1980s by Wolfgang Feist of Germany, and since then, full-scale research and adoption have taken place, primarily in Germany. Currently, various types of passive houses are being constructed not only in Germany but also in many countries around the world, including throughout Europe, North America, and Asia. In South Korea as well, the number of passive houses and zero-energy buildings is steadily increasing, particularly in residential and public buildings.
The basic concept of a passive house is very simple: it involves retaining as much heat as possible—whether generated inside the building (such as body heat) or entering from outside (such as heat from appliances or solar radiation)—to minimize the energy required for heating. Based on this concept, the Passive House Institute (PHI) in Germany grants passive house certification to buildings that meet specific performance standards. Current certification standards are continuously being improved, and various evaluation methods are applied depending on the building’s use and climatic conditions.
What criteria must a Passive House meet?
A Passive House is not simply a building with thick insulation. It must meet various design criteria to achieve a specific level of energy performance.
Most notably, the U-value of the building’s exterior walls and windows must be kept very low. The U-value indicates how easily heat transfers through walls or windows; the lower the value, the better the insulation performance. Additionally, the building’s airtightness must be enhanced to minimize unnecessary inflow of outside air, and strict airtightness tests are conducted to ensure this.
Furthermore, installing high-efficiency heat recovery ventilation systems to recover heat lost during ventilation, and designing to minimize thermal bridges, are crucial elements. Heat loss from piping and structural elements must also be minimized as much as possible; only when all these factors are comprehensively met can the high energy performance of a passive house be achieved.
How does a Passive House save energy?
The basic principle of a Passive House is very simple: it minimizes heat loss through heat exchange with the outside environment to retain the already warmed indoor air for as long as possible. To achieve this, the most important factor is installing high-performance insulation to a sufficient thickness to minimize heat escaping to the outside. A much higher level of insulation performance than in conventional buildings is required. Recently, as the performance of insulation materials has continued to improve, products have been developed that can achieve the same or even better insulation effects with thinner layers than in the past. These technological advancements play a crucial role in increasing energy efficiency while reducing the thickness of building walls.
Another effective method is to use high-performance windows and doors that offer excellent airtightness and minimal heat loss. This blocks drafts and minimizes thermal bridging, thereby preventing indoor temperatures from dropping. Passive houses typically use high-performance windows and doors featuring triple-pane glass with Low-E (Low Emissivity) coatings and filled with inert gases such as argon or krypton. In addition, the orientation of the building is carefully considered so that main living spaces are positioned to maximize the use of solar radiation, and high-efficiency heat-recovery ventilation systems are installed to recover and reuse heat lost during the ventilation process. Furthermore, overall energy efficiency is further enhanced by minimizing heat loss from piping and equipment and by recovering and utilizing waste heat from various parts of the building.
Could the passive house be the answer to the future of architecture?
The ultimate goal of passive houses, with their outstanding energy efficiency, is to realize a “Zero Energy House” that minimizes or eliminates the use of fossil fuels. Recently, Zero Energy Buildings (ZEBs)—which combine solar power generation, energy storage systems (ESS), and high-efficiency equipment—have been expanding globally, and South Korea is also expanding their adoption, primarily in public buildings, through the operation of relevant certification systems.
However, since the current concept of the passive house has evolved based on the climatic conditions of Europe, including Germany, a wider range of design techniques must be applied in South Korea, which is characterized by a hot and humid summer climate. In particular, technologies for reducing cooling energy consumption and controlling humidity require ongoing research and improvement. Furthermore, since initial construction costs—including high-performance insulation, windows, and ventilation systems—tend to be higher than those of conventional buildings, it is necessary to gradually reduce the financial burden through the advancement and widespread adoption of these technologies.
Nevertheless, the significance of the passive house is immense. Today, as energy demand continues to rise and addressing climate change has emerged as a critical challenge, maximizing energy efficiency to reduce unnecessary consumption is far more important than simply producing more energy. From this perspective, the passive house can be considered a representative architectural concept that points the way toward sustainable future construction.
