Germany Prefabricated Construction and Full Decoration Development Trends

1　Definition of Germany Prefabricated Construction 

In the German, there is no single word that perfectly matches the connotations and extensions of the Chinese term "装配式建筑" (prefabricated construction). The closest term is "Fertigteilbau", which literally translates to "prefabricated component construction" and is roughly equivalent to the contemporary meaning of "装配式建筑" in Chinese. Therefore, in this context, it is translated as "prefabricated construction".

The definition of "Fertigteilbau" by the German Statistical Department is as follows: A building is considered a prefabricated construction when a significant portion of its load-bearing exterior or interior walls is constructed using prefabricated components of floor height or room width. In evaluating whether a significant portion of the load-bearing components is made of prefabricated components, the calculation is based on the volume of load-bearing components, including the typically constructed building foundation and underground portions. This concept is crucial, and here is the original German text for reference:

Ein Bauwerk gilt im Hochbau als Fertigteilbau, wenn überwiegend geschosshohe oder raumbreite Fertigteile für Außen- oder Innenwände verwendet werden. Hierbei ist notwendig, dass der überwiegende Teil der tragenden Konstruktion ( gemessen am Rauminhalt ) aus Fertigteilen besteht. Für die Beurteilung „überwiegend“sind die meist konventionell errichteten Fundamente oder Kellergeschosse mit zu berücksichtigen.

In this passage, “significant portion of load-bearing components” can be understood as exceeding 50% of the load-bearing components. Therefore, the definition of prefabricated construction in Germany can be expressed as follows: When more than 50% of a building's load-bearing components (calculated by volume) are made of prefabricated components, the building is considered a prefabricated construction. When calculating the total volume of load-bearing components, this includes the load-bearing structures of the building foundation and underground portions.

Since the use of prefabricated construction methods in Germany does not qualify for any subsidies, there is no deliberate pursuit of the assembly rate by the developers. In cases where a project is suitable for prefabricated construction, the proportion of load-bearing components made of prefabricated structures often significantly exceeds 50%. Therefore, the relatively vague term "significant portion of load-bearing components" is considered sufficiently clear and not prone to misunderstanding when determining whether a building is a prefabricated construction in German statistical work. This is in contrast to the strict and specific regulations provided in China's GB/T 51129-2017 Evaluation Standard for Prefabricated Constructions, which defines the assembly proportions of the building's main structure, enclosing walls, internal partitions, and the overall assembly rate.

2 　Overview of Development of Germany Prefabricated Construction

The industrialization of the construction industry in Germany and other developed European countries originated in the 1920s and was driven by two main factors: The first is socio-economic factors. Urbanization demanded the rapid construction of a large number of residential, office, and industrial buildings at lower costs. The second is aesthetic factors. The architectural and design communities abandoned classical architectural forms and their intricate ornamentation, embracing a minimalist and contemporary architectural aesthetic. They also experimented with the expressive potential of new building materials like concrete, steel, and glass. Guided by the principles of urban functional zoning advocated in the Athens Charter, the construction of large-scale residential areas promoted the application of industrialized construction methods.

After World War II, due to the destruction of the war and the return of a large number of war refugees to their homeland, there was a severe shortage of housing in Germany. To address this housing shortage, Germany utilized the Precast Concrete (PC) Slab Technology to construct a large number of multi-story and high-rise residential buildings (see Figure 1). These slab buildings made a significant contribution to alleviating the housing shortage at the time. However, today, they are not well-received, and many of these slab residential areas that lack maintenance and updates have become gathering places for the socioeconomically disadvantaged, leading to high crime rates and other social problems. This has drawn strong criticism from the public, making them a priority for urban renewal and transformation. In some areas, extensive demolition of these slab buildings has already begun.

Figure 1: The Munich Olympic Village, Constructed in 1972, Represents a Relatively Successful Assembly of Buildings in Germany.

Compared with conventional on-site cast-in-situ construction methods, precast concrete slab technology is more expensive, resulting in buildings that lack individuality and are less capable of meeting contemporary aesthetic requirements. Since the 1990s, Germany has largely ceased using this technology. Instead, there has been rapid development and greater application of precast concrete composite panel technology.

Germany has a significant number of multi-story buildings. In traditional cast-in-situ concrete construction, the use of formwork, form removal and surface finishing is labor-intensive and costly. In contrast, concrete prefabricated composite floor and wall panels, when used as templates for floors and walls, in combination with some cast-in-situ work, offer structural integrity. Precast concrete panels have a high level of surface smoothness, reducing the need for plastering and leveling processes. This results in cost savings and high construction quality compared to entirely cast-in-situ projects, which is why they have gained widespread use.

In contemporary Germany, most public buildings, commercial buildings, and residential projects are built with a mix of cast-in-situ and prefabricated components or reinforced concrete structures, tailored to the specifics of each project. The focus is not on achieving a high assembly rate but on finely optimizing the planning, design, and construction processes to seek a balanced blend of project individuality, cost-effectiveness, functionality, and eco-friendliness. As industrialization progresses and BIM (Building Information Modeling) technology is increasingly applied, the level of industrialization in the construction industry continues to rise. More and more building components are factory prefabricated and installed on-site, accounting for a growing proportion of the construction sector.

3　Statistics of Germany’s Latest Prefabricated Construction and Related Interpretations