Mr. Sun Kefang, Chief Advisor of the Industry Chain Innovation Cooperation Branch of the All China Real Estate Chamber of Commerce and Deputy Chief Engineer of the Residential Industrialization Promotion Center of the former Ministry of Housing and Urban-Rural Development, delivered an insightful speech titled “The Rise of Construction and Decoration Industrialization” at the 6th China Real Estate Industry Chain Innovation Cooperation Summit Forum.
In his address, Mr. Sun highlighted the three major leaps necessary for the industrialization of housing, as well as the three critical steps China’s prefabricated buildings must currently undertake. Below is a transcript of his compelling speech.
Mr. Sun Kefang
Forum Transcript:
Three Major Leaps in the Industrialization of Housing
All equipment and decoration-related aspects are evolving due to increased demands from the public.
The three critical leaps in the industrialization of housing are as follows:
1. Achieving Low Energy Consumption in Chinese Residential Buildings
Germany has spent 20 years on this journey and is still progressing. China aims to cross this threshold too, but 20 years may not be sufficient—it might take 30 years to achieve this goal.
2. Realizing Modular Integrated Assembly in Residential Construction
This involves componentization, which goes beyond current structural components to include modularizing all parts. For example, as Mona Lisa demonstrated, transforming boards into modular units is crucial. Rather than manually assembling piece by piece, prefabricated house components should be modularized in factories and then assembled on-site, embodying true assembly.
Adopting this approach means moving away from traditional wet construction methods. This industry needs industrialization—prefabricated housing alone accounts for over 3 trillion yuan nationwide, excluding interior decoration.
3. Bidding Farewell to Unfinished Houses and Achieving Full Decoration
In 2012, a document titled “Guidelines for the One-time Completion of Commercial Residential Decoration” was introduced (authored by Mr. Sun). Over the next 5 to 8 years, rough houses will be phased out in large and medium-sized Chinese cities.
Since 2002, legislation to abolish rough housing has been proposed multiple times. On October 1, 2016, Zhejiang Province issued the first official document to completely reject unfinished houses in new residential buildings. Today, several provinces and cities have followed suit, making unfinished houses unacceptable within the industry.
The public now demands rapid renovation, making decoration increasingly important. Therefore, eliminating unfinished houses is a priority.
This transformation is systematic: internal parts, assembly equipment, and modular components such as floors, ceilings, plumbing, and electrical systems are all integrated.
However, a major issue remains—many poorly executed prefabricated buildings embed all pipes inside concrete, leading to significant challenges like drilling holes and creating openings that compromise structural integrity. When demolishing unfinished houses, the damage is severe, posing greater problems than currently recognized.
Three Steps China Needs to Take in Prefabricated Construction
1. Prefabricated Buildings Must Rely on Concrete
In Japan, steel reinforcement is widely used. Cast-in-place concrete requires higher standards for precast concrete: concrete grades must be elevated, typically from C25 or C30 to C40 in China. Steel reinforcement also needs strengthening.
For example, in Japan, steel bars have increased from 28 cm to 42 cm in diameter, with concrete grades reaching C60. High-grade cement and mortar have significantly improved seismic performance. This is why China’s Ministry of Construction encourages the use of high-standard concrete.
Large sleeve holes, which improve joint filling, are rare in China but essential in earthquake-prone areas. Critical structural nodes like ceilings, walls, and columns are cast-in-place, a key feature of current prefabricated components.
Vertical components are common in China, whereas Japan favors frame structures with careful sealing and grouting of joints to ensure structural integrity.
Not all buildings in Japan are fully prefabricated with cast-in-place concrete. Structures under 18 floors and underground facilities still rely heavily on cast-in-place concrete. Currently, China’s prefabricated buildings stand at about 30% completion.
Claims that prefabricated components abroad achieve 80% usage are exaggerated. For instance, villa roofs are prefabricated, but the rest is not. Wall panels, sometimes two stories high, are rare in China.
In China’s shear wall structures, all critical black-colored areas must be cast in place to ensure safety, as these are stress points. The steel bar usage is minimal, and joints are often inadequately filled or welded, which compromises safety—something Japan avoids by using higher standards and welds.
Japan’s craftsmanship level in this regard is unmatched.
For example, a small high-rise in Japan uses semi cast-in-place concrete with cast-in-place flooring and prefabricated stairs. Beams are tied on-site and lifted into formwork for concrete pouring. This method is considered semi-prefabricated.
2. Assembly Must Synchronize with Increasing Strength
Steel bar diameters have increased from 28 mm to 42 mm to ensure a 100-year lifespan. Because larger steel bars can collide with columns, Japan employs BIM modeling to design and visualize the assembly process.
In Japan, prefabricated components are manufactured in specialized factories, such as pre-fabricated beams shown here.
China faces challenges with veneered tiles, whereas Japan often hangs face bricks rather than pasting them, preventing detachment during earthquakes. Exterior walls are strictly regulated for fire prevention, as fires cause more fatalities than earthquakes in Japan.
To ensure longevity, protective layers are thicker (about 5 cm) with robust steel bars. Japan uses steam to test every grouting hole for obstructions, a simple yet effective safety measure that China has yet to fully adopt.
At the mixing plant, Japanese manufacturers use ultra-strong steel bars, demonstrating advanced material standards.
3. Prefabricated Residential Buildings Must Align with Industrial Decoration
This point is often overlooked in official documents but is crucial. Prefabricated buildings lacking industrialized decoration are considered incomplete.
Developers must recognize that full decoration is essential for environmental protection, safety, energy conservation, and user experience.
President Zhao invited me to emphasize this meeting’s significance. Future decoration units will become integral to buildings.
Under large-scale contracting, developers will focus on real estate development, while decoration will be contracted to specialized companies. This approach ensures more efficient procurement and higher quality.
The Federation of Industry and Commerce’s procurement team aims to serve as a flagship platform for real estate companies, simplifying sourcing and ensuring reliability. Currently, real estate companies entrust prefabricated components to manufacturers like Yuanda, a manufacturing entity.
New Decoration Methods Are Essential
Decoration must evolve into a complete, scaled, assembly-line process rather than scattered efforts.
Standardization is key: products should be uniform within and across buildings to improve efficiency and reduce errors.
For example, Vanke constructed a 90-square-meter unit in Beijing with limited floor and unit layout options, offering a classic and well-researched design that sells well.
The goal of decoration is to minimize wet work and repetitive tasks, streamlining processes through scientific management and assembly-line principles.
Improved precision increases conformity and accuracy, reducing complications.
Industrial design and decoration design must be integrated. Separation leads to decentralized pipelines and undermines efficient decoration.
In Japan, after constructing the main structure, concrete is poured on top, followed by exterior walls and internal insulation. Exterior walls are fire-resistant thanks to materials like sponge-based putty covered with gypsum board.
The fresh air system is incorporated, and multiple floors are layered with plumbing, heating floors, and insulation, all designed for easy maintenance without wall demolition. Japanese houses come in various styles, including combined styles with tatami mats.
Workers manually assemble parts like kitchen cabinets, which are semi-industrialized with standardized sheet metal components. Bathrooms are delivered as finished products.
Compared to Japan, Chinese and European homes often lack features like suspended ceilings and soundproofing. Europeans, including Sweden and Norway, have homes with less robust security compared to China.
Chinese anti-theft doors are stronger, while European doors are thinner and easier to breach. Fire safety and evacuation are often overlooked in China; for example, elevators are improperly used during fires, increasing risk.
In Japan, fire safety includes escape options like soft ladders hidden behind panels, checked regularly, allowing residents to evacuate to lower floors safely.
Chinese homes often conceal steel structure corners during decoration, but Japanese homes seamlessly integrate large steel pillars into their design.
China has advanced technologies for external walls and internal insulation, including elevated floors and integrated pipelines.
Green Building and Decoration
As a member of the National Green Committee, I have stressed that evaluating green buildings without considering decoration is meaningless. Green building ratings allot 20 points for environmental performance, but without decoration, these scores lack value.
For example, expensive paint is not enough if furniture and other interior elements exceed safety standards. Purchasing quality furniture, preferably domestic or Japanese brands, is more critical.
Decoration is like adding underwear before outerwear—it’s essential for overall quality and safety.
Organizing the decoration industry through a procurement platform can create a flagship that serves all real estate companies, achieving environmental and procurement standards.
While online procurement has potential, face-to-face, onsite procurement remains crucial—much like why clothing stores exist despite online shopping.
We must cultivate a mindset of building century-old architecture with a responsibility to future generations. Creating greener, longer-lasting homes is the hope and dream of all builders.
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