Urban Context in Bukit Timah District
In the upscale Bukit Timah district of Singapore, a distinct contrast emerges in the design of one particular concrete building that sets itself apart from the prevailing architectural style of the area. While the semi-detached houses built in the 1990s are characterized by ornate façades and intricate detailing, this project takes a different and unique approach.
Innovation in Construction: The 3D Printing Experiment
The building, known as “QR3D”, is the first house in Singapore to be constructed entirely using 3D printing technology. Spanning 6,130 square feet over four floors and featuring seven bedrooms, the project stands as a model that fuses technology with functionality. It is not merely a display of innovation but is purposefully designed to serve as a livable family home.
Design Philosophy and Project Objectives
Architect Lim Koon Park, founder of Park + Associates, emphasizes that the goal was not solely a technical experiment. He believes that technology-driven architecture often falls into the trap of either adopting uniform formal efficiency or pursuing experimental designs that lack livability. Therefore, the focus was on creating a more intricate and refined design that genuinely addresses practical living needs while effectively harnessing advanced technology.
Collaboration and Challenges in the Post-Pandemic Era
The “QR3D” project was launched through a two-year collaboration with CES_InnovFab, a local company specializing in 3D concrete printing. This partnership came at a critical time, as Singapore’s construction industry faced significant challenges, including labor shortages and rising costs in the aftermath of the COVID-19 pandemic. These pressures fueled the search for innovative technological solutions.
Design and Construction Methodology
Architect Lim’s long-standing interest in alternative building materials and construction methods played a pivotal role in this project. He approached the design as if it were a conventional house, making the necessary technical adjustments later to accommodate the requirements of 3D printing.
Division of On-Site and Factory Work
The construction process combined two integrated approaches:
• On-Site Construction: Some walls were printed directly on-site using a concrete printer protected from Singapore’s heavy tropical rains, with layers of concrete deposited successively.
• Factory Construction: Other components were fabricated in a controlled factory environment and then transported to the site by truck.
This approach significantly reduced the need for large labor teams typically required for traditional tasks such as installing wooden molds, bricklaying, plastering, and painting. As a result, the overall process was streamlined, and operational burdens were minimized.
Design Challenges of the Conical “Oculus”
The “Oculus” element in the house stands out as one of its most striking architectural features—a conical void rising nearly six meters high. However, this tilted design posed significant technical challenges for the team. Architect Lim Kon Pak explained that directly printing such a shape was extremely complex, as concrete tends to collapse when printed at certain angles.
Innovative Technical Solutions through Partial Printing
Instead of relying on fast-setting concrete mixes that are not yet commercially available, the team adopted an innovative strategy: they printed bricks or small modular components for the inclined sections, which were later assembled on-site. This method successfully overcame the technical difficulties associated with steep angles.
A Steep Learning Curve and a Unique Experience
Working with 3D printing was a new experience for the team, requiring significant problem-solving and close collaboration. Lim noted that improvisation was sometimes essential, especially in challenging situations like printing near shared walls, where the movement of the printer nozzle was restricted. Nevertheless, these difficulties made the project all the more rewarding, as the team discovered practical solutions in real-time, creating a unique and highly educational experience.
Simplifying Construction and Reducing Waste with 3D Printing Technology
Architect Lim emphasizes that traditional construction methods require complex coordination among multiple specialists, which increases project complexity and can be overwhelming for supervisors. In contrast, 3D printing significantly simplifies the process by eliminating the need for several overlapping work stages to build a single wall. There is no need for wooden formwork, bricks, or unfinished walls, which results in less material waste, lower labor costs, reduced noise, less site traffic, and minimal dust. These advantages could become key motivators for broader adoption of this technology in the construction industry.
Smart Design for Indoor Climate Regulation
The house incorporates a natural and simple temperature regulation system perfectly suited to Singapore’s tropical climate, without relying on complex air conditioning systems. The “Oculus” is a unique architectural feature that not only enhances the visual appeal but also serves a critical functional role. It allows natural light to flood the space while facilitating the upward movement of hot air, which is passively expelled through a turbine exhaust fan, improving indoor ventilation.
An Emotional Dimension Beyond Architectural Function
The “Oculus” also carries significant emotional value within the home. Lim describes how the dining area, located beneath this conical void, experiences a shifting atmosphere throughout the day. During thunderstorms, the space becomes dramatic, while at sunset, it transforms into a calm and contemplative setting. This dynamic interaction with light and weather brings a personal and vibrant quality to the space, turning each meal into a unique sensory experience.
Interior Design Harmonized with the Central Void
The house unfolds as a carefully orchestrated sequence, where every space is connected to the large central void—the Oculus. The floor levels gradually shift and vary with intention, creating a dynamic interplay between feelings of compression and openness across different areas. Ceiling heights also fluctuate, from 9.5 feet in the indoor terrace to create an intimate atmosphere, to 16.5 feet in the family gathering area to evoke a sense of spaciousness and freedom. Glimpses of the Oculus appear from unexpected angles, subtly drawing the occupants’ attention and reinforcing the interconnectedness of the spaces within the concrete envelope.
Material Selection and Finishes: A Narrative of Sustainability
The materials used in the construction reflect a clear commitment to sustainability without being ostentatious or forced. The structural concrete harmonizes with the 3D-printed elements, while the flooring varies between large-format tiles, recycled composites, and engineered treated wood. Notably, the powder room floor features discarded marble chips sourced from a local supplier’s waste, adding a unique ecological and tactile layer to the design.
Smart Environmental Considerations in Exterior Design
The design thoughtfully integrates key environmental strategies. The western façade shares a common wall with the neighboring house, shielding the interiors from harsh afternoon sunlight. Deep arches provide shading for the southeast-facing areas, while limited openings in the bedrooms reduce heat gain, enhancing the home’s cooling efficiency. Additionally, the house benefits from a heat pump water heater that expels cool air as a byproduct into the upper-level spaces, further contributing to thermal comfort.
Revealing Technology Instead of Concealing It
What sets this project apart is architect Lim’s philosophy towards technology. He rejects the idea of hiding the technology behind traditional finishes. The ribbed surfaces that reveal the distinct layers of 3D-printed concrete—resembling geological strata—are deliberately left exposed without plaster or paint. This choice signals a departure from the obsession with perfectly polished finishes, embracing instead the construction process itself as an integral part of architectural expression.
Reading the Building as a Document
Lim explains this concept by saying, “You can literally read how this house was built.” The visible layers serve as a visual record of the construction process, offering observers a deeper understanding of the technical and artistic journey behind the build.
3D Printing as a Step Toward the Future
Lim’s architectural education spans Singapore and the United Kingdom, with studies at the National University of Singapore, the University of Sheffield, and The Bartlett at UCL. He views the QR3D project as a first step in a long journey toward integrating 3D printing technology into urban architecture. Through this project, he aimed to prove several key points:
- 3D printing can succeed in contemporary architectural projects within cities.
- It can create high-quality spaces that feel human and emotionally engaging.
- This modern technology can contribute to building homes that remain functional and livable for decades to come.
Education and Research: Pillars for Technological Advancement
Lim emphasizes that the technology required for 3D printing is currently available, but he stresses that what is lacking are intensive efforts in education, awareness, and research and development. These factors are essential to generate momentum and wider adoption of this technology in traditional and mainstream architecture.
Project Diversity and Expanding Horizons
Lim’s office undertakes a wide range of diverse and unconventional projects, spanning from multigenerational complexes in Singapore, environmental retreats in natural settings such as Fiji’s “Sleeping Giant” mountain, to entertainment complexes in Saudi Arabia. This diversity reflects a desire to explore multiple applications of modern technologies within different architectural contexts.
QR3D: A Technological Advancement with a Human Touch
With the QR3D project, Lim managed to create a unique model that combines technological innovation with a warm human touch. The project is described as a “concrete poem” that celebrates both innovation and memory, using the language of architecture to embody the concept of “home” as a place filled with intimacy and sensory experience—far beyond a mere technical achievement.
