Off-Site Construction is Radically Changing the Rules of Architectural Design

Saint-Gobain Weber Hong-Kong

(Article written in collaboration with ArchDaily)

The popularity of pre-designed and pre-fabricated homes is growing, moving much of the construction process from the building site into factories. While countries like Singapore, Australia and the United Kingdom are increasingly adopting modular buildings to meet labor and housing shortages, Nordic countries like Sweden already build 90% of residential single-family houses in prefab wood. Despite the recent surge in interest, off-site building is by no means a new concept. In fact, the construction method has been present throughout history in many attempts to consolidate its use in construction: as far back as A.D 43, the Roman army brought with them prefabricated forts to Britain, while Japan has been building in wood off-site and moving parts in pre-assemblies for at least a thousand years.

However, it wasn’t until post-World War II when one of the biggest efforts in entirely prefabricated housing occurred in the United States. Even though this successfully provided higher quality housing solutions to vulnerable groups, the method was not immune to backlash. The idea that housing is a standardized, repetitive product that rolls out of a factory instead of being crafted and personalized was heavily criticized, ultimately leading to its commercial failure. On the contrary, now prefab construction is taking over the market, not only being applied in single-family homes, hospitality and health care spaces, but also in the world’s tallest buildings.


So, why this rising interest in prefabricated construction?

The answer is quite simple: now, we can do it better. In this automated technological era, innovative digital tools are making prefabrication much easier. Design and construction are often structured and digitalized around BIM, providing an accurate, integrated representation of a building across its lifecycle while allowing the joint work of multi-disciplinary actors within a single intelligent process. Simultaneously, Open Source lets a user anywhere in the world download their favorite home design, and E-commerce platforms like Amazon or Alibaba can send prefabricated materials to the door of the construction site. Instead of creating standard repetitive buildings for different types of users, these new technologies allow clients to participate and buildings to adapt to changing needs.

Therefore, it is clear that off-site construction – with the help of digital innovation – is radically changing the rules of architectural design. This leads to some important questions: how to embrace these new “rules of the game” to put them in favor of a better global quality of life? Could this be a solution to provide greater equity in access to housing?

New architectural possibilities introduced by off-site digitalized methods

The concept of prefabrication corresponds to elements, parts or even entire buildings produced in a factory and transported to a construction site for quick installation. Every process of the traditional construction industry, which is heavily impacted by human error or the site’s difficulties and conditions, is replaced by efficient automated operations. Being a centralized process, off-site construction is faster, safer, more regulated, and requires less coordination efforts, resulting in more productivity and improved quality control. Therefore, its core benefit is that it enables a controlled, precise, and reliable process with less rework (and less surprises). In addition, increased centralization and control translates to reduced site disturbance and vehicle waste, lowering costs while minimizing greenhouse emissions.

As prefab buildings are built quicker, cheaper, and more sustainably, more people can have access to high-quality homes, especially considering that the global population will increase by 2 billion people by 2050. But, to avoid repeating past mistakes, it is fundamental to take advantage of the possibilities that digitalized, pre-designed construction can offer. It is well known that construction is a risky, expensive business that can limit innovation. But by moving it to factories and integrating digital technologies like BIM, prefab buildings can be more experimental, innovative, and respond accurately to changing needs and demands. With innovations like Open Source software, the creative process can integrate clients by providing them with an array of customizable design selections, allowing projects to adapt to these different requirements.

Ultimately, today’s prefabricated construction can leave behind the modular “one size fits all” approach by enabling a more efficient and collaborative design – allowing for greater flexibility even in an industrial process. From their part, architects must adapt to these off-site methods by collaborating with producers and focusing on aspects like urban planning, comfort, and sustainability. As the pandemic exacerbates housing shortages and the climate crisis aggravates, the rules architecture must adopt are clear: projects must be built faster, smarter, greener, and with greater adaptability (now that they can be).

Innovative materials for prefabricated buildings

The rise in off-site construction wouldn’t be possible without innovative, high-performance and lightweight materials that are also sustainable and cost-effective. Several products on the market fulfill these criteria. One example is Saint-Gobain’s Novelio Nature and Plaka. The first is an eco-friendly glass fibre wallcovering that reinforces surfaces, is highly durable and offers unlimited color options, while the second provides resistant gypsum boards for interior walls and ceiling. Both are used in a VMD Prefabricated House that is ready to order and customize online – and then built in 99 days with sustainable materials. With the highest quality standards, the project is a perfect example of what all contemporary prefabricated buildings should offer: a unique, adaptable space that is minimally invasive, durable and aesthetically pleasing.

In addition, Intrastack offers panelized, steel-frame solutions ideal for the off-site construction of multi-storey buildings, capable of building higher and faster than traditional structures with a recycled material that is 70% lighter. Following the popularity of mass timber in construction, brands like International Timber and Scotframe offer sustainable prefabricated kits, offering design flexibility, efficiency and cost-effectiveness while being a fully customizable product. Nonetheless, off-site methods aren’t limited to residential buildings, also being suitable for hotels or hospitals thanks to innovative techniques. For example, Saint- Gobain has contributed to the construction of a Catalonia hospital solely designed around pre-assembled elements, as well as providing pre-cut ISOVER F4 facades that combine external and internal insulation in the Saint-Joseph hospital in Paris.

Furthermore, even though it’s a newer segment, the interest in renovation in the prefab industry is growing in an effort to make the existing building stock more efficient – thus becoming a highly sustainable alternative. With this in mind, Glava Reform offers a fast renovation system with small prefabricated panels that provide exterior cladding, ventilation, and insulation, modernizing and re-insulating existing houses.

Towards a better quality of life through prefabricated construction

There is no doubt that contemporary off-site construction is radically changing the rules of architectural design; with prefabrication, buildings can leave behind rigid, highly invasive and risky methods that damage the environment and are unable to adapt to diverse conditions in a rapidly changing world. By integrating digital, precise and collaborative technologies with innovative, lightweight and high-performance materials, architects can deliver an appropriate response to environmental, economic and societal challenges. From a social point of view, they can provide greater equity in access to housing by offering cheaper, higher quality solutions that adjust to people’s diverse needs, even in urban environments difficult to access. From a design point of view, architects can escape conventional methods, among them former modular solutions, to adopt a digitalized prefabrication technique with greater flexibility. In this way, buildings that respond to housing shortages can still be adapted to various needs. 

Therefore, it is essential to continue exploring diverse and innovative off-site solutions in an effort to contribute to a more sustainable and creative world – and thus move towards a better architecture and a better global quality of life.