Prefabrication Could Make Housing Construction More Affordable

Prefabrication is the process of assembling elements, parts, or whole buildings in a factory before being transported to a site to be installed quickly. Prefabrication offers many advantages over traditional methods of construction, including speed, accuracy in execution, efficiency and cleanliness. The primary human need for housing is apparent. Industrial methods have always been of interest to architects. These industrial methods can be used to build affordable, high-quality housing on a variety of scales. The question is whether prefabrication can be used in construction to increase equity in housing access, as it has been tried many times throughout history.

Minimod / MAPA. Image Cortesia de MAPA
Minimod / MAPA. Image © Leonardo Finotti

This idea is not new. Frank Lloyd Wright, Jean Prouve, Le Corbusier and Walter Gropius are some of the architects who have successfully integrated housing construction with this sector. The latter deserves special mention for his efforts in this area. The publication “The Dream of the Factory Made House”, written by Walter Gropius, Konrad Wachsmann and edited by MIT Press, gives a detailed overview of the experiences of the two German architects and highlights their successes and setbacks. The Packaged House System was developed by the two. It is a prototype that shows ingenuity and can be expanded or reduced as required. Unfortunately, it did not survive commercially.

Minimod Curucaca / MAPA. Image © Leonardo Finotti

Gropius’ quote in Brazil’s 1929 book Bauhaus: novarquitetura offers an interesting perspective on the subject. “Just like today 90% of the population no more thinks about ordering made to measure shoes, limiting their use to mass-produced products as a result improved manufacturing methods, so will the future individual be able to choose the most suitable dwelling from the stock.” Modern technology may be able to accomplish this task but not the economic organization in the construction industry, which remains entirely dependent on manual labor methods and doesn’t reserve a less limited role for the machine.” Gropius’ prediction was clearly not realized. In particular, Gropius predicted that the industry would remain highly artisanal, and is considered to be extremely resistant to technological changes and incorporations.

Salas Modulares da International School of Palmela / Estúdio AMATAM. Image © Sérgio Garcês Marques

This has all changed. There are two types of pre-made elements. The first covers pre-dimensioned panels and elements that make it easier to transport and customize the building. 3D prefabs are three-dimensional structural volumetric systems which can be combined on-site to cover other units and systems.

Modular construction: From products to projects, starting in 2019, argues that modular (or prefabric) construction is not new, but technological advancements, economic demands, and shifts in mindset mean that it attracts unprecedented interest and investment. Modular construction could provide a significant boost in productivity and help solve real estate crises across many markets. It also has the potential to significantly change the way we build. The paper points out that modular projects have a proven track record of speeding up project schedules. Modular construction can accelerate construction by as much as 50%, and can even cut down costs by as much 20% if the tradeoffs are right. Modular construction can also lead to significant cost savings. However, this is still a rare approach.

Escritório Modular Tini / delavegacanolasso. Image © Imagen Subliminal (Miguel de Guzmán + Rocío Romero)

Prefabrication and modularity allow the base work to be completed while the rest is being built in the factory. The process at the construction site is quick and usually involves heavy machinery to lift the structures. Construction times are shorter, there is more predictability and less labor required, and the site produces less waste. This results in lower final costs and quicker ownership for commercialization. Costs can decrease over time as new processes, tools, and technologies are developed. However, this does not mean that material quality is compromised. This allows for greater efficiency that can significantly lower long-term costs.

Pré-fabricados de 1000m² / SUMMARY. Image © Fernando Guerra | FG+SG

Many critics of prefabricated systems point out the monotony and repetition that they find objectionable. They argue that modularity can limit creativity and homogenize architectural production. Samuel Goncalves says in this interview that “more than conditioning creativity,” these systems can also cause a change in design processes. This is not always a bad thing or limiting. Prefabricated architecture is different. Instead of imagining a project, and then thinking about how to build it in traditional architecture, this process is reversed. This means that we must first understand the system and how the components are transported, manufactured and assembled before we can look at the final form of construction. Prefabricated architecture is different. Form determines the construction system in traditional architecture.

Casas para todos - Dortheavej Residence / Bjarke Ingels Group. Image © Rasmus Hjortshøj

Gropius expressed concern in this regard but also defended standardization and adaptability as not being dichotomous concepts. “Mass housing requires mass production. The architect must learn how to work with industry. Standardization is inevitable in the housing industry. We should not resist it, as standards are the norms for civilized communities and allow them to express themselves. We must remember that each person has different needs and wants, and we should allow people to choose within the boundaries of social consensus. The world of man and his environment are constantly changing. Industrial dwellings must be able to adapt and respond to changes and growth. The industrialized housing system must be designed to maximize utility, standardization, interchangeability, and variability of the components and the final product, the house. This industrialized building system moreover is not an end in itself but an integrated part of a larger whole, one level in a hierarchical environmental-social-economic system.”

They are not a common feature of architecture history, but the modular structures that did get off the ground eventually waned. This is evident in the history of American catalog homes. Prefabricated systems are available in a variety of materials. These include prefabricated rooms and buildings, which can be assembled quickly. Brazil is an example of this. Prefabrication has become more popular in large programs like schools and hospitals. Joao Filgueiras Perula’s research deserves more attention. There are some excellent examples of prefabrication for single-family homes. However, these are less impressive and more experimental.

It is important to consider the specific circumstances of each place when examining construction systems, technologies and materials. There are many factors that affect the feasibility of a solution. In developing countries, costs can be quite different than in developed countries. Many times, the cost for materials, equipment, and technology in developing countries is higher than the cost for labor. Prefabrication is a common practice in Japan and the Nordics for many decades. However, these technologies are still very young in countries where low-skilled labor costs are affordable. Not only is affordability a matter of building technology, but also of the cost of housing. The land price is a major factor in the cost of a house. This is influenced by the proximity to urban amenities and the location. This issue must be addressed when discussing access to housing.

Prefabricated components and structural systems are highly efficient at ensuring minimal material use with maximum structural benefit. However, this requires detailed and more comprehensive projects that can be done through BIM. In order to meet the current demands for sustainability and productivity, designers, manufacturers, and entrepreneurs will need to make changes. Prefab buildings are a great way to create beautiful and sturdy structures that can be used for housing construction and other miscellaneous purposes. For greater acceptance, it is crucial that technology incorporates local materials, knowledge, and respects the unique characteristics of each area.