Prefabricated Housing is the Future of High-Quality Affordable Housing

By. Architecture Solutions Specialist Chad Dunsby, edited by Jeff Jones, PMP CE

The housing crisis is quickly becoming a worldwide problem, particularly in terms of affordable homes which may reach a tipping point in the immediate future. The cost of living in many metropolitan areas around the world is already beyond the scope for a lot of people today. One of the primary causes is the lack of available units. Whether it be single-family/detached homes, condominiums or other alternative residences, there is just not enough supply to meet the growing demand, and simple economics always shows this will inflate prices.

To mitigate this, numerous new and existing companies globally are in full start-up mode working diligently to disrupt the construction market by creating architecture that can be both designed and produced internally. This is happening in increasingly automated factories that are leveraging current and ever-evolving technology. Many producers are using a series of prefabricated modules that are adaptable and can be combined and deployed in any number of configurations and designs.

This process will not only be a disrupter in the market but will be a full-on wakeup call for the entire design industry once this type of manufacturing is optimized and at full production capacity. Imagine a world with high-quality houses that will be designed and built in a matter of weeks instead of months. Beautiful, versatile units will be fully assembled on a site of choice with a cost that is significantly lower than that of traditional construction, allowing for high construction precision and quality. The capability of building entire subdivisions or cities in less than half the time it currently takes, with significantly less waste, is both groundbreaking and exciting, and not totally out of the realm of what the future may hold for the global housing construction market.

Design Process

Forward-looking companies are pushing the use of their 3D design software, such as Revit, to design houses in a modular process that can be broken down into individual components that can be purchased, shipped and either installed on-site or manufactured on the factory floor depending on costs. These modules can be combined to create single-family houses or creatively constructed in several ways to form more complex units for a multifamily assembly such as townhomes, or even a large-scale multifamily residence.

Design software has developed to a point that allows for every component of a building to be represented in 3D at a 1:1 scale. This allows for greater foresight and addressing of construction issues before anything is assembled. Continual preconstruction clash detection, which has traditionally only been used for large scale construction projects, is being used more and more in single-family construction. Prefabricated modules require a more detailed than typical design process to coordinate, ensuring a higher degree of precision. Once complete, the design can be used for multiple builds as well as in combination with different modules to produce unique building layouts and architecture.

Design production software with developed plugins allows for the capability of real-time cost estimates during the design phase with greater accuracy than what is produced by traditional construction estimators. By creating real-time counts and precise estimates of quantities, teams can calculate every single item a manufacturer will need to build a module down to the exact quantity of screws.

Manufacturing Process

For the building process,  companies are using 3D design software to send their designs to an automated Numerical Control/Automated Control (CNC) machine which “prints” the walls, floors, roofs and other elements of the house in the factory. It is then “box assembled” into a module while factory laborers work on the exteriors and interior finish work, a process that decreases time, nearly by half, and resources, compared to traditional assembly.

In terms of construction time, a custom-built home averages about 10 to 16 months to build. A developer-built house will take around six to 12 months. Alternatively, a factory-built, prefabricated three-story house (consisting of the first floor, second floor, and third floor/roof) can be produced in the factory in under three weeks for a first initial test run followed up by an examination of the design/manufacturing process. The modules are then shipped to a site where deployment and module connections can take less than two weeks.

Prefabricated factory-built construction allows workers to be placed in any number of shifts in a well-lit, climate-controlled area, eventually creating a 24-hour-straight production timeline. This also allows the Site Foreman/General Contractor to have greater control/oversight of the construction team. Additionally, isolating repetitive tasks increases the overall consistency and quality of the build and will improve the durability and appearance of manufactured items. This can be achieved by constant monitoring and studying of the manufacturing process to better improve it for the next run of components.

Cost Savings

Companies are in business to gain a competitive advantage and ultimately make money. This is why cost always comes into play with design. With construction of prefabricated houses, the costs will ultimately be less than traditionally built ones. These cost savings are achieved in several different ways once full production cycles are implemented.

First, being able to have an extremely accurate estimate/bill of materials allows companies to pre-order materials beforehand and have all necessary supplies accessible prior to construction of the modules. Therefore, procurement departments can reduce costs by seeking bulk price breaks and purchasing items at discount. Accurate estimates prevent the storage of surplus, unneeded construction items, and provide a beneficial impact on the environment by reducing waste and eliminating overproduction/overconsumption.

When builders know the exact amount of materials required to build a module they can significantly reduce construction waste. For example, project leaders will have the capability to identify how much lumber is needed to build the partitions for a module in a particular home and will factor that into manufacturing and assembly timelines. Having a dedicated team of assembly laborers working on the same tasks will reduce or almost eliminate construction errors and rework. Creating standardized parts in the shop as well as increasing productivity and decreasing errors will reduce the hours required for manufacturing. Finally, prefabrication will assist with budgeting, capital costs, and cash flow management, which will drive better decision making, such as with the timing of bulk purchases and other items.

Summary

The construction industry is and has always been kind of ‘old school.’ It is certainly one of the last industries to embrace and be truly disrupted by, technology and innovation. It is also an industry that is hesitant to adopt changes. The industry is notorious for being quite often bogged down by project delays, inefficiencies, quality concerns and cost overruns, and it is time for a change. Taking the next step to design and construct as much as possible prior to site delivery in a highly-advanced, controlled factory environment alleviates a lot of these ongoing issues and signals the next big push into the future of residential construction.