Innovations in Prefabrication and construction
The construction industry has never been one to embrace change quickly. However, with outside factors such as skilled labor shortage, tight schedules and budget overruns impacting the industry today, change is inevitable.
Prefabrication is the practice of assembling components of a structure in a factory or other manufacturing site, and transporting complete assemblies or sub-assemblies to the construction site where the structure is to be located.
Construction elements and modules are produced off-site in factory-like settings, transported to site and assembled there. The prefabricated units may be e.g. smaller elements in a façade or entire factory-fitted bathrooms.
Prefabrication refers to the manufacturing of construction elements away from the construction site and assembly on site. In principle, these prefabricated elements can be customized for the specific project.
With precast concrete you can use the mould as many identical panels as you require. The process is quick, the factory setting facilitates the setting up of good quality control arrangements.
Prefabs and the modernist movement
Designed by architects, constructed in factories and trucked to their sites, these houses had the look the couple wanted, at a lower price.
Over the past years, though, spurred by a handful of architects and Dwell and Sunset magazines, a hipper, greener, more carefully designed version of the prefabricated house has proliferated, at least on drawing boards.
So who's buying the prefabs?
Yet many of the prospective buyers have been baby boomers — “a lot are empty nesters who want to downsize.” There are various obstacles to producing modernist prefabs on a large scale, from factory capacity to local building codes to hesitant lenders. And the sort of people who might buy them tend not to be inclined to live in a homogeneous tract of identical houses, which may limit the potential for mass development.
In the meantime, the first generation of modernist prefabs are anomalies made to order. “We feel like we’re the first to see the band and get their album,” says Christian Overfield, a Los Angeles college instructor who will move into a prefab with his wife and daughter this summer. “When we tell people that our home is going to be delivered, some think it’s weird, but I can’t wait for it to pull down the street.”
Advances in Prefabrication
Prefabrication isn’t new. The first use dates back to the 1800s. Almost 50 years later, two of Sweden’s most recognizable brands teamed up to create prefabricated BoKlok houses for the Scandinavian market. While affordable, many thought the houses lacked aesthetic appeal.
This led to the stigma that is often attached to modular as standardized, mass-produced buildings. Today, this stigma couldn’t be further from reality.
Prefabrication has advanced significantly and offers high-quality finishes, aesthetic versatility and, most importantly, design flexibility. It’s also making a positive impact on construction projects in the following ways:
- Reducing labor costs. Work can be done by fewer highly skilled workers in a safer and more productive environment with better quality control.
- Saving time. Prefabricating components offsite can deliver a project 30% to 50% faster than traditional methods, according to the Modular Building Institute.
- Reducing risk. Nearly half of firms using prefabricated or modular construction found improvements in site safety.
- Reducing waste.
- Reducing site impacts. Fewer workers and less equipment lead to reduced traffic onsite, fewer parking spaces needed and less material staging areas.
- Delivering cost certainty. Because players align on project requirements from the beginning, the collaboration and transparency give all parties visibility into factors affecting the budget’s bottom line.
- Increased safety to workers
- Over-engineering e.g. wall thickness as several modules are assembled
- Limited ability to change the structure through future renovations
Prefab and Construction impact
The design phase is affected somewhat restrict the number of possible designs. The construction phase will become more efficient, as more of this process will take place in factory-like environments.
In the field, it’s common to hear the words “prefabrication” and “modular” referring to two different things. In reality, prefabrication is a much broader category that includes modular construction.
Challenges when using prefabrication
- Mass Production / Limited Variety – Naturally, apartment buildings, offices, high-rise building and hotels are likely candidates if each unit can be standardized and stacked.
- Higher Amount of Complex Decisions / Front Loaded Design – modular demands that more decisions and greater design and engineering be completed up front in the process. It requires architects, engineers and contractors to be familiar with the intricacies of the modular fabrication.
- Approval Process Can Be Complicated – No matter how they are constructed, all projects must meet federal, state and local laws and codes. However, the codes that are applicable change based on method.
- Risk is on Few Suppliers – Modular manufacturers have mostly focused on making single-family homes as their bread-and-butter products. While the number of companies producing commercial and multi-family products is growing.
- Transportation Costs & Risk – Since modules are prefabricated in a factory miles from the job site, they need to be transported either directly to the job site or staged at a place nearby and then set in place.
For contractors, it’s an opportunity to reduce risk and deliver budget and schedule certainty to clients while increased safety to workers. The first steps toward incorporating prefabrication into projects are to educate teams on the offsite spectrum and begin evaluating solutions that may make sense for upcoming projects.
Prefabricated homes, often referred to as prefab homes or simply prefabs, are types of prefabricated building, which are manufactured off-site in advance, usually in standard sections that can be easily shipped and assembled. Some current prefab home designs include architectural details inspired by futurist architecture.
- Modular homes are created in sections, and then transported to the home site for construction and installation.
- Manufactured homes are built onto steel beams, and are transported in complete sections to the home site, where they are assembled. Wheels, hitch and axles are removed on site when the home is placed on a permanent foundation.
- Mobile homes, or trailers, are built on wheels, and can be pulled by a vehicle. They are considered to be personal property, and are licensed by the Dept. of Motor Vehicles.
Sources: technologycards.net; realprojectives.com; constructionexec.com