Off-site construction or prefabrication is becoming more pervasive across various sectors of the construction industry, and it isn’t any wonder why. It delivers tremendous advantages to all stakeholders –– owners, architects, contractors –– across the planning, design-build workflow and construction value chain by significantly improving the efficiency in the construction process.
Benefits of off-site construction
Over the years, construction has faced its fair share of complexities. We are being challenged to do more with less –– less time, less money, less labor, less land, etc.
The growing national trade labor shortage is putting an additional strain on the construction process because there is less skilled labor responsible for building more complex projects. Additionally, the current stress on logistics and material supply changes is making cost predictability more complex.
Off-site construction directly addresses each of these challenges and has several other ancillary benefits:
Reduced time and cost: Adherence to project schedule and budget are among the two most looked at metrics in construction. Prefabrication and off-site manufacturing not only brings greater predictability to both, it also improves performance. In some cases, we’re seeing prefabrication reduce labor and material expenses up to 14% on a single project. And according to the “Prefabrication and Modular Construction 2020” report, more than 40% of general and trade contractors surveyed cited better than 10% schedule compression.
A number of factors contribute to schedule compression, but the primary driver is the ability to run multiple processes or construction sequences in parallel with one another rather than subcontractors having to wait for portions of the project to be completed before they begin their work. For instance, site preparation can be underway as various assemblies like MEP racks and risers are simultaneously being built offsite.
Enhanced productivity: Prefabrication enables contractors to work on labor-intensive parts of the project before the job site is available, enabling hours of work to be completed on their schedule and in a controlled environment. Complete or near-complete assemblies can then be delivered to the site and installed much quicker.
When cloud-based technology and BIM processes are involved, it also enables teams across the design-build to communicate updates in near real time. It’s all too common for changes to be made on plans that are already in progress as job site conditions change or delays in the supply chain occur. These changes can automatically be sent to various teams or even to estimating software to improve cost and schedule predictability.
Reduced waste: With off-site manufacturing, there is simply less waste generated than with conventional stick-built approaches. Waste can be designed out of the process and materials managed prior to leaving the factory rather than diverting it after the fact. By improving the quality, reducing site errors and rework, the amount of waste generated is decreased considerably. In some cases, it can also bring new meaning to the term “adaptable reuse” as components or entire buildings can be deconstructed (taken apart much the same way they went together) for use in another application.
Improved safety, reduced risk and limited job site density: Transferring some of the work offsite reduces the number of people needed on the site, which also reduces the number of vehicles and overall congestion which improves safety. It also moves work to a more controlled environment where workers aren’t exposed to weather extremes and other dangerous conditions.
Offsets the trade labor shortage: Skilled tradespeople across the MEP landscape, and beyond, are becoming more scarce. This is happening globally, but can present a bigger challenge depending on the location of the building (some regions are more impacted than others). Prefabrication allows construction teams to choose to manufacture building elements in areas where there is more readily available and specialized labor.
Improved quality assurance: With prefabrication, assemblies can be tested before they’re shipped to the site. Additionally, one of the primary advantages is work is conducted in a controlled environment, not subject to inclement weather and usually with standardized production methods. When modules arrive at the site, pre-tested and inspected for quality, it also reduces the amount of rework.
As the construction industry faces a paradigm shift, with everyone across the construction value chain being held more accountable to cost, schedule and quality predictability and performance, those who embrace off-site construction and tech-driven workflows will be positioned to thrive in the future.