There is growing recognition today that prefabrication represents an opportunity to transform the construction industry. By moving from onsite construction to industrialized construction, projects can benefit from improved safety, productivity and predictability.

When we picture prefabrication in action, we often visualize whole modules of apartments or hotel rooms manufactured at scale and slotted into place in the span of several hours — and this purported image can make widespread adoption seem a long way off.

In actuality, one group of subcontractors is already leading the way in prefabrication, virtually behind the scenes: mechanical, electrical and plumbing (MEP) subcontractors, who have been scaling their prefabrication capabilities faster than most other stakeholders in the construction ecosystem.

It’s time to recognize the achievements of MEP subcontractors — and help other subcontractors, general contractors, designers and owners follow their lead into the world of industrialized construction.

Innovation Behind the Wall

Over the last twenty years, MEP subcontractors have evolved and invested in prefabrication processes and facilities. These subcontractors are realizing benefits, and a quiet revolution is cementing both single-trade and multi-trade prefabrication as established standard practice.

A recent study showed that two-thirds of general contractors and three-quarters of subcontractors have experience with MEP-oriented multi-trade assemblies. The trend is most prominent in projects where a large proportion of the value lies in MEP trades, such as healthcare, data centers, industrial and manufacturing. The dollar value of MEP in these projects, along with the complexity of design, makes the projects optimal candidates for prefabrication and industrialized construction.

Because Design for Manufacturing and Assembly (DfMA) principles that enable prefabrication in the design process aren’t always enabled by architects and engineers, subcontractors have retained the majority of the value from implementing prefabrication as means and methods. Faith Technologies, for example, now offers a catalog of electrical assemblies, while Crown House in the UK has productized its mechanical offerings.

These MEP subcontractors (now turned manufacturers) and others continue to pursue industrialized construction trends, investing in technologies like automation and robotics to further optimize production — and continue to subtly drive innovation in the industry.

Following in the Super-Subs’ Footsteps

MEP subcontractors — especially the ones who have integrated multi-trade and applied manufacturing techniques — have proved out the significant promises and advantages that DfMA and prefabrication offer for owners and the design, construction and manufacturing industries at-large. Manufacturing in a controlled environment away from the site can increase productivity, overcome labor shortages and increase the predictability of the cost and schedule. Clients benefit from certainty, which in many cases is more valuable than savings. Meanwhile, subcontractors have long-standing and mutually-beneficial relationships with contractors — unlike a newly formed prefabrication product manufacturer, which may have limited history and fewer relationships in the industry.

Critically, prefabrication enables subcontractors to be product-led, rather than project-centric. The manufacturing business model involves optimizing the production of components over time, rather than continually adjusting to meet the needs of a single project. Subcontractors can spread capital investments across multiple projects and use data to continually refine their products and process.

Subcontractors of every trade should consider adopting prefabrication, rather than waiting for manufacturing specialists to apply the approach to the construction sector. Subcontractors have the advantage of already understanding the industry and having built trusted relationships with owners, architects and general contractors.

MEP subcontractors have led the way; now, other trades have the opportunity to benefit too.

Another category of subcontractors embracing industrialized construction is those focused on structural assemblies, such as light-gauge timber framing systems and precast concrete. There are significant opportunities for these firms as they deliver chassis for other prefabricated assemblies and modules.

The Road to Industrialized Construction

Designers and contractors looking to adopt DfMA and prefabrication can draw useful lessons from the experiences of MEP subcontractors and what they have already achieved.

Embrace the Manufacturing Mindset

Going from project-centric to product-led construction

The most important starting point is to shift from a “project-centric” mindset towards a “product-led” business model. Subcontractors have historically adapted their prefabrication services for individual projects, creating custom one-offs which only provide limited benefits. However with a product-led approach, the most successful firms will create a set of standard prefabricated products that are clearly defined, managed and ultimately optimized.

For example, prefabricated products may include multi-trade distribution racks or risers, electrical or mechanical plant rooms and medical headwalls. Stay with your optimal product designs and resist the urge to customize every time. If you do find yourself consistently customizing, you might not have the correct product, or you may not be explaining how the ease of manufacturing (the “dfm” of DfMA) adds value to your standard product. A good indicator is if your standard product is optimized with your production process, resulting in lower costs and shorter lead times.

Establish Closer Collaboration

Adopting prefabrication also changes how subcontractors collaborate with the stakeholders of the design, build, and operate ecosystem. Prefabrication needs to be enabled at project conception and remain the focus throughout the design, procurement and building processes. Best case scenario: learning has been incorporated before a project exists at the enterprise level of participating companies and driven by owners who understand expectations and collaborate to remove risk with their partners.

In addition to developing the prefabrication strategy based on product, itself, it’s important for subcontractors to outline how others need to design and assemble these elements by educating them on the specific DfMA principles for each element. Element-specific DfMA is a particular set of instructions that apply to one type of element and include the proprietary rules of each manufacturer because, at this point in time, there are few standards. They outline the design choices that need to be made for ease of manufacturing and ease of assembly for the prefabricated element.

Engaging with clients, designers and general contractors is critical to ensure that prefabrication delivers on its potential for the project. When using prefabricated elements for the first time, general contractors can fall into the trap of ordering highly customized products — which may be significantly more expensive than standard prefabricated parts with similar performance, and based on the production methodologies and supply chain partners supporting the fabrication facility.

Collaborating early on can avoid these kinds of errors and help clients, designers and contractors to identify the prefabricated elements that are the best fit for the project. Utilizing digital technology and building information modeling connected to a construction platform helps subcontractors to communicate and share information throughout the project lifecycle. Information sharing and transparency, from the creation of design through to operations is more transparent using collaboration platforms.

The Importance of Optimization

Finally, the early adopters of prefabrication have also highlighted the importance of optimization. Once a product is defined, engage in a continual process of improvement, including investing in new manufacturing technologies like automation and robotics fabricators that are able to draw on data for analysis. This analysis enables future certainty of cost, schedules and quality using these prefabricated elements in the future.

It’s important to remember that industrialized construction isn’t just moving to a controlled off-site environment; it’s also about applying manufacturing techniques. With ongoing improvements to the fabrication process, product portfolio and workflows, subcontractors can deliver on the full potential of prefabrication — benefiting themselves, and the rest of the industry, in the process.

The Unsung Heroes of Prefabrication

Subcontractors in the mechanical, engineering and plumbing trades have quietly driven significant transformation in construction. And although much of this innovation sits “behind the wall,” these trailblazers have already proven that embracing prefabrication can not only deliver benefits for everyone in the construction lifecycle, but also generate value and increased profit for their own companies.

Subcontractors should look to embrace prefabrication, as they can benefit from greater predictability, productivity and profitability as a result. MEP subcontractors have shown us the way. Now it’s time for others to start their own journey.

Amy Marks is head of industrialized construction and evangelism at Autodesk. Previously, she was the CEO and Founder of prefabrication startup XSite Modular and she advised Singapore's government on industrialized construction.