An old colleague once remarked that if cars were designed like traditional commercial buildings, every car would still look like a 1970’s Cadillac. Car hoods would need to be three times their current size to accommodate dedicated sections for heating, cooling, powertrain, electronics, etc.— and the buffers between them. While the observation was intended to be humorous, it held a nugget of truth: the rigidly segmented approach commonly used in building design and construction can create space inefficiency and other unforeseen consequences.

That isn’t to say there aren’t good reasons for the way the engineering and construction industry currently operates. Building a complex, custom facility creates challenges that impact all stakeholders on a project. Solving these challenges has traditionally required the specialized skills of multiple, separate trades. To reduce the complexity of those trades working in the same space, discrete construction areas are traditionally designated for each trade—the ‘sandboxes’ or ‘no-fly zones’ many of us are used to seeing. A side benefit of these “zones” and extra space, as discussed in my last piece, is that they can deliver operational efficiency and repairability benefits for those projects that can afford it.

As we know in construction, however, one size does not fit all. There are good reasons, based on the scope of the project undertaken, for rethinking whether the traditional single-trade, parallel approach makes sense, or whether a multi-trade modular approach might be a better fit.

Why Multi-Trade?

1. Space constraints.
   The most obvious drivers behind taking a multi-trade approach are the physical constraints limiting the space available for each functional element and associated trade. One constraint of modular construction is the need to design for transportability. Whether you have chosen to utilize a skid-based approach or have opted to build volumetric modules, the project’s building blocks must meet certain size constraints for delivery to the installation site. Utilizing a multi-trade approach to construction can maximize the space efficiency of the modules that are built and transported by reducing their physical size or increasing what can be shipped within each module.
   More importantly, a space-efficient build can positively impact site selection because an item with a smaller footprint can be installed on a smaller site or can allow an existing commercial space to be re-purposed instead of built new from the ground up.
   
2. Capital constraints.
   Not every project requires a full scope build-out prior to initial operation. For some data center projects, it is a much more efficient use of capital to take a phased approach by adding capacity over time, when needed. However, the need to remobilize each trade for every new follow-on phase can bring challenges in the form of time, effort and cost. Designing a project from the start with a true multi-trade modular approach can significantly reduce the number of future re-mobilizations and enable capital costs to scale in a more linear fashion as capacity is added.
   
3. Sustainability.
   Building using a modular approach significantly reduces the amount of construction waste created. Using a multi-trade modular approach can help reduce waste even more. Removing or reducing the need to wrap modules onsite, while other trades complete their tasks, eliminates a layer of unnecessary construction waste and inefficiency. In addition, as mentioned earlier, the ability of multi-trade modular coordination to open up the possibility of a re-purposed site can have an additional significant material use impacts that can improve the sustainability metrics of a project.
   
4. Standardization.
   A data center industry aspiration is to increase the level of standardization across the data center lifecycle to reduce complexity and cost. Just as groups like the Open Compute Project have made significant strides on compute and networking elements of a build, a multi-trade modular approach has the potential to unlock similar data center construction efficiencies. If you aren’t looking at a single project, but have a multi-site, multi-year program of data center projects, using standard components can significantly reduce design and construction complexity as well as shrink construction schedules.

If one or more of these elements is important to your data center program, then a multi-trade modular approach may help you reach your goals.

What’s the problem?

If modular data center construction is compelling, the reasons outlined above may make multi-trade modular sound like a guaranteed solution. So why isn’t it being used everywhere? There are three big reasons:

1. Inertia.
   One of the attractions of skid-based, single-trade modular is that it can be easily incorporated into the traditional design process. In contrast, multi-trade modular—whether skid-based or volumetric—requires a level of up-front commitment and willingness to adopt a new model that can be challenging in an industry with decades of experience doing things a certain way.
   
2. Availability.
   Until we can reach the levels of standardization the data center industry aspires to, designing and building tightly integrated multi-trade modules that deliver on their promise adds complexity, compared to traditional segmented approaches. In the meantime, it is a challenge to find design and manufacturing/construction partners who have the ability and experience to ensure designs are right the first time so that they can be easily constructed.
   
3. Mindset.
   Construction is far from the first industry to face a similar challenge. The first cars were indeed very space inefficient, with huge hoods and lots of empty space. The same is true of the first computers and cellphones. These industries and many others have solved these challenges with a concerted drive to reduce materials and space with a focused manufacturing mindset. Construction can follow the same path, but it will take a concerted shift across the industry to make it happen.

Conclusion

Multi-trade modular isn’t for everyone. In an environment where space isn’t a concern and the other factors mentioned earlier are not a priority, the challenges of taking a multi-trade approach may outweigh the benefits.

If the factors above are a significant consideration on your project, however, then multi-trade modular may be for you. The increase in effort and up-front planning involved can deliver significant benefits if you have the right design and construction/manufacturing partners with you on the journey. Focusing on your priorities should enable you to make the right choice and maximize your return.