The modern data center is tasked with supporting immense systems and information, as businesses are more connected than ever before. This rapid technology evolution requires IT and facility business leaders to reevaluate their approach to data center development and deployment.

For many, prefabricated modular data centers are the answer as their predictable performance, fast deployment, flexibility, and scalability are designed to support the flood of data organizations process daily. According to a recent forecast from 451 Research, aggregate prefabricated modular (PFM) data center revenue is projected to nearly quadruple from 2013 to 2018 with the market for PFM data center products having already surpassed 1.5 billion in 2014.

In some instances of PFM implementations, the existing building infrastructures cannot support the future growth of an organization’s data, and IT and facility managers must seek new opportunities to support their advanced IT. In other instances, a business may have a “greenfield” opportunity to build without the constraints of an existing facility’s physical parameters and choose to install a PFM data center to meet the demand for flexible, on-premise data center support. Because prefabricated data center modules are comprised of a number of pre-engineered and pre-tested components including power skids and modules, cooling and hydronics modules and IT modules, these building blocks can be deployed quickly and combined to deliver increased capacity for an existing infrastructure.

The process for deploying PFM data centers, though simplified and shortened as compared to traditional data center builds, requires thoughtful planning. Project parameters such as criticality, capacity, growth planning, efficiency, density, and budget must all be determined before officially embarking on a PFM data center build. Regardless of whether a data center project is being retrofitted to meet new business needs or part of a new “greenfield” opportunity, it is necessary to ready a site for any new data center systems as a primer for success. For a prefabricated modular data center, there are several unique considerations around permits, determining the best approach for pipe and circuit installation and more before a PFM data center can be installed.

The following “dos and don’ts” for site preparation will ensure a PFM data center build sails through the “planning phase” to enable faster implementation.


Do seek permits and coordinate inspections early on.

Don’t unnecessarily task construction teams with developing detailed construction drawings.

To avoid any delays down the line, facility managers should seek building permits and coordinate inspections early on in the PFM data center implementation process. As prefabricated modules are standardized, construction drawings can be more simplified and do not need to include a detailed depiction of factory assembled internal wiring and piping. From a construction drawing standpoint, modules may be represented in the same manner as packaged generators are drawn with a focus on the field connections required.

A PFM data center approach can greatly reduce the time required to develop construction drawings and “permit sets,” as well as enable efficient review and inspection. If needed, detailed information for the PFM data center is available from the manufacturer in the form of one-line, three-line, and five-line, piping and schematic drawing files. These are also often available in multiple standard graphic formats to allow the owner or engineer to customize based on the audience reviewing them.

While inspections will generally focus on the field constructed aspects of the prefabricated data center, the inspecting authority may also require details on the materials and methods employed by a prefab vendor in manufacturing the facility module. These details are available for review from the vendor and “listed” by certifications like UL and ETL in the factory.

Since the module has technically been reviewed by sanctions like UL, the value of the facility module is usually omitted from the overall inspection and permit cost. The cost of module approvals is incorporated into the purchase price of the modules at a discounted rate, as it is spread over multiple use cases of that module type.

Do evaluate options for locating modules indoors and/or outdoors.

Don’t assume that all prefabricated data center modules are suitable for outdoor placement. 

Many modules are designed to be weather-tight enclosures that can withstand nature and are suited for outdoor installation as standalone structures. Although outdoor placement is common, it is important for facility managers to evaluate a PFM data center on an individual basis to ensure it is not limited to indoor instillation. Factors that might warrant indoor installation include:

  • The module is skid-mounted 
  • The module is an enclosure that is not weather rated 
  • It is necessary to protect personnel from inclement weather during operation and maintenance activities based on unique organization/location variables
  • Solutions may require added security for critical systems 

There are a number of benefits to PFM data centers that can be built outdoors. Organizations can see significant cost benefits, particularly if the data center applications are hosted on property that is leased.  The rental of outdoor square footage is often much less expensive than the square footage of a building and can offer the landlord an unexpected revenue stream and deepen a business relationship for both parties involved.

There are also benefits to developing sites explicitly for a modular data center build; however many companies have additional space on their office campus and an entirely new site is not necessary nor cost effective. Facility managers can work with their data center provider to retrofit these existing sites for ideal installation of PFM data centers. Key considerations when evaluating the viability of retrofitting land for data centers include the proximity and access the area will provide the modules to utilities — specifically electricity, water, and in the case of IT space modules, the “communications carriers” involved in moving the data.

Regardless of whether a business is using leased land, retrofitted land, or an entirely new area designated for a data center build, outdoor locations are uniquely suitable for utilizing medium voltage delivered from existing outdoor power distribution assets — or in the case of a new site development, directly from the utility.

In addition to access to utilities, the layout of any outdoor modules should be configured with a number of factors in mind, including:

  • Ease of module installation and removal
  • Accessibility for servicing
  • Convenience of general housekeeping, such as rain water management, snow removal and lawn, sidewalk, and lot maintenance
  • Ability to monitor perimeter security or conduct regular screening that may be required to comply with the terms and conditions of leases, or zoning regulations 

In most PFM data center builds there is also likely an existing structure that must be incorporated in planning. An existing building also serves as the “anchor” for the site and provides a permanent landmark on the site that can be associated with a recognizable street address. Additionally, the existing structure can help maintain facility requirements for a business, such as standards for a minimum number of restrooms onsite.

Do evaluate various foundational options to support modules.

Don’t underestimate the impact of weather and climate on PFM data center builds.

The site planning document for PFM data centers typically includes three overarching components: a “civil site plan,” “electrical site plan,” and a “mechanical site plan.” Foundational support for modules are an important element of site plans to support all aspects of the build. The style and type of foundation selected is often associated with the physical properties of the site, including soil conditions, surface water drainage, the presence of frost, as well as seismic and wind loading requirements for a particular geographic location. The three common types of foundations used include:

  • Continuous concrete slabs: the most common structure for placing and anchoring a module includes a 360-degree walk surface around the perimeter of the module to allow for convenient and routine onsite inspections. This foundation can also include features such as foundation walls, footings and seismic anchoring, depending on climate and soil conditions.
  • Multiple independent slabs: a variant of the continuous slab, means various smaller slabs will be used to create the foundation with gaps between slabs. Multiple slabs are frequently used when a module is surrounded by impervious cover, such as in a paved area, and there are challenges around draining surface water. Multiple independent slabs require fewer materials to construct, while still providing the necessary mass and anchoring properties.
  • Piers or columns: strong, smaller structures that may be used as a means of support when spaced to accommodate the load bearing contact points of the module. This type of foundation permits the module to be installed in areas where drainage of surface water is accomplished through leaching into the surrounding ground, rather than flowing over impervious surfaces towards drains or other surface drainage structures.

Do consider undergroundwire and piping interconnections.

The most simplified and cost effective option for supplying a data center with electricity is to run the electrical sources underground. When installed underground, feeders and circuits, along with related communications raceways, and most mechanical connections (over 40 ft long) can run more smoothly and at a lower cost for materials.

With underground interconnections, there are generally fewer support structures to be built and the opportunity to use lower cost-to-implement materials, such as PVC conduit (ideal for most underground applications) and pre-insulated pipe. Power facility modules — that can easily be fitted directly over pre-installed underground electrical conduits — can also be ordered to simplify weather sealing and conductor terminations. Additionally, chilled water piping for cooling modules may also emerge from underground directly adjacent to the module, simplifying or all together eliminating the need for support hardware or special structures.

Don’t view prefabricated modular data center builds and traditional data center builds as one in the same.

Prefabricated data center modules provide the opportunity to transform the process of data center planning and reduce the schedule and cost associated with bringing a data center from concept to completion. It is imperative that organizations understand the unique differences a PFM data center build can offer over traditional data centers — particularly as it relates to site preparation. Traditional data center builds can take significantly longer from planning to preparation and installation, and the permit process can be more cumbersome and costly. It is important to be aware of all the benefits a PFM data center can offer to avoid delays, unnecessary costs, equipment damage and/or inefficient operation. By following a few simple “do’s and don’ts” for PFM data center site preparation, organizations can quickly move into the installation phase and reap the agility and cost benefits of this data center model. n