While sustainability in data center operations has long been an industry focus, sustainable data center construction is anticipated to play a larger role in achieving the near-term 2030 goals set by the Paris Agreement.

General contractors are the crux of the construction industry. They directly affect the energy, water, and waste footprint of construction projects and indirectly contribute to the health and well-being of the building’s future occupants. The energy power (megawatts) required to run data centers increased 34% in the last 6 years in primary North American markets. As the need for data centers increases, GCs will play a key role in building them sustainably. Here is where GCs should focus those efforts.

The first step to making a project more sustainable is to understand its environmental footprint. This takes the form of construction energy, water, and waste tracking and analysis. Working with the project team, GCs can ensure that metering is set up at an appropriate time to capture all of the resource use necessary to achieve the team’s sustainability goals. Having a dedicated on-site sustainability champion on the GC team (ideally someone with their LEED AP or LEED GA credential) to collect and report this data is integral to ensuring accuracy and consistency in the process. The GC sustainability champion should work with the owner’s representative to establish project sustainability goals and agree on a data reporting cadence to track progress toward these goals.

The GC can help work with the design team to establish these goals through integrating the following best practices for resource use in data center construction. These can help GCs execute on quality data gathering and reporting with the owner’s representative:

• Set Contractual obligations for data reporting
• Establish a sustainability champion on site and within the owner’s rep
• Establish a reporting cadence and clearly identify data sources
• QA/QC data with owner’s rep

And how can GCs help set these goals? Many GCs assume that their sustainability impacts are constrained by the project requirements, but there is significant opportunity to reduce resource use while still delivering on the project as designed.

Data centers’ often remote locations and size tend to result in a massive amount of construction energy use, especially for construction equipment and generators that primarily use diesel, which has a much higher carbon footprint than electricity in most regions. This makes electrification of construction equipment and generators an attractive opportunity for reducing carbon emissions of data center construction.

GCs should work to select an equipment provider with access to hybrid, electric, or even solar-powered equipment, if available within the region. Where electric equipment is not available, consider adding a battery pack to an existing diesel generator to reduce run time and decrease the amount of diesel used.

There are a few barriers to adoption that could come with a switch to electric equipment. The first is availability of equipment, which can be difficult to procure in some regions. It is expected that supply will catch up as regulations evolve and developers begin to demand this equipment to hit their net zero targets.

A second perceived barrier to adoption could be equipment familiarity and safety. Many operators feel more comfortable using equipment they are familiar with. The diesel drone that some are so familiar contributes to whole-body sustained vibrations which can have an adverse impact on operator energy and could contribute to operator fatigue. Switching to electric equipment reduces the fatigue imposed on the body from the operation of diesel-powered equipment. Additionally, the use of electric equipment improves the air quality of the job site by limiting the amount of diesel-powered equipment on site.

Equipment and generator electrification is integral to helping projects achieve their carbon emissions targets, as well as improve operator health and well-being and construction site air quality.

Water use in the construction of data centers has increasingly become an area of focus for GCs due to large uses in dust mitigation and soil conditioning needs. GCs can alleviate the impact that construction activity has on potable water use by using reclaimed water from the utility and/or the site, where available.

If the local utility does not provide access to reclaimed water, GCs can establish an on-site water collection pond and/or purchase equipment that recycles water internally, like a tire wash station. Other opportunities for reducing water use can be found in the Practice Standards and Specifications for Construction Dust Control.

The United States generates 600 million tons of construction and demolition waste annually. A construction and Demolition Waste Management Plan, including anticipated waste material streams at the site and a plan for the disposal or diversion from landfill, is integral in reducing the amount of waste from the construction of a data center.

A large opportunity for on-site reuse of materials in data construction is the reuse of concrete for gravel or new concrete. Sometimes regionally constrained, GCs should work with project teams to identify the regional capabilities of recyclable materials to inform the project’s waste diversion practices.

Clearly define and communicate the project's waste diversion goals to ensure they are met. Appropriate training as well as posting clear signage and direction to the recyclability of materials is key to success.

The energy use and emissions associated with the actual construction process isn’t the only way construction contributes to carbon emissions. Embodied carbon includes all the carbon emissions associated with the materials used in constructing the building. Building developers are beginning to look at quantifying and reducing their embodied carbon by selecting more low carbon materials.

Tools that GCs can use to evaluate the different embodied carbon impacts of construction materials include CINARK’s Construction Material Pyramid, which sorts materials in ranked order based on carbon content and intensity and Building Transparency’s Embodied Carbon in Construction Calculator (EC3) Tool, which compares the carbon footprints of specific products. There are even some materials that can be carbon negative such as sustainably sourced (e.g., FSC-certified) mass timber.

Where the use of mass timber is not possible, GCs should make every effort to reduce the carbon emissions associated with typical structural building materials such as steel and concrete. Cement contributes 80-90% to concrete’s carbon footprint, even though it only accounts for 10% of the concrete mix. GCs should consider using lower carbon Portland Limestone Cement and/or concrete mixes with a high SCM (Supplementary Cementitious Materials) content. Slag, fly ash, or recycled glass are examples of SCMs that can replace a portion of the cement content without affecting concrete performance. Additionally, GCs should recommend sourcing steel with a recycled content of 75% or higher.

In cases where lower carbon options result in an increased cost, GCs must be prepared to communicate the added benefits of a lower carbon footprint as they relate to the project team’s sustainability goals.

Incorporating these strategies into data center construction projects will improve environmental performance and can lead to indirect positive impacts on the project’s goals such as tracking toward a building certification like LEED for Data Centers or improving the health and well-being of occupants. In the world of data center construction, there’s ample room for sustainability and GCs play an integral role in its success.Jess Pearson seeks to deliver strategic solutions that consider social, environmental, and economic impacts in every project at Stok. You can contact her at jess@stok.com.

Paula Przybylski is a sustainability consultant at Stok, managing projects involving carbon accounting, healthy materials, and green building certification. You can contact her at paula@stok.com.