Data Center Structural Design: Understanding Live Load Requirements

by Dipl. Ing. Daniel Bacon

In the world of hyperscale and high-density facilities, structural safety and load planning are fundamental to reliable data center performance. While cooling, electrical systems and IT equipment often receive the spotlight, the structural backbone is what ensures that a data center can safely support heavy racks, cable routes, suspended installations and future upgrades.

Understanding live load requirements is one of the most critical aspects of designing any data center. Incorrect assumptions can lead to oversized structures, costly redesigns, or worse, performance and safety risks. This article breaks down the technical principles behind data center live loads and explains how structural engineers, including the specialists at gbc engineers, approach this essential part of early-stage planning.

What is a live load? 

A live load is a variable or movable load that can be present, partially present or not present during the lifetime of a structure. Engineers simplify this by assuming the load is either present or not present in a certain area of the structure. A live load in a datacenter could be the server rack standing on top of the slab or the pipes and cables hanging on the bottom of the slab. 

Live loads hanging on the bottom of a slab or sitting on top of a slab - Why is it important? 

Live loads hanging on the bottom of a structural member need to be treated differently in the analysis as live loads on top of a member. For reinforced concrete members the load on the bottom needs to be “hanged up” by additional reinforcement in the concrete member. Although the impact is usually small in normal cases, this is a topic to be addressed for clear and clean definition of requirements. 

What types of live loads (acc. to Eurocode) are there and why is this important? 

Live loads are separated into types such as residential, office, congregation areas, shopping areas, storage areas, wind, snow, etc. There are basically two main reasons why defining the load types correctly is important for a safe and economic design. 

Reason No. 1  

When calculating a structural member, we (structural engineers) combine the different live loads acting on that structural member based on certain rules. These rules define the probability of two or more live loads acting fully at the same time.  

For Example:  
Let’s assume we have wind and live load on a roof. Is it plausible that when we have a storm the full snow load is also present on that roof? The answer is no. Wind or snow load will be reduced when combining both loads, allowing more economic designs. 

Reason No. 2 

Deflection limitation requirements are often a dominating design criterion and therefore affect the economy of the structure. Different types of live loads and live load combinations will cause different magnitudes of long-term deflections. Why? This lies in the specific behavior (creep and shrink) of reinforced concrete members. Think of it as if you were holding weights above your head. For a short time, you might be able to hold the weight up high but over time your arms will give way a little. What counts for the long-term deflections is the amount of live load which we assume will be present on the structure over the life span of the structure. As structural engineers we would assume that around 30% of the total live load would be constantly present in a residential building while for a storage facility we would assume that 80% of the live load would be present over the life span of the building. This means the impact on the long-term deflections of a slab under storage load will be approx. 2,7x higher than under residential loading. 

Is the load of the server rack equal to the live load? 

The simple answer is NO. When determining the live load on a structure we are commonly referring to the load distributed on the entire area of a span (area between columns or walls). To determine this area live load, you must ask yourself the following question: “Which area live load distributed on the entire area of the span causes the same stresses in the structure as the actual loads from the racks?” As you see by this question, the layout of the racks plays a role in the determination of the live load.  Lets look at the example below: 

Example: Determination of Area Live Load for DC Span

Figure 1: Layout of Typical DC Hall

Results Representation

Conclusion

In this example, the rack live load was calculated as 20.83 kN/m². However, the structural comparison shows that an equivalent uniform live load of 10.2 kN/m² produces the same internal forces in the slab system when the actual rack layout is considered. This demonstrates how strongly the definition of live load influences both the structural behavior and the overall economy of the design.

Accurately determining the required area live load is therefore essential. While this example uses a simplified approach, real projects must also consider future flexibility, equipment changes, and long-term operational demands.

gbc engineers supports data center developers with a precise structural analysis methodology that converts real rack layouts into reliable design loads. This ensures optimized construction costs, improved structural performance and long-term resilience, key factors for any high-density or hyperscale data center project.