Rack supported buildings that integrate automated storage and retrieval (AS/RS) systems offer a range of benefits to distribution operations. Although a rack supported building’s design does not enable future reconfiguration should the operation’s intended use change, for a fully automated operation it can deliver several advantages. Integrating structural racks directly into the building’s framework allows facility operators to maximize storage density while reducing construction costs. There are, however, several key design considerations a rack engineer must account for when designing the system plans.
What is a Rack Supported Building?
With a rack supported building, the rack designer is required to incorporate wall girts, roof purlins, and ancillary framing within the racking structure. These features support the wall and roof cladding. RMI’s ANSI MHI16.1: Design, Testing, and Utilization of Industrial Storage Racks standard notes that the rack’s design must accommodate not only the normal storage rack loads, but also must withstand environmental loads. These include wind, snow, rain, roof live loads, and seismic loads as applicable.
“Designing the storage bays as a rack supported building takes essentially the same amount of time as designing the storage bays for a system installed independently of the building envelope,” said Arlin Keck, Principal Engineer at Steel King Industries, a member of the Rack Manufacturers Institute (RMI).
“However, a rack supported building’s design, especially one that integrates an AS/RS, must incorporate a host of other structural elements,” he continued. “The primary goal of the racking system is to optimize all the integrator’s equipment used throughout the entire handling system. Therefore, it takes longer to complete than a standalone rack design.”
Keck noted that this extended timeframe holds true regardless of the type of AS/RS planned. That includes automation incorporating crane-based unit-load (pallets) or mini-load (totes) placement and extraction. It also applies to systems featuring shuttle-based storage and retrieval.
The Benefits of Rack Supported Buildings and Automation
Companies undertaking greenfield construction to accommodate an AS/RS can attain several benefits from integrating the rack structure into the facility. Among them are:
1. Space Efficiency
Integrating racks into the building structure allows for full utilization of the height of the building. This enables higher storage capacity. It also eliminates the need for separate structural columns, reducing wasted space and enabling denser storage configurations.
2. Cost Savings
Higher storage density reduces the land footprint needed for the facility. Further, designing the racks as a building structure requires fewer steel beams and columns, cutting construction material costs.
3. Streamlined Automation Integration
The integrated design optimizes the entire system, from receiving dock to outbound shipping. By connecting all material handling technologies, including conveyors that feed the AS/RS, automated picking and sorting systems, and more, rack supported buildings design can reduce transportation time, increasing throughput.
4. Energy Efficiency
Due to their more condensed footprint, rack supported buildings can be less expensive to heat, cool, or maintain at specific temperatures. Additionally, because AS/RS often operate in low-light conditions, rack supported buildings reduce the need for extensive lighting. Both of these factors contribute to lower energy consumption and carbon emissions.
5. Shorter Construction Timelines
Compared to conventional buildings with separate racking systems, integrating rack into the facility’s structure speeds up construction and commissioning.
Design Must Consider Multiple Factors
A rack supported building’s design and construction must conform to all applicable building codes, Keck added. These include the International Code Council’s International Building Code (IBC), used by the majority of state, county, and local governing bodies in the U.S. The IBC references ANSI MHI16.1 as the standard for safe design and installation of steel storage racks.
Not only does the rack design need to accommodate the specifications of the loads stored within it, but also it must account for the building’s mechanical systems. Among them are heating and ventilation duct work, lighting, sprinkler system, electrical conduit, lighting, insulation, plumbing, and more. With automated systems in particular, it’s important to design access areas throughout the racking for routine maintenance.
“Because the rack design needs to account for the building loads attached to the storage system, it needs special anchoring and larger, heavier uprights,” he said.
Additionally, the concrete floor slab must be thick enough to support the high roof heights that often accompany AS/RS. Likewise, the soil beneath the slab must be able to bear the load of the building and its contents.
“The higher the ceiling, the thicker the slab-on-grade needs to be,” Keck added. “These systems sometimes hold more than 50,000 pounds in each bay. A 120-foot-tall double-wide by double-deep unit-load bay may need to support 150,000 pounds, for example. Therefore, the engineer designing a rack supported building must verify that the soil and concrete slab-on-grade can withstand the forces applied.”
Who Should Design a Rack Supported Building?
In general, designing a rack supported building requires an engineer with more experience designing both rack systems and facility structures. Keck explained that’s because the engineer must be able to visualize the entire operation as an integrated whole.
“The rack engineer also has to have a basic understanding of all the different types of equipment planned for the facility,” he noted. “It’s important to understand how the different systems will interface with each other and the rack. Depending on the type of AS/RS, there will be different operational tolerance requirements in order for the automation to function properly.”
For that reason, a high degree of quality control is critical to the design and construction of rack supported buildings integrating automation. “Also, all the systems and components have to fit together both within the building and attached to the outside of the building,” concluded Keck. “That makes quality control essential.”
Get More Information About Integrating Rack and Automation
RMI recently presented “Pallet Racking Systems and Design for an Automated Future” at ProMat 2025. The seminar explores key design factors that enable rack to successfully integrate with automated systems. A recording is available.
