A multitenant, leasable warehouse space in Springfield, Missouri, boasts a total of 3.2 million square feet. Known as the Springfield Underground, the warehouse is situated within the hollowed-out chambers of an old limestone mine. Spaces are available with 30-foot ceiling height options, including fire sprinklers. About 500 to 600 tractor-trailers drive through the structure every day, and a railroad service runs down the middle if your cargo arrives or departs by train.

However, before you sign the lease paperwork, there is one catch: The warehouse is in a cave. 

If you ask your coworkers for their thoughts about moving office space from their current desks into a cave, what would they say? They might prefer an office with floor-to-ceiling glass in a tower — the popular choice among most builders and property owners. As high-performance building expert Robert Bean often notes, modern construction sometimes looks like an architect was tasked with building a supersized radiator. 

If you were an engineer tasked with dissipating heat, you would select a 100-story tower in a cold climate to do it the quickest. However, that is the type of commercial space many people desire, so architects will keep designing them and builders will build them. 

Aboveground glass structures are desirable for people but not necessarily for climate-controlled storage and manufacturing. Caves are ideal for areas needing to be cool in the summer and warm in the winter without suffering high utility bills or variability of working conditions.

The structure of the Springfield Underground is unique because it wasn’t built to be a warehouse — it is the void left by mining operations. Imagine an ant colony built on a grid system with big square rooms in a more than 5-mile-long piece of gravel. 

Cave State

Missouri is the Cave State, so the Springfield Underground isn’t the only building like this. Outside Kansas City is another cave warehouse complex, called SubTropolis. According to its website, 42 Arrowhead Stadiums (home to the NFL’s Kansas City Chiefs) could fit inside. Only a little more than half of the rock formation has been mined, so another 6 million square feet or more of space is still to be developed.

You’ll find significant and rare items throughout the 10-plus miles of roads connecting the SubTropolis and within the tenants’ spaces. Metro news notes that items stored in this underground complex range from tax records and federal court documents from the National Archives and Records Association to the original film reels of “Gone with the Wind” and “The Wizard of Oz.” Storing these important items in a climate-controlled facility contributes to their preservation. 

Both warehouse facilities attract food and drug manufacturers because the temperature is so stable. SubTropolis is the home of an assembly line for pickup trucks where they apply the spray in bed liners because the conditions are the same every day of the year, enhancing quality control.

The underground warehouse attracts another set of resiliency-focused customers looking to protect critical infrastructure and record storage. Having lived in Missouri for more than a decade, I can attest that the spring and summer storms can be very destructive. The cave warehouses are additionally interesting to critical computer server banks in the tornado alley of the Midwest. 

Redditt is the source of many wild rumors about what is happening in the Springfield Underground. However, it isn’t that secretive, considering a 5K running race was held there in 2014. I attended a presentation by the local utility company in one of the chambers in high school. 

Right Temperature

From a PHCP audience standpoint, why are these buildings so interesting? A cave is an excellent building envelope. According to its website: “The Springfield Underground has a constant ambient temperature of 62 F … Dry buildings can be humidity- and temperature-controlled. Refrigerated buildings range from -20 F to 55 F and are cooled by ammonia refrigeration systems.” 

This is an excellent set of features to keep eggs at the right storage temperature; however, the overall cost savings compared to a metal warehouse baking in the Missouri sun all summer is the major draw. “The thermal mass provided by the limestone, energy-efficient building construction and cool ambient temperature all combine to decrease our customers’ utility consumption by 30 to 50 percent,” the site reports. 

You can watch a video tour of the Springfield Underground facility at Ozarks First and learn more about the train integration, including a spur directly to a big Kraft cheese factory nearby. It explains the additional logistics and fuel savings afforded by a train essentially pulling directly into the refrigerator. 

How efficient are these cave warehouses in comparison to other similar facilities? The energy efficiency of SubTropolis in Kansas City was quantified in 2012, receiving a building Energy Star score of 100 (the scale goes from 1 to 100). The owners joke that they have The World’s Largest Green Roof. 

It wouldn’t make sense to dig a cave for extra warehouse space across the locations where our PHCP products are housed. Copper pipe isn’t as temperature-sensitive as cheese. However, it is a common target for thieves if a chain link fence or an aluminum siding building is the only thing keeping them apart. 

Is a cave commute right for you? It depends on the tasks you do in a day. If you are writing the check for the monthly energy bill in a traditional warehouse, the concept of reducing your utility bills by 50 percent is alluring. No need to put on a new roof or another coat of paint in a cave, so the maintenance costs could also decrease. The earliest records we have of humans are in caves, so something is working well down there. 

I have not started a real estate business that leases space in caves. While I’ve been hitting the upsides of the subterranean work life hard in this column, I realize this won’t be for every business or occupant. At a minimum, these two caves in Missouri are excellent case studies of working with the local geography to reduce the climate and security variables affecting business owners. 

Those who have picked the cave storage option may be laughing all the way to the bank by reducing the traditional maintenance and operation costs associated with a slab-on-grade building. It would be hard to tell since the 150 feet of solid rock muffles sound pretty well.