There are currently 21 states, along with Washington, D.C., and Guam, that have acted to legalize recreational marijuana. As more states across the U.S. legalize cannabis, both the global and local sales markets continue to grow.
As legal cannabis continues to grow across the U.S., metal buildings are being used for grow facilities

The cannabis industry is growing quickly but is a volatile environment for both companies and investors. As Parker Snyder, director of business development at ARCO National Construction New England division, Framingham, Mass., explains, the cannabis industry is highly dependent upon the price of a commodity that is not allowed to be traded interstate. “As the price per gram of cannabis falls, the facilities with the least cost of production—the most efficient—will win market share.”
Types of Facilities
There are two types of cannabis facilities: grow and processing facilities. Depending on state requirements, cannabis can be grown either outdoors, in a greenhouse or in a controlled-environment indoor processing facility.
Metal building systems work well for both types of facilities, and, increasingly, metal building contractors are moving into this expanding market.
Cannabis is grown in a semi-arid environment where growers bombard the plants with light and heat to increase transpiration and accelerate the plants’ growth. The process makes the air very humid, which needs to be removed with air conditioning. Cold air must then be reheated so as to not shock the plants upon re-entering the room. As Art Hance, president, Washington, N.J.-based Hance Construction Inc., explains, the mechanical systems on grow facilities can cost nearly as much as a regular building.
The processing facility is where the extraction of various aspects of the plant such as THC or CBD happens. Some extraction methods can employ very volatile chemicals, while others do not. Hance says there are C1D1 construction parameters for facilities that rely on volatile or explosive chemicals with very technical, sealed electric systems and specialized evacuation fans.
“What makes cannabis unique begins with cultivating in an indoor facility, a controlled-environment agriculture (CEA) facility. Complexities evolve further from there,” explains Sam Andras, AIA, executive vice president of corporate business development at 2WR+Partners, an urban-gro company, Centennial, Colo. “If the facility is vertically integrated, which is a facility that includes operations beyond just cultivation, such as manufacturing and/or a dispensary, the project expands to multiple functions each with unique challenges. This is further compounded by the reality that there is no standard way to cultivate. Cultivation methodologies include drip irrigation, ebb and flow, aeroponics and aquaponics. With drip irrigation, the medium can be soil, rockwool or coco. Benching can be single or multi-tier. Temperatures and humidity levels vary from grower to grower while maintaining alignment with the vapor pressure deficit (VPD) chart.”
“Also,” he continues, “cultivation includes a wide variety of systems and equipment. This includes fertigation, water treatment and storage, benching, lighting, fans and environmental controls. Selection, design, coordination and installation of these systems can be extremely challenging.”
Project Considerations
Picking a location for a cannabis facility can be a challenge since the local community must be supportive of the project. And cannabis cultivation facilities require massive utility infrastructure compared to regular commercial or industrial buildings, Hance says. A 60,000- to 70,000-square-foot cultivation facility typically requires two to three times the electric power of a 100,000-square-foot warehouse and must be served by five times the sewer and water capacity. Security, odor control, access to workforce and transportation all are additional considerations.
“Since cannabis is a controlled, federally restricted product, there is a regulatory system in place at the state level that requires an owner-operator to already have a site selected before they can be permitted,” explains Snyder.
A metal building is well suited for indoor grow and processing facilities if properly constructed and employing the right components. By using a metal building system with insulated metal panel walls, Hance says the interior can be built right out to the exterior wall, allowing them to get dual use out of the panel. “It’s critical that people know how to design a metal building if they’re going to do that because deflection criteria become a major concern,” he adds.
“Metal buildings are a versatile and less expensive option for cannabis,” adds Snyder. “Typically, cannabis facilities require clean rooms—rooms within the exterior building shell. Therefore, the most economic shell is usually the most desirable.”
The mechanical system is the costliest component of any cultivation project. “The design of the system is tied to cultivation methodology and environmental parameters,” Andras explains. “Different types of systems have differing capabilities as related to their ability to maintain the environmental parameters. The more flatlined the environment is maintained, consistent temperature and humidity, throughout the entire room the better the quality and yields. Therefore, defining the cultivation methodology is critical to sizing mechanical while selecting the right system is critical to CapEx, OpEx and revenue.”
Metal buildings are a versatile and less expensive option for cannabis. Typically, cannabis facilities require clean rooms—rooms within the exterior building shell. Therefore, the most economic shell is usually the most desirable.
Experience is Key
Cannabis is a highly regulated industry and the approval process and permitting for new facilities can take up to a year or longer. However, since the cannabis industry is still emerging, there is not a lot of scientific data or engineering and design data that’s been published. “It’s very difficult to find the tools that most people need to design and build a facility,” Hance says. “So, it really ends up being how much experience you have in building these facilities, and what you’ve seen not work and what does work.”
However, in many respects, the cannabis industry is no different than other business sectors. “To properly develop a project, the client needs a clear vision,” Andras explains. “That vision includes needs, desires, goals, budget and schedule. It should also include expectations on revenue and operations. With this information in hand, the design team can effectively work with the client in development of a design meeting their vision. This can be accomplished through the integration and use of a proven project approach by a team experienced in the cannabis industry. The key here is experience. If the team doesn’t have experience, they won’t recognize industry specific needs.”
The cannabis industry is filled with consultants. Many, as Andras shares, offer services beyond their capabilities. “In the early years of the industry these consultants would provide full facility designs and thereby architects were seen as a means to the end,” Andras says. “Basically, architects were needed to obtain a building permit. As the industry has grown, and architects have become more familiar with the processes and methodologies of cultivation and vertically integrated operations operators have seen the value of working with those who are trained in and experienced with operational design.”
Hance Construction has been involved in the cannabis industry for four years, and Hance notes that when they were just starting out, they reached out to fellow Butler Builders and MBCEA members who were building these types of buildings in Colorado and other states where cannabis was legal. This experience allows the team to lead interested parties through the process of approvals as well as the construction side of a project, including gathering all the data needed, the watering rates, the areas for the plants and the amount of canopy needed. “All of the different factors that go into it get so complex,” Hance explains. “The design firms can only do so much, and we manage that process because you’ve got so many different entities. You’ve got an architect, mechanical engineer, civil engineer, structural engineer. You’ve got lighting consultants and irrigation consultants and all these people are supplying different systems. We act as an owners’ rep and construction manager to coordinate all this information into a cohesive package.”
If you’re interested in getting involved in the cannabis industry, Andras recommends taking the time to research team members and select based on experience, resources, capabilities and approach. “Make sure you’ve developed a vision, or work with a team that can help you with that process,” he says. “With this as your foundation, you have a great opportunity to achieve success!”