Overcoming the building challenge pt. 1

In this new article series, Sam Andras, founder of MJ12 Design Studio, takes us on a journey to better understand the challenges of selecting a structure for setting up a large-scale cannabis cultivation. The elements to take into consideration when choosing a building for a cannabis grow are many, and relying on an expert gives huge peace of mind. Whether it’s a new or an existing building, Sam knows what to do, and in this article series, he helps us to better understand the complexity of cannabis growing structures. 

A vast majority of those entering the cannabis industry look to develop their startup facility by purchasing an existing building for fit out. This is driven by a number of different factors which include: states whose requirements stipulate a quick operational timeline from the date of award, a lower cost of initial development, and an eased site planning and stormwater process. Each of these are very valid considerations.  At the same time, there are several considerations beyond the above that every owner should include on a facility checklist when considering an existing building. These include: the ability of the existing building to house the desired program (spaces) in a functional manner, the clear height of the facility as related to the desired cultivation methodology, the structural capabilities of the existing system, the condition of the existing building, the insulation value of walls and roof and it’s conformance to any state energy codes, parking, access road and traffic, distance from restricted zones and/or building uses, and the availability and quality of utilities.

Each of the above considerations differ greatly by building type and location. The location factor is an across the board consideration.  The parking, access road and traffic, distance from restricted zones and/or building uses, and the availability and quality of utilities must be considered on every site.  Not investigating site conditions prior to making a purchase can leave owners with an unusable facility.  Considerations with parking include the site’s ability to support the proper number of spaces based on local parking/zoning regulations while also allowing for shipping and receiving traffic. Access roads and traffic are a consideration when the local municipality requires traffic studies and the development’s impact as a consideration for project approval.  Roads must also be considered based on the type of delivery vehicles anticipated to support operations.  Every state has restrictions on site distance from schools and other similar building types. Ensuring the proper distance from these restricted facilities is key. Finally, the availability and quality of utilities is also extremely important. On more than one occasion we’ve had a owner present a site for development only to be told by the power company the required megawatts wouldn’t be available for several years, if at all, or only sooner for a hefty fee. The quality of the utilities is equally important. Power outages on a regular basis are detrimental to any cannabis operation.  Water pressure and quality should be investigated to formulate an understanding of system needs within the building. Discussing waste water, condensate and grey water, with the jurisdictional authority will provide valuable information for determination of required building components for each system.

When considering building type, there are generally three types of buildings cannabis owners focus on. These are pre-engineered metal buildings, conventional steel buildings, and heavy timber historic mill buildings. Each come with their own unique challenges as related to the cannabis industry.

Pre-Engineered Metal Buildings (PEMB)
These buildings are usually single story with fairly open bay spacing.  Most have an eave height over fourteen feet, though some may be as low as twelve feet. PEMB’s usually are rectangular in plan with 25’ or 30’ bay spacing and sixty feet or more wide. These facilities typically work well as related to the functional layout of space. Where these buildings generally have issues as related to the cannabis industry are roof/wall panel system, insulation value, structural capabilities, and airtightness.

Generally, a PEMB is selected for initial construction based on the low cost of development. The cost is low because the system is extremely basic. The typical PEMB will have corrugated siding with a standing seam metal roof. However, some lower cost buildings may include corrugated roofing in lieu of the standing seam. This lower grade roofing is more prone to leaks and failures. Standard PEMBs have vinyl faced insulation, also called bag insulation, which typically provides an R-value of 19 at the roof and 13 at walls. Most energy codes now require an R-30 on roofs. Additionally, a higher R-value for roof insulation on a cannabis facility is a plus as it will help keep operational costs lower. Adding to the complexity, the roof and wall panels of a standard PEMB are not designed to control air and/or insect infiltration.

Lastly, the structural capacity of a standard PEMB must be considered. PEMB systems are designed with the minimal amount of steel required to meet code. Generally, there is a 2 lb / sf additional capacity of the roof purlin system. This means only 2 lbs / sf of additional load can be added to the existing roof structure. To put this in perspective, if utilizing a 3” insulated metal panel ceiling suspended from the structure with ceiling suspended HPS lighting, ductwork, sprinklers, and fans the load is about 12 lbs / sf. Further, rooftop mechanical equipment is out of the question. 

Structural issues can be addressed with some innovative engineering and added cost. However, the result could be additional columns in the building, impeding clear spans and requiring foundation work.  Addressing the insulation can be done with add-on systems such as “Simple Saver” or similar applications.  In fact, some states address R-values by including language specifically tailored to PEMBs.  Massachusetts for example states roof insulation can be a combination of R-19 over the roof purlins with an additional R-11 attached to the underside, thereby a total of R-30.

Comparing a typical existing PEMB with one designed specifically for cannabis illustrates the differences in systems. When designing a new PEMB for the cannabis industry, our team will recommend the use of insulated metal wall and roof panels. The roof panel comes in a standing seam option and an R-value of 30 is easily achieved while the walls are generally specified to an R-23, thereby a roof and wall design meeting energy codes. Further, the use of insulated metal wall panel ensures a higher level of indoor air quality while also helping to address odor mitigation. Prior to ordering the building, the team will define all loads to be carried by the building including rooftop mechanical equipment, ceilings, and ceiling/structure supported systems. These loads are then built into the PEMB design.

Stay tuned for the second part!