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Ask the Cannabis Expert – Anthony Winston III, P.E.: 7 Things to Look for When Selecting a Building for Indoor Cultivation and Extraction

Indoor cannabis cultivation and extraction facility design are critical when determining the building you want to occupy. Mechanical, Electrical, Plumbing (MEP) & Structural Engineering play a considerable role in the success of your facility. Now that cannabis is becoming legal in more states, counties, and cities, cultivation and extraction facilities are scrutinized.

Not conducting proper due diligence can be very costly. There are some instances where I’ve seen clients miss important deadlines, which caused them to lose their licenses. Putting together a solid, experienced team before selecting a facility is vital. When budgeting, make sure you have a professional Architect and MEP Engineer(s) on board to help guide you along the road to finding an adequate facility. When searching for a facility, keep the following seven items in mind:

1. Zoning

Before doing ANYTHING, make sure you find a building that is appropriately zoned for cannabis cultivation. If you are building from the ground up, make sure your Architect understands the minimum property setbacks from schools, residential buildings, etc. Most cities or counties will have zoning maps available that show the “Green Zones.” The last thing you want to do is invest in a new venture to find out you can’t operate because you didn’t do your homework ahead of time.

Anthony Winston III, P.E. Owner/Electrical Engineer, Winston Engineering Inc

2. Parking

Recently my firm, Winston Engineering LLC, provided the MEP design for an extraction facility in Long Beach, CA. The client brought in their own Architect, who provided my firm with the floor plans. The plans were submitted to the city but were denied because there wasn’t enough parking! The building was built decades ago when parking regulations were much different than they are now. Due to this finding, additional parking had to be added to the property. This caused a significant issue because the client wanted to expand the building slightly.

This change affected the architectural plans, which also affected the MEP drawings. We were forced to redesign the facility, which cost the client more money and time.

3. Building Insulation

If you’re looking to purchase or lease an existing warehouse, make sure you understand your insulation requirements to maintain your grow temperature. For example, in California operators are required to adhere to Title 24, which governs energy efficiency. Unless you build insulated cannabis grow rooms within the warehouse, you will have to insulate your entire warehouse, which can be very costly.

4. Electrical

Once you narrow down a building, make sure the location has the electrical capabilities you need. Engage an Electrical Engineer with the loads you want to use so they can determine how many total amps you need. The other side of the equation is the voltage. Ideally, you want 480V, 3 phase as this gives you a lot more options for HVAC (Heating, ventilation, and air conditioning) and grow lights. If you can’t find 480V systems, 208V 3 phase would be the next best thing. PLEASE AVOID 240V, 3 PHASE DELTA SYSTEMS! Delta systems are usually found in very old buildings and have three different voltages (120V, 208V, and 240V). As shown in the diagram below, 3 phase 240V delta systems have a “wild leg” (sometimes called a “stinger leg”). On a typical 3 phase 208V wye system, if you placed a voltage probe on any leg and placed the other probe on neutral, the voltmeter would read 120V. On a 3 phase 240V delta system, if you read between the “wild leg” and neutral, the voltmeter would read 208V.

These systems can be a nightmare to design around and costly due to the additional electrical panels you may need. For example, if you have a lot of electrical components that use 120V (i.e., circulating fans, general receptacles, etc.), you will have to avoid the “wild leg,” leaving a large percentage of your circuit breaker slots empty (unless you have other 208V loads). With so many unused open slots, you may have to install additional subpanels. 

My firm has made the delta system work before, but it adds another layer of complexity.  

If you can only get a building with a 240V single phase, make sure you plan your grow room ahead of time. We recently had a client with a 240V single phase, 200A service, and we had to cycle rooms at different times.  We had another client with 240V single phase, 400A service but had to purchase expensive phase converters to turn single phase into 3 phase to power heavy-duty extraction machines. Again, these scenarios cost the client more time and money. 

If you’re building from scratch, be sure to engage the local utility to find out if there is enough available power you can tap into that will meet your needs. 

5. HVAC  

When leasing a building, make sure your landlord understands the potential facility modifications for indoor cultivation. As you probably know, indoor cultivation requires a lot of HVACS, so make sure your landlord knows about the impacts on their roof.  

We recently provided the MEP design for a large indoor cannabis facility where the client specified that the condensing units be placed on the roof. After the design had been completed, we later found that the client didn’t consult the unhappy landlord, and we had to redesign the MEP drawings. 

In another instance, the client insisted on rooftop units. We later found that the landlord had not provided a reinforced roof as previously agreed upon. Therefore, the roof could not withstand the additional weight.   

If you plan to put the condensing units on the ground, ensure you have enough space to place them. Quite often, there is not enough space due to clearance requirements or required parking.  

6. Sewage Capability  

If you’re going to lease a building, make sure you understand the sewage requirements. If you have a public sewage system, ensure that the main sewage line is large enough for your indoor cultivation facility. 

If you have a septic tank system, confirm the tank size and leech field are adequate for your needs.  A septic tank holds all the solids while the excess fluid flows to a leech field and drains in the soil. If the septic tank is not sized adequately, you have to account for the additional cost to replace it. If the leech field is not adequate, a percolation test (a test to determine the water absorption rate of soil) will need to be conducted. Typically, your city or county should have the results of the initial examination. There have been instances where the records were lost or thrown out due to the age of the building. Also, make sure the septic tank has been inspected. 

7. Demolition  

When selecting an existing building, consider the demolition cost. If you come across a building that was previously used for product manufacturing, you’ll find that demolition could potentially be very costly. Sometimes old equipment and abandoned electrical panels can be left behind, leaving you a mess to deal with.  

Very large, heavy equipment can be expensive to remove, especially components that are hung from the ceiling, such as FAUs (Forced air units). Removing large condensing units off the roof can also be very costly. Depending on the condition of the equipment, scrap metal companies may come to remove the equipment free of charge. 

Another item to consider is understanding the previous tenants intended use for the facility. One of my first projects was to repurpose a large warehouse. After the client had signed the lease, completed the architectural plans, and signed my firm to do the MEP design, we later found that the previous tenant used the facility for microchip manufacturing. Very toxic chemicals are used in the manufacturing of microchips. The health department was concerned that chemicals may have leaked into the soil. Luckily test results came back negative, but if they were positive, the client would’ve had to pay enormous fees to make the building safe again. 

We Can Help. 

If you own a cannabis business or are thinking about starting a cannabis business, we’d like to help. As a partnership of highly skilled and seasoned cannabis industry consultants and advisors, Bridge West Consulting is ready to guide you through this exciting and challenging landscape. Feel free to reach out to us anytime to schedule a consultation.