Cannabis Grow Room Design Considerations

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Cannabis Grow Room

The overall perception of cannabis is changing dramatically in the United States as lawmakers and citizens alike begin to realize the benefits the plant can provide for the medical sector.

31 states have legalized marijuana for medical purposes, and nine states and the District of Columbia have laws on the books making the plant legal for recreational purposes. In addition, there are bills moving through Congress that aim to recognize state legalization efforts, which could potentially legalize marijuana and hemp at the federal level as well.

As the market for legal cannabis continues to grow, the need for growers and distributors will continue growing alongside it. Savvy growers must be able to scale up their operations quickly and efficiently to meet increasing demands as the success of legalization efforts progresses.

How to Construct Your Indoor Grow Room

Like all plants, cannabis requires specific levels of nutrients, lighting, humidity, and air circulation to create an optimal growth environment. While these specifications may sound complicated, thanks to advancements in construction and other technologies, building a grow room is now far simpler than it has been in the past.

As cannabis goes mainstream, products and services have been pushed to market specifically for growing marijuana and hemp plants. Some of these innovations include:

Modular Grow Rooms

The pre-fabricated building industry provides everything from office spaces to locker rooms to classrooms. As such, it’s no surprise that some modular building companies are taking advantage of explosive growth in the cannabis sector. For growers who have the space for small additional structures, erecting a fully equipped pre-fab grow room can be a good option for getting started, or for a quick and easy expansion of an existing grow operation.


Crop markets fluctuate, but the cannabis market is likely to grow for some time. For farmers or hobbyists with existing greenhouses, these facilities can be converted into suitable growth environments for cannabis plants. With proper lighting, air circulation, temperature control, and other factors, a greenhouse can make a perfect hydroponic grow room for cannabis plants.

Existing Rooms

For entrepreneurs seeking to break into the cannabis market, converting existing space into a grow room might be the most straightforward option. Basements are often ideal because they maintain a similar temperature and moisture environment year-round, making them easier to control in terms of environmental factors. However, any number of spaces can be converted for successful use as grow rooms, including spare bedrooms, garages, sheds, walk-in closets, and more.

Not everyone has room for additional structures on their property, but a range of services have popped up to help growers and potential growers convert unused spaces into effective cannabis grow rooms. For the uninitiated, seeking expert advice about high-intensity lights, HVAC systems, plumbing, and building codes can avoid a lot future headaches. Aside from general cannabis consultants, individual lighting, HVAC, plumbing, electricity, and other vendors can also offer you quality advice about each portion of your legal indoor grow room set up.

Creating a Controlled Growth Environment

Successfully controlling environmental factors is key to creating a successful indoor grow house. You’ll need to focus on the following factors to give your plants the best chance at growth:

Grow Room Dehumidifiers

Any growing plant experiences transpiration, which constantly transmits moisture into the air. Your HVAC system is crucial to controlling humidity and ensuring your plants don’t develop harmful mold or mildew that can kill them or make them unsalable.

When purchasing a grow room dehumidifier, consider the following: the amount of water plants get daily, the dehumidification rating of your temperature control system, and whether or not you’re using CO2. Most plants transpire nearly all of the water they are given, so determining how much water you put in each day will help you determine how much you need your grown room dehumidifier to remove from the air each day.

Temperature Control

Constant temperature control is crucial for cannabis growth. Plants will grow slowly if temperatures are too cool, but they can also suffer damage if temperatures are too high. Many indoor growers use air conditioners to control room temperatures and fans to provide air circulation that will keep lights from scorching plants. Depending on your geographic location, you may also need to insulate the room to maintain constant optimal temperatures.

Fresh Air

Marijuana and hemp plants require fresh air to grow properly, so your HVAC system must be capable of constant air circulation. If the quality of your outdoor air is a concern, filters can be applied to ensure that the quality of air indoors remains high. If the smell of your grow room is an issue, carbon filters and ozone filters can also be applied to your exhaust system to help reduce the distinct odor emitted by healthy cannabis plants.


Proper lighting for your grow room will likely be the largest long-term cost for your operation. High wattage HID and HPS bulbs are typical in many grow operations, and these lights draw a significant amount of power that will have a noticeable impact on your utility bill.

You’ll also need to make sure that your electrical system can handle the increased load, and you may need to update components to avoid power failures and ensure safe operation. Recent advancements in LED lights have made them more popular for use in grow operations because they use less power and last longer than traditional bulbs.


As a general rule of thumb, you’ll need a gallon of water per day for each pound of cannabis you are growing. As such, you’ll need an irrigation system for larger grow rooms, or a spigot and hose that can reach your plants in a smaller operation. You’ll also need to install a floor drain and waterproof the walls and floor with tile or moisture-resistant drywall to ensure that you don’t develop rot or mold.

Don’t Be Afraid to Ask for Advice

As cannabis legalization advances and drives market growth, there is little doubt that best practices for legal growth operations will continue to develop. In the meantime, be sure to rely on your HVAC, plumbing, electric, and lighting vendors for the advice you need to make sure that your indoor grow room is safe and efficient.




Image Credit: Canna Obscura/

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