DIY marijuana grow room

Growing cannabis at home can be beneficial in many ways, not only by saving you money on poor quality weed, but it can also be very rewarding to create something that is your own. Before you start growing cannabis at home it is a good idea to plan your grow space. It is your grow space that will dictate the yield, what type of cannabis strain you grow, the type of lights you use and how many seeds you need to start with.

Planning your grow

When you are growing cannabis at home the minimum space required is 1 square meter, this will give you enough room for one large plant or a few smaller ones. Of course, you can grow on a windowsill or balcony if that is all the space you have available. But if you want your weed to last between harvests, I always recommend a minimum of a square meter.

You should also consider what growing equipment you will be using, for example, if you use CFL or LED lights you can get away with having the lights close to the plant without causing any burns. However, if you are using a HID light that gets very hot, then you need to make sure your lights are far enough away from the plant so as not to burn it.

What to consider when choosing your grow space?


Does the grow space have enough room (Height, width, and depth) to house the number of plants you want.


This is particularly important for stealth growers. When growing cannabis, the equipment can be noisy, having fans, ventilators, water pumps etc. running all night can be annoying for you or your neighbours. Make sure your fans or any noisy equipment are not attached to partition walls adjoining your neighbour’s property, or better still choose a room that is well insulated from your neighbours’ walls such as a basement. You should also take into consideration smell. Cannabis plants smell strong so make sure your extraction is not leading out near to your neighbour’s window.

Light proofing

I always against growing in your own bedroom. Light leakages are annoying, not to mention the heat that grow lights can give off. More importantly light leaks can damage your yields by causing your plants to flower earlier.

Air circulation

Cannabis plants need fresh circulating air to keep cool and prevent mold developing. Most growers use air ventilation systems to pump fresh air in and old air out of a grow tent. Make sure your grow has somewhere where the extracted air can be filtered out to.


This is key to having a successful grow. All cannabis grows unless they are done outside are energy intensive and require a wide range of electrical equipment. Make sure you have at a bare minimum a plug socket and an extension lead. Depending on the wattage of your lights you may also require a ballast.


To have a successful grow your plants need an environment that replicates nature as close as possible. For this you will need to create a climate that is warm and humid. This can be achieved with cannabis grow lights, ventilators, and humidifiers. However, be careful if you are growing in somewhere susceptible to cold such as a basement. Basements can be damp and cold both of which can lead to issues that will damage to your plants.

cannabis grow with thermometer


Obviously, you can carry water into your grow room but having access to a nearby water supply makes things a lot easier to water your cannabis plants. Save yourself the stress and grow somewhere that is reachable with a hose.

Grow tent vs grow room

When deciding on the best cannabis grow tent vs grow room set up for your cannabis plants it is important to understand the pros and cons of each.

Grow tents are a convenient option to growing cannabis because they are quick and easy to set up, relatively cheap and create a great environment for your plants. They are usually made of a black canvas material on the outside and on the inside, they are lined with either white or silver reflective plastic making them very energy efficient. You can purchase tents in a variety of sizes and shapes that will suit almost any grow big or small. 

A typical grow tent from amazon costs around $125 so it doesn’t have to break the bank, and at 48 x 48 inch (4 ft x 4 ft) it can easily fit a decent size grow of around 12-16 autos or 4 – 6 large photoperiods.

What size grow tent should i use for x number of plants?

There is no set answer on how large a grow tent needs to be because it is highly dependant on a number of variables.

  • What strain are you growing? If you are growing 4 high yielding photoperiods then you will need a bigger tent than if you are growing 4 autoflowers.
  • How do you plan on growing your plants? Using plant training methods such as LST, SCroG and mainlining will increase yields and make a plant wider. If you are using any of these methods to grow your plants then you may need a bigger tent.
  • How long do you plan on vegging your plants for? The vegetative stage of a plants life is where it puts on most of its size. With photoperiods the length of the vegetative stage is dictated by a change in the light cycle. If you are growing indoors you can choose when to change the light cycle from 18/6 to 12/12. The the longer you keep the plant in the vegetative stage the bigger the plant will grow.

What size grow tent for 1 plant?

If you are growing 2 average sized marijuana plants you will want at least a 2ft x 2ft grow tent. 

However thats not to say you can’t use a bigger tent. Some people use larger tents and veg for longer or train their marijuana plant to grow bigger and wider, if this sounds like you then you may want to opt for a 3ft x 3ft grow tent to give your plant more space.

What size grow tent for 2 plants?

The same principle applies, for two average sized marijuana plants you will need at least a 2ft x 4ft tent so that each plant has a 2ft x 2ft space to grow.

What size grow tent for 4 plants?

Lets say you are growing an averaged sized photoperiod strain you will want at least a 4ft x 4ft grow tent. This will give each plant roughly a 2ft x 2ft growing space with some room between them. Remember though if you are growing with much smaller plants such as autoflowers then you can probably fit 8 – 12 small autos in a similar space.

If you are growing high yielding strains and using training techniques to really boost bud production then you could increase the tent size to 6ft x 6ft allowing for 3 square feet for each plant which is plenty of room for those big yields.

Grow tent vs grow room setup

Grow tent

cannabis plant in grow tent

Positives to grow tents

  • Quick and easy to set up.
  • Great for novice growers.
  • Can be dismantled and stored away again after use.
  • Energy efficient, but not as efficient as a well-built grow room.
  • Grow tents are relatively airtight so can reduce the risk of pests & mold.

Negatives to grow tents

  • Space is more limited.
  • If you have a very small grow area such as a cupboard then it may be too fiddly.
  • More expensive than a self-built grow room.
  • Thin walls of the tent may need insulating in colder months.

Grow Rooms

Cannabis being grown in DIY grow room

DIY grow rooms are ideal for people that want to customise their grow area more and not be limited by the size of the tent. Building your own DIY grow room allows you to make better use of the space, especially if you have an odd-shaped room, such as a loft with a pitched roof and wooden beams that would otherwise be in the way. However, building your own grow room is not for everyone and where tents can be used, they are the easier option. If you have the know-how though constructing your own grow room can be rewarding and it can help you to make better use of the space allowing you to produce better yields.

Positives of DIY Grow Rooms

  • You can make better use of awkward spaces such as lofts or small cupboards.
  • If insulated well, they can be very energy efficient.
  • You are not limited by the shape and size of a tent.
  • You can custom build it to your own specifications.
  • It is cheaper to self-build.

Negatives to DIY Grow Rooms

  • They take more time and effort to construct.
  • They require a certain degree of know-how to construct one to a good standard.
  • If they are not insulated properly, they can be less energy efficient.
  • Less airtight which means there is more risk of pests.


If you are a complete beginner, I would recommend using a grow tent for your first grow. There is a lot that can go wrong when you are growing cannabis for the first time, grow tents minimise the risk of errors because they are much less maintenance and easier to set up. However, it also depends on where in your house you have decided to grow your plants. If you have chosen to grow in the attic, then a tent might not make the best use of the size and shape of the area.

If you are an experienced grower and you want to make best use of your available space, then making your own grow room can be incredibly fulfilling and can also help you to achieve great yields. 

Making a DIY grow room is more difficult than buying a tent, below are the most common issues with self-builds, so pay extra attention to these areas.

DIY grow room tips

  1. Make sure you insulate it well.
  2. Make sure you it is sealed from light leaks.
  3. Make it energy efficient by lining any walls with reflective materials such as black and white grow room panda film which is 90% reflective and 100% light proof.
  4. Make sure the floor is stable – if growing on carpet cover it with a waterproof material.

Joe Musgrave

An avid 420 enthusiast, grower, smoker and writer. Joe writes non stop, sharing his extensive knowledge in the field of cannabis with the wider online 420 community through blogs like ours at High Yield Strains.

Leave a Reply