How To Align Greenhouse (Garden Advice)

Starting from scratch is a daunting task, but we are here to help you. To make it easier, we’ve broken down the process into steps that will walk you through the construction of your new greenhouse.

HOW TO Align your Beds and Greenhouses – YouTube
– Proper alignment is essential for a greenhouse’s stability and functionality.
– Anchoring a greenhouse to the ground helps ensure its stability during various weather conditions.
– Small greenhouses require specific techniques for alignment and security.
– Different types of greenhouses, such as plastic and polycarbonate, have unique considerations for alignment.
– Exploring additional resources on greenhouse positioning and placement can provide valuable insights.

1. Locate the Greenhouse

Greenhouse locations should be level and free of obstructions, such as trees and buildings. A greenhouse should be located in a sunny area; however, it is also important to consider the wind direction when choosing where to place your greenhouse. 

Wind can cause damage if it hits your structure, so try to avoid low-lying areas that will make it difficult for you to move around in with ease or get into your greenhouse once it’s built.

When it comes to aligning your greenhouse, anchoring it securely to the ground is crucial. Our easy-fix guide on how to anchor a greenhouse to the ground provides step-by-step instructions to ensure the stability and proper alignment of your greenhouse.

2. Assess Current Placement

Before you start building your greenhouse, it’s important to assess the current placement. You want to make sure there are no obstacles in the way and that your greenhouse won’t be obstructed by unwanted plants, animals, people or insects.

You also want to check for wind direction, as well as trees and other structures that can block sunlight from reaching your greenhouse.

3. Look for Obstacles

Check for power lines, trees and other obstacles.

Look for water pipes and underground services. You can do this by calling your local utility company (the phone number will be on your bill). They’ll come out and check if they need to move any lines or pipes that you might be planning on digging around.

Check neighbours too – ask them to let you know if they plan on building something close to the greenhouse so there are no surprises later!

If you have a small greenhouse, proper alignment is essential for optimal growth. Learn how to align and secure your small greenhouse with our easy-fix tips in the article on how to anchor a small greenhouse.

4. Check the Sun’s Angle

To determine the angle of the sun, look for a shadow cast by an object, like a tree or building. The tip of this shadow gives you your angle. However, in order to accurately measure your greenhouse, you’ll need to use math.

Let’s say that you’re looking at a 45° shadow and want to find out how long it is (in feet). First, convert degrees into minutes: 45° = 1/8th of 90° x 60 seconds / minute = 5/8th of 10 minutes x 5 seconds per minute / second = 5/8th of 50 seconds per hour x 60 minutes per hour = 380 inches (5′ 7″) long!

5. Calculate the Necessary Distance

Calculate the necessary distance: The minimum distance between your greenhouse and the sun is calculated as follows:

Distance = (Angle of Sun + 50) x Length of Path to Greenhouse x Height of Greenhouse.

Where Angle of Sun = angle from North to South at which you want your crops to grow towards; Length of Path = shortest distance from greenhouse to sun; Height = height of crops you want in your greenhouse

6. Plan Your Path

Before you start building, it’s important to plan your path. You will want to make sure you have enough space to move around, as well as store any materials needed for the greenhouse construction.

1Assess the area and determine the desired path
2Consider the layout and function of the space
3Identify potential obstacles or hazards
4Select appropriate materials for the path
5Install the path, ensuring proper alignment and stability

7. Clear Your Pathway

The last step in the process is to make sure your pathway is clear of any obstacles. You want to be able to easily walk into and out of your greenhouse, so it’s important that you don’t trip over anything while you’re going about your business.

To protect your greenhouse from strong winds and maintain its alignment, anchoring it down is a must. Discover effective techniques in our easy-fix guide on how to anchor a greenhouse down and ensure the stability of your structure.

8. Dig Holes for Footings

To determine the hole size, take measurements of your greenhouse and convert them into the following measurements:

  • Length (cm), Width (cm), Depth of Soil (cm)
  • Distance Between Posts (cm)
  • Distance between Posts and Edge/End Wall (cm)

You’ll need to know these dimensions for each location where you’re going to install footings.

9. Add Concrete to Footings

Now you’re ready to add concrete to your footings. You can use a wheelbarrow, shovel, cement mixer or bucket and hoe. 

A wheelbarrow is great for mixing and moving materials around the greenhouse site. To mix the concrete, pour water into one end of your wheelbarrow and then slowly add cement powder until it becomes thick enough to work with (don’t worry if there are still clumps!). 

It’s best if you have similar-sized bags so they will blend well together without leaving lumps in your mix. Add just enough water so that the mixture begins to come together but doesn’t look or feel soupy or overly dry at all times throughout this process!

10. Place Posts & Remove Facing Spikes

Now that you have the base and sides erected, it’s time to place the posts in their proper positions and secure them. 

The first thing you’ll want to do is remove those facing spikes from all your 4×4’s using a crowbar or sledgehammer. You can also use a post-hole digger if you don’t have a crowbar handy!

Next, place the posts on top of their respective holes: one at each corner and two more spaced evenly between them (see diagram). 

These will serve as anchors for your greenhouse framing and provide structural support for attaching your plastic covering later on. 

Make sure they’re square which means they should be perfectly vertical and level before driving them into the ground with another sledgehammer or driving block if necessary.

Aligning a plastic greenhouse requires specific considerations for stability. Our easy-fix guide on how to anchor a plastic greenhouse offers valuable tips and techniques to secure your plastic greenhouse and keep it properly aligned.

11. Put in Uprights & Purlins

Now that your panels are at a perfect 90 degrees to each other, you can begin installing the uprights. 

Use a spirit level to check for plumb as you place them, and then use a tape measure to check for square; remember that the ends of the uprights should be flush with the end of your base panel (as shown in Image 6). 

Finally, make sure everything is level by using another spirit level on top of one of your uprights (Image 7).

1Position and install uprights
2Attach purlins to the uprights

12. Attach Ridge Beam to Ends of Purlins

Again, using galvanised nails, attach the ridge beam to the ends of your purlins. You will probably have to use some shims here and there in order for it to sit evenly on top of your purlins.

13. Install Front/Back Wall Studs & Attach End Walls or Dormer Frames to Them

To attach the end walls or dormer frames to the front and back wall studs, you will need to:

Make sure all four walls are level and plumb. Use a level to check each wall, and use a plumb bob to double-check it. (You can also use a tape measure.)

Attach one side of your first end wall by screwing through both layers of plywood into the studs in your greenhouse frame.

Install screws for any braces or bracing between this wall and others if so specified by manufacturer’s instructions. If no specifications exist for this type of structure, simply install each brace as if it were an additional stud going across from side to side in your greenhouse frame.

1Install front wall studs
2Attach end walls or dormer frames to front wall studs
3Install back wall studs
4Attach end walls or dormer frames to back wall studs

14. Insert Window Frames into End Walls

Window frames are inserted into the end walls of your greenhouse so that they can be propped open during warm weather or closed to keep out insects when it’s cold. 

These windows are usually installed before the roof is put on, but if you don’t have a drill press yet, it’s fine to do this step after everything else is assembled.

To insert a window frame in an end wall: With the frame against one of your two-by-fours that serve as braces for each end wall (Photo 4), use an 18-gauge drill bit on a corded drill with variable speed control to bore holes through both ends of the brace boards where they overlap (Photo 5). 

Then insert 1/8″ carriage bolts through these holes and into each side of each window frame; tighten them with washers and nuts (Photos 6 & 7). Set aside all six bolt assemblies for now—you may need them again later!

For those who have a polycarbonate greenhouse, aligning it correctly is essential for optimal performance. Our easy-fix guide on how to anchor a polycarbonate greenhouse provides valuable insights and techniques to ensure the proper alignment of your polycarbonate greenhouse.

15. Replace Temporary Roof Panel Screws with Galvanised Nails before Removing Scaffold Beams

Replace Temporary Roof Panel Screws with Galvanised Nails before Removing Scaffold Beams

The temporary roof panel screws should be removed before removing the scaffold beams and replaced with galvanized nails instead, as they will hold the panels in place until the final roof is installed.


Congratulations, you’ve completed the first step of your greenhouse construction project! You’re now ready to begin building the actual structure and filling it with plants. 

If you have any questions about this process or want more information on how to build a greenhouse, feel free to contact us.

Further Reading

Here are some additional resources to further explore the topic of greenhouse positioning and placement:

Thompson & Morgan: Where to Position Your Greenhouse

This comprehensive guide from Thompson & Morgan provides insights on the ideal placement of a greenhouse, considering factors such as sunlight exposure, wind direction, and accessibility.

Bootstrap Farmer: Ideal Location for a Greenhouse

Learn about the ideal location for a greenhouse and key considerations in this informative article by Bootstrap Farmer. Discover tips on maximizing sunlight, protecting from harsh elements, and more.

Gardening Know How: Where to Put Greenhouse

This article on Gardening Know How offers valuable insights on choosing the right location for your greenhouse, including information on sunlight, drainage, and nearby structures.


Here are some frequently asked questions about greenhouse positioning and placement:

Q: What is the best direction to face a greenhouse?

A: The best direction to face a greenhouse is typically south or southeast. This orientation allows the greenhouse to capture the maximum amount of sunlight throughout the day.

Q: How far should a greenhouse be from a house or other structures?

A: It is recommended to keep a greenhouse at least 6 to 10 feet away from nearby structures. This distance allows for proper air circulation and prevents potential damage from shading or water runoff.

Q: Should a greenhouse be placed on a slope?

A: Ideally, a greenhouse should be placed on a level surface to ensure stability and ease of access. However, if a slope is unavoidable, proper leveling and drainage measures should be taken to prevent water pooling and structural issues.

Q: Can a greenhouse be positioned under trees?

A: It is generally not recommended to position a greenhouse under trees. Trees can create shading, block sunlight, and drop leaves or branches that may damage the greenhouse structure or obstruct its functionality.

Q: Should a greenhouse be positioned close to a water source?

A: Having a water source in close proximity to a greenhouse is advantageous for irrigation purposes. Placing a greenhouse near a water source allows for convenient access and efficient watering of plants inside the structure.