Setting up a greenhouse in your backyard is a great way to keep your plants growing for longer, grow a wide variety of plants, and have a space for gardening all year round. But before you get started on this cool project, it’s important to think about a few things to make sure you’re making the right choices and getting the best results.

From deciding if you want to do the construction yourself or get some help, to figuring out the costs of different greenhouse options, planning carefully is super important. In this guide, we’ll talk about what you need to think about before building a greenhouse, give you a step-by-step plan for how to do it, and break down the costs involved in Australia.

What to Consider Before Building a Greenhouse in Your Backyard?

Building a greenhouse in your backyard can be a rewarding project, providing you with a controlled environment to grow plants year-round. However, before you start, there are several important factors to consider to ensure your greenhouse is a success. Here are some key points to keep in mind:

1. Purpose of the Greenhouse

First, determine why you want to build a greenhouse. Are you looking to extend the growing season, start seedlings, grow exotic plants, produce vegetables year-round, and keep all the lawn bugs away as much as possible? Understanding your primary goal will help you choose the right size, design, and features for your greenhouse.

2. Location

Choosing the right location is crucial. Your greenhouse needs ample sunlight, ideally receiving at least 6 hours of direct sunlight per day. The best spot is usually the south or southeast side of your property. Additionally, consider the proximity to water and electricity sources, as you’ll need these for irrigation and temperature control. Ensure the area is level and has good drainage to prevent water accumulation.

3. Size and Design

The size of your greenhouse should match your gardening goals and available space. A larger greenhouse offers more flexibility and growing space, but it also requires more resources to build and maintain. Common greenhouse designs include lean-to, freestanding, and attached models. Choose a design that complements your backyard and meets your needs.

4. Materials

Greenhouses can be made from various materials. The frame can be constructed from wood, aluminium, or galvanized steel, each with its pros and cons. Wood is aesthetically pleasing but requires more maintenance, while aluminium and steel are durable and low maintenance. The glazing, or covering, is typically made from glass, polycarbonate, or polyethene film. Glass provides excellent light transmission but can be heavy and expensive. Polycarbonate and polyethene are lighter and more affordable options.

5. Ventilation and Temperature Control

Proper ventilation is essential to prevent overheating and maintain healthy air circulation. Include roof vents, side vents, or exhaust fans in your design. Additionally, consider installing shade cloths or automated shading systems to protect plants from excessive heat. Heating systems, such as electric heaters or propane heaters, are necessary for colder months to maintain a stable growing environment.

6. Watering System

Consistent and adequate watering is vital for plant health. Consider installing an automatic irrigation system, such as drip irrigation or misting system, to ensure your plants receive the right amount of water. This will save you time and help maintain a consistent moisture level.

7. Budget

Building a greenhouse can be a significant investment, so it’s essential to set a realistic budget. Consider the costs of materials, tools, and any additional features like heating, ventilation, and irrigation systems. You might also want to factor in potential maintenance costs over time.

8. Permits and Regulations

Before starting construction, check local building codes and regulations. Some areas may require permits for structures like greenhouses. Ensure you comply with all local requirements to avoid any legal issues down the line.

9. Maintenance

A greenhouse requires regular maintenance to function effectively. This includes cleaning the glazing to ensure maximum light transmission, checking and repairing any damage to the structure, and maintaining the heating, ventilation, and irrigation systems. Be prepared to invest time and effort into keeping your greenhouse in good condition.

10. Future Expansion

Consider the possibility of future expansion. If you plan to grow a variety of plants or increase your gardening efforts, you might need more space. Designing your greenhouse with expansion in mind can save you time and money in the long run.

How to Build a Greenhouse: Step-By-Step

Building a greenhouse in your backyard can be a fun and rewarding project. Here’s a step-by-step guide to help you construct a basic greenhouse.

Step 1: Planning and Design

1. Determine the Purpose:

• Decide what you will grow and the size you need.
• Consider future expansion possibilities.

2. Choose a Location:

• Find a spot with at least 6 hours of direct sunlight daily.
• Ensure the ground is level and has good drainage.
• Check for proximity to water and electricity sources.

3. Select a Design:

• Choose between freestanding, lean-to, or attached designs.
• Decide on the shape and style that suits your space and needs.

4. Gather Materials:

• Frame materials: wood, aluminium, or galvanized steel.
• Glazing materials: glass, polycarbonate, or polyethene film.
• Additional materials: screws, nails, hinges, and door handles.

Step 2: Building the Foundation

1. Mark the Area:

• Use stakes and string to outline the greenhouse’s dimensions.

2. Prepare the Ground:

• Remove grass and level the ground.
• Add a layer of gravel for drainage if necessary.

3. Build the Foundation:

• For a wooden base, construct a frame using treated lumber.
• For a concrete base, pour a concrete slab or lay concrete blocks.

Step 3: Constructing the Frame

1. Assemble the Base Frame:

• Attach the frame to the foundation using brackets or anchors.

2. Build the Side Walls:

• Cut and assemble the frame pieces for the side walls.
• Attach the side walls to the base frame.

3. Construct the End Walls:

• Build the frame for the end walls, including door and window openings.
• Attach the end walls to the base frame.

4. Install the Roof Frame:

• Construct and attach the roof frame to the side and end walls.
• Ensure the roof has a slight slope for water drainage.

Step 4: Adding Glazing

1. Measure and Cut Glazing:

• Cut the glazing material to fit the frame sections.

2. Install Glazing:

• Attach glazing panels to the frame using glazing clips or screws.
• Seal gaps with weatherproofing tape or silicone sealant.

3. Install Doors and Windows:

• Attach doors and windows using hinges.
• Ensure they open and close smoothly.

Step 5: Ventilation and Temperature Control

1. Install Ventilation:

• Add roof vents or side vents for air circulation.
• Consider installing exhaust fans for better airflow.

2. Add Shade Cloths:

• Install shade cloths to protect plants from excessive sunlight.

3. Install Heating System:

• Add electric or propane heaters for cold weather.
• Ensure the heating system is safe and properly ventilated.

Step 6: Installing the Watering System

1. Choose a Watering System:

• Consider drip irrigation or misting systems for consistent watering.

2. Install Watering System:

• Set up the watering system according to the manufacturer’s instructions.
• Connect to a water source and test the system for leaks.

Step 7: Finishing Touches

1. Add Shelving and Benches:

• Install shelves or benches to maximize space for plants.

2. Organize Tools and Supplies:

• Set up a storage area for gardening tools and supplies.

3. Test the Greenhouse:

• Check the structure for stability.
• Ensure the heating, ventilation, and watering systems are working properly.

Should You Build the Greenhouse Yourself or Hire a Professional?

Deciding whether to build a greenhouse yourself or hire a professional depends on several factors, including your skills, time, budget, and the complexity of the project. Here’s a guide to help you make an informed decision.

Building the Greenhouse Yourself

Pros:

1. Cost Savings: Building a greenhouse yourself can be more cost-effective, as you save on labour costs.
2. Personal Satisfaction: Completing the project on your own can be very rewarding and give you a sense of accomplishment.
3. Customization: You have complete control over the design and can make changes as you go along.
4. Learning Experience: Building the greenhouse can be an educational experience, enhancing your skills in construction and gardening.

Cons:

1. Time-Consuming: Building a greenhouse requires a significant time investment, especially if you have little experience.
2. Skill Requirements: You need basic carpentry and DIY skills. If you lack these, the project can become challenging and frustrating.
3. Tools and Equipment: You’ll need to have or rent specific tools, which can add to the overall cost.
4. Potential for Mistakes: Without professional expertise, there’s a higher chance of making mistakes that could affect the greenhouse’s functionality and durability.

Hiring a Professional

Pros:

1. Expertise and Experience: Professionals have the skills and experience to build a greenhouse efficiently and correctly.
2. Time Efficiency: Hiring a professional can save you a lot of time. They can complete the project faster than you likely could on your own.
3. Quality Assurance: Professionals are more likely to deliver a high-quality, durable structure that meets your specifications.
4. Less Stress: You can avoid the stress and hassle of a DIY project, leaving it to experts who handle all aspects of the construction.

Cons:

1. Higher Costs: Hiring a professional can be more expensive due to labour costs.
2. Less Personal Involvement: You might have less control over the project, although a good contractor will work closely with you to meet your needs.
3. Finding the Right Professional: It can take time to find a reputable contractor. You’ll need to do some research and possibly interview several candidates.

Considerations for Making Your Decision

1. Budget: Determine how much you’re willing to spend. If budget is a significant concern, doing it yourself may be the better option.

2. Time: Assess how much time you can dedicate to the project. If your schedule is tight, hiring a professional could be more practical.

3. Skills: Be honest about your DIY skills. If you’re comfortable with construction projects, you might enjoy building the greenhouse. If not, a professional can ensure it’s done correctly.

4. Project Complexity: Consider the complexity of the greenhouse you want. Simple designs are more manageable for DIY, while more complex structures might require professional help.

5. Future Maintenance: Think about long-term maintenance. If you build it yourself, you’ll be more familiar with the structure and any potential issues.

Cost of Building a Greenhouse in Australia

The cost of building a greenhouse in Australia varies widely based on several factors, including size, materials, design, and whether you opt for a DIY approach or hire professionals. Here’s a breakdown of the typical costs you might encounter:

1. Size and Type

• Small Greenhouses (Up to 10m²):
  • DIY Kits: $500 to $2,000
  • Professionally Built: $2,000 to $4,000
• Medium Greenhouses (10m² to 30m²):
  • DIY Kits: $2,000 to $6,000
  • Professionally Built: $4,000 to $10,000
• Large Greenhouses (30m² and Above):
  • DIY Kits: $6,000 to $15,000+
  • Professionally Built: $10,000 to $30,000+

2. Materials

• Frame Materials:
  • Wood: $50 to $100 per linear meter
  • Aluminium: $70 to $150 per linear meter
  • Galvanized Steel: $100 to $200 per linear meter
• Glazing Materials:
  • Polyethylene Film: $5 to $10 per square meter
  • Polycarbonate Panels: $20 to $50 per square meter
  • Glass: $40 to $100 per square meter
• Foundation and Base:
  • Gravel Base: $20 to $40 per square meter
  • Concrete Slab: $60 to $100 per square meter

3. Additional Costs

• Ventilation and Heating:
  • Manual Vents: $100 to $300 each
  • Automated Vents: $300 to $700 each
  • Heaters: $200 to $1,000 depending on type and size
• Irrigation Systems:
  • Drip Irrigation Kits: $100 to $500
  • Misting Systems: $200 to $1,000
• Doors and Windows:
  • Basic Doors: $100 to $300
  • Custom Doors or Windows: $300 to $1,000+

4. Labor Costs

• DIY Approach: Minimal additional cost if you do the work yourself, but factor in the cost of tools and equipment if you don’t already own them.
• Professional Installation: $50 to $100 per hour, with total costs depending on the complexity and size of the project. Full installation for a medium-sized greenhouse can range from $2,000 to $5,000.

5. Permits and Regulations

• Building Permits: Varies by location and greenhouse size, typically $100 to $500. Check with your local council for specific requirements.

Overall Cost Estimates

• Small DIY Greenhouse: $500 to $2,000
• Medium DIY Greenhouse: $2,000 to $6,000
• Large DIY Greenhouse: $6,000 to $15,000+
• Small Professionally Built Greenhouse: $2,000 to $4,000
• Medium Professionally Built Greenhouse: $4,000 to $10,000
• Large Professionally Built Greenhouse: $10,000 to $30,000+