I can’t imagine what it was like when there was no rooftop garden in my house. 

My energy bill every month was on the high side as a result of heat especially during summer. The story changed when my old time friend Peter visited me. He told me about the importance of rooftop gardens in the house. 

My desire to reduce the cost of energy bills and my love for wildlife inspired me to conduct a research to know how much it’ll cost to build a rooftop garden.

Here is what I found out:

The cost of an extensive rooftop garden with growing medium of 2 – 4 inches depth ranges from $100 – $500, while the cost of an intensive rooftop garden with growing medium of 5 – 10 inches depth ranges from  $70 – $200 per square foot. However, the types of plants and facilities can affect the overall cost.

The cost of building a rooftop garden varies from one location to another. No matter where you live, you can still build a rooftop garden within the above cost.

To make a better decision, here is a complete cost breakdown.

It Costs $100 – $3,000 (On Average) To Use Existing Rooftop

The cost of turning a section of your existing rooftop into a garden is different from using the complete rooftop.

Irrespective of the rooftop garden you want to create, this cost should cover it. Some rooftops are not initially designed for a garden but you can turn such a rooftop into a garden. 

Get professional engineers to help you turn the rooftop into a beautiful garden.

The average cost of using a section of concrete, hardwood, metal rooftop for Garden is $30 per square foot, while the average cost of converting the complete rooftop to a garden is $200 per square foot.

If your rooftop is more than 1 sq ft and you want to use the complete rooftop, then the cost will be higher.

For example, the cost of 4 square footages will be 4 x $200 = $800. This is required to get the complete rooftop ready for use. The cost includes both soil and materials you may likely use to grow productive plants.

Using a section of rooftop for growing plants is less-expensive. Because you might only use 1 or 2 planter pots and fewer plants.

It’s cheaper to construct planter pots than buying. Especially when using a section of your rooftop for a garden.

The cost covers the materials you would require to construct a productive planter pot. 

Let’s breakdown the various costs of materials required when using a section of your rooftop for growing plants.

The Cost Of Planter Pots Ranges From $30 – $200

Planter pots come in different sizes, shapes, and designs. The cost to build or buy planter pots varies from one location to another. There are many factors that impact the cost of planter pots — such as shipping costs and type of pots.

The cost of building a planter pot is relatively cheap compared to when buying. Already-made planter pots come with different compartments and for growing different types of plants (e.g., Tomatoes, Cucumbers, Potatoes). 

If you’re going to use your rooftop for a garden and relaxation center, then you should use already-made planter pots. 

The already-made planter pots serve two purposes: 

• For decoration and beautification
• For growing plants

These planter pots are expensive because of their functions and the materials that go into the production.

It’s Cheaper To Build a Planter Pot Than to Buy Already-made Planter

On average, the cost of building a planter pot ranges from $20 – $120. The primary  expense that goes into it is the cost of materials.

Interestingly, you can get some of the materials for free. However, you may not use the planter pots you built for decoration or beautification if you’re not skilled in production. 

Although some people use DIYs Planter pots for decoration as well. Keep in mind that the cost will go higher when building planter pots with different compartments. 

An Average Cost Of Raised Bed Is $20 – $1,000

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The cost of a raised bed is not constant. The materials you’ll use for the construction is the determinant factor.

The cost varies from one location to another. Irrespective of where you live, the average cost of $20 – $1,000 should get you a raised bed planter.

Let’s look at what it will cost to build different types of raised beds.

The Average Cost of Wooden Raised Beds is $10 – $1,000

Metal raised bed is more expensive than a wooden raised bed. The average cost for a supported wooden raised bed is $10 – $1,000 outside the cost of soil. The cost depends on the size and type of material you want to use.

The Average Cost of a Metal Raised Bed Ranges From $200 – $2,000

The types of materials that are used to construct a raised bed and the sizes are what  determines the final cost. 

It’s important you know the cost will be higher when building a raised bed with compartments. However, The cost of soil is not inclusive.

You can either minimize the cost by choosing to construct 2 – 3 compartments.

This is the average cost for you to use raised beds of different sizes in your rooftop garden.

Ensure your budget is within the average cost above.

The Cost Of An Irrigation Ranges From $50 – $2,500

An irrigation system is very important, if you want to improve the plant’s growth rate. Irrigation also helps to increase long-term vegetation success.

With irrigation you can always cultivate plants in and out of season. Irrigation system helps to reduce or stop the stress of carrying water to the rooftop. 

The Rooftop garden needs a drip irrigation system if you want to have productive plants. The function of irrigation can’t be over emphasis — especially when your garden is on the top roof.

Plants need constant water supply and this can’t possibly be achieved without functionable irrigation system connected to the rooftop.

The average cost to install irrigation for a small section of rooftop garden ranges from $50 – $500, while the average cost per acre ranges from $1,500 – $2,500.

The size of rooftop, materials, and nature of the project are factors that determine the cost.

You can get a drip irrigation system as low as $50 if your rooftop is close to the water system and the project is not difficult to carry out.

The cost of a water supply system for an intensive Rooftop garden is higher than the cost of a water system for an exclusive rooftop garden.

It is higher because the drip irrigation system has a larger area to cover compared to an exclusive water system.

Is Rooftop Garden Staircase Expensive?

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Staircase is very important for a rooftop garden. It makes it easy for you to access the top of your roof.

Without a sturdy and stable staircase, it will be difficult to access your rooftop garden. That’s why you need a staircase into your rooftop garden.

There are 3 different types of staircase you can construct to your rooftop:

• Metal staircase
• Concrete staircase
• Hardwood staircase

The cost of constructing each of the stairs is different. Because different materials are used to produce each of them. 

How Much Does Rooftop Metal Staircase Cost?

The cost of constructing the metal staircase that leads to the rooftop varies. Variations in the cost is based on the materials and the locations.

The average cost to construct rooftop metal staircase ranges from $50 to $100. The cost includes both materials and labor.

Metal staircases don’t have the full capacity to withstand weather conditions. However, a painted metal staircase can withstand any weather conditions.

Metal staircases have some limitations when compared with hardwood and concrete staircases.

The cost of building a straight or spiral metal staircase is different. Designs is another factor that either increases or decreases the cost.

Metal steps require maintenance from time to time. If the metal stairs are directly exposed to weather conditions may require repaint every year to avoid rust. 

On the average, a metal staircase will cost $10 – $50 to maintain functionable metal staircase. The size of the staircase is what determines the cost for the maintenance.

Cost Of Build Concrete Staircase To Rooftop?

What determines the cost for building concrete staircase that lead to rooftop are:

• The number of steps
• The wideness
• The length

The average cost of constructing concrete steps ranges from $200 – $800. 

For example, a staircase that is 2 feet wide, 10 inches deep will likely cost $50 to construct one step. The cost is inclusive of materials and labor.

Concrete staircase has the capacity to withstand any weather conditions and is also durable.

Concrete steps are durable and sturdy when they are constructed to a rooftop and exposed to weather conditions. They can also serve as a garden. 

The materials that go into the construction and the labor are what determines the final cost. The cost of building concrete stairs varies from one location to another. 

You need to enquire what it will cost to build concrete stairs in your area. Measure the length from the ground floor to the roof. The measurement will enable you to know the number of steps that it will contain.

Concrete stairs require less or none maintenance unlike other stairs. Concrete stairs only have one-off cost, which is the cost of construction and installation.

Is Hardwood Steps To Rooftop Garden Expensive?

Hardwood staircase that leads to a rooftop is not expensive when you consider the cost of building concrete or metal stairs.

The average cost of building hardwood stairs that lead to a rooftop ranges from $50 to $100 per staircase — excluding materials. 

The cost of constructing hardwood including materials and labor ranges from $100 to $300. This price includes the installation, labor, and materials.

Hardwood steps are designed to withstand the fierce weather conditions outside. It has low maintenance cost and it is usually yearly most times.

The steps can easily be moved to different locations if there is a need for such. Hardwood step is cost effective considering other stairs. 

Irrespective of the materials used to build the hardwood staircase, it is highly durable and easy to maintain. Once the woods are painted, they have the capacity to withstand weather conditions.

Now that you know the cost for constructing a garden on your old rooftop, then let’s take a look at the cost breakdown for constructing a new rooftop garden.

Cost Of Constructing New Rooftop Garden

There are different types of rooftop you can convert to a garden. The materials that go into the construction of these roofs are what determines the cost.

For example, the materials used in constructing concrete roofs are different from hardwood and metal roofs.

Because of the materials, a concrete rooftop garden is costlier than a hardwood rooftop garden. Likewise, a concrete rooftop garden is more durable and able to withstand weather conditions than a hardwood rooftop garden.

Rooftop gardens that have the capacity to withstand the weather conditions are more expensive than ones without capacity to stand weather elements.

Basically, there are 3 types of rooftop garden:

• Concrete rooftop garden
• Hardwood rooftop garden
• Metal rooftop garden

The cost of building or constructing each of these rooftop gardens varies. Then how much does each rooftop cost? 

Let’s look at the individual cost.

Concrete Rooftop Garden Cost How Much?

Concrete is quite expensive because of the materials. You need cement, gravel, sand, wood, and other materials before you can build a concrete rooftop.

You need the service of a qualified builder to construct a concrete rooftop otherwise, you will waste your money when trying to do it by yourself.

Average cost of building a concrete rooftop garden ranges from $500 – $1,000, while the cost of constructing concrete rooftop gardens for commercial use ranges from $2,300- $5,000. 

Extensive rooftop gardens cost about $10 – $50 per square foot, while intensive rooftop gardens cost from $20 – $200+ per square foot.

Concrete rooftop gardens are expensive because of the production materials and the labor. 

Here are some of the materials:

• Wood. 
• Slate
• Sand
• Water
• Cement 
• Nails 
• Iron
• Metals
• Asphalt
• Clay

The combinations of these materials above make concrete rooftop expensive. 

Concrete roofs have the capacity to withstand weather conditions and are highly durable. 

Concrete rooftop gardens can be used to cultivate plants without planters. You can prepare the floor to grow your plants or planter pots. 

Cost Of Building Hardwood Rooftop Garden

There are factors you have to consider when you choose to use a hardwood roof for a garden. Mainly when you want to use the floors. 

Let me quickly tell you what it will cost to build a hardwood rooftop garden.

The average cost of constructing a rooftop garden with cedar shake wood ranges from $200 to $1,000. 

Cedar wood has the capacity to last between 30 to 40 years. Cedar wood doesn’t easily get damaged. 

The woods are built to withstand the weather conditions outside. When using a hardwood roof for a garden, you need to create another layer. The layer will be in between the hardwood and the plants.

Such a layer will protect the wood from getting damaged by the water and soil. It will serve as waterproof and insulator to the hardwood.

However, you don’t need a layer when using planter pots or supporting raised beds to grow your plants. Planters pots or raised beds will prevent the wood from getting damaged by water and soil. 

You need to properly channel all water out from the hardwood rooftop when using it for garden. Protect the wood against insects and pests that may likely destroy the wood.

Not all chemical substances are friendly to hardwood. Therefore watch the types of chemical you spray on your hardwood.

Hardwood roof doesn’t absorb heat. Using it for rooftop gardens will make the plants yield productivity. 

Drip water irrigation that is connected into the hardwood rooftop garden has to be properly connected to avoid any leakage that will damage the roof.

Metal Rooftop Garden: How Much Does It Cost To Build?

Most people don’t really use metal rooftop gardens because they conduct heat. The metal roof delivers a high amount of heat from the exterior.

The drawback with a metal rooftop is the heat that it emits externally. The heat has the capacity to destroy or retard the plant’s growth.

The average cost of constructing a metal rooftop garden ranges from $500 – $2,000. This cost includes installation, planter and any other materials you wish to use on your garden.

Metal rooftop gardens are hard before you see people use it for gardens because of the heat. 

These are the cost of producing different types of rooftop gardens that will yield productivity. 

Conclusion 

Here you have a comprehensive cost breakdown of building a rooftop garden. Also, you know how much it will cost you to convert your old roof into a garden.

Then, the choice is yours to decide if you will construct a rooftop garden in your home to enjoy all the benefits it has. Rooftop gardens bring you closer to green life and make your house interior cool.