The cost of a green roof varies widely from project to project depending on unique factors such as the size of the rooftop, the type of plants used, and your location. However, the national average cost of a green roof is between $15 and $50 per square foot.
Green roofs are becoming increasingly popular as a way to combat the effects of climate change. They also help reduce air pollution and insulate your home to save on energy bills. So, if you’re looking to install a green roof, be ready to pay a hefty sum upfront, but keep in mind that the benefits may well be worth it!
Average Green Roof Costs
| National Average Cost | $24,000 |
| Typical Price Range | $13,000 – $50,000 |
| Extreme Low End Cost | $5,500 |
| Extreme High End Cost | $80,000 |
Green roofs are found in both commercial and residential buildings. For a typical home, a green roof would cost between $13,000 and $50,000.
Green roofs, aka living roofs, are becoming more popular because they can save you money on your energy bills. The cost of converting your roof to a green roof depends on a number of factors, including the size of the roof, the type of vegetation, and the climate.
In general, green roofs can cost anywhere from $15 to $50 per square foot.
Green Roof Cost Estimator by Home Size
The cost of a green roof depends on the specific materials used and the geographical location of your home. A typical green roof installation costs between $13,000 and $50,000 per 1,000 square feet of roof, including labor and materials.
To get an estimate of how much your green roof will cost, you have to know the size of your roof in square feet. If you don’t already know it, you can use this formula for a size estimate:
- Home square footage x 1.5 = Roof square footage
We calculated total project cost estimates for several home sizes in the table below, based on the low and high rates of $15 to $50 per square foot.
| Home Size (sq ft) | Approximate Roof Size (sq ft) | Total Cost Estimate |
| 1,000 | 1,500 | $22,500 – $75,000 |
| 1,500 | 2,250 | $33,750 – $112,500 |
| 2,000 | 3,000 | $45,000 – $150,000 |
Note: These cost estimates are based on a per-square-foot cost that could be lower for larger projects. You likely won’t spend more than $80,000 on a new green roof, unless your project is especially large or difficult to install.
Green Roof Cost by Type
There are different types of green roofs you can install. Some are more complex, so they tend to cost more, while others are simpler and easier to install, so they cost less. Let’s look at the relative costs of different types of green roofs.
| Green Roof Type | Cost per 1,000 Square Feet*labor and materials included |
| Intensive Green Roof | $21,700 – $38,300 |
| Semi-intensive Green Roof | $15,000 – $30,000 |
| Extensive Green Roof | $10,000 – $20,000 |
| Blue-Green Roof | $13,000 – $32,500 |
| Biosolar Green Roof | $25,000 – $35,000 |
Intensive Green Roof
Intensive green roofs come with a higher price tag than other types of green roofs, ranging from $21,700 to $38,300 per 1,000 square feet. They typically have a soil layer at least 8 inches deep and are designed for large, high-profile buildings.
An intensive green roof can support a greater variety of plant life than simpler, shallower green roofs. They’re typically found in urban areas, where there is a need for more greenery.
Semi-intensive Green Roof
A semi-intensive green roof typically costs around $15,000 to $30,000 per 1,000 square feet. It’s shallower and lighter than an intensive roof, with a depth of about 6 to 10 inches.
This type of green roof is right in the middle: it requires more maintenance than an extensive green roof, but not as much as an intensive green roof. Likewise, it can support more plant life (and a wider variety) than extensive green roofs, but not as much as intensive ones.
Extensive Green Roof
Extensive is the most affordable type of green roof to install, at approximately $10,000 to $20,000 per 1,000 square feet. It’s cheaper than others because it has a shallow soil layer of about 4 to 7 inches.
An extensive green roof is a layer of vegetation placed over a waterproof membrane on a flat or low-sloped rooftop. The vegetation is usually shallow-rooted and requires minimal maintenance.
Blue-Green Roof
This type of green roof typically costs around $13,000 to $32,500 per 1,000 square feet. A blue-green roof incorporates stormwater management and collection (that’s the blue) with a rooftop garden (that’s the green). A blue-green roof is a one-two punch for efficiency, helping conserve both water and energy.
Biosolar Green Roof
A biosolar green roof typically costs around $25,000 to $35,000 per 1,000 square feet. This type of green roof combines vegetation with solar panels or shingles to insulate your home and generate clean electricity.
Other Factors That Affect Cost
The cost of green roof installation depends on many unique factors. In this section, we will explore some of them.
Type of Vegetation
Depending on the soil depth of your green roof system, you have a lot of options when it comes to choosing vegetation for your rooftop garden. Different types of plants have unique upfront costs and need specific levels of maintenance in the long run.
Plant types you can use on a green roof include:
- Sedum
- Moss
- Grasses
- Herbs
- Flowers
- Shrubs
- Small trees
If you want to use a more diverse range of plants, it will cost more than if you just use one type. Larger plants like trees and shrubs will also cost more to purchase and maintain than low-maintenance options like sedum and moss.
Growing Media
A growing media is a material used to support plant growth in an artificial environment (such as a green roof). It is typically a mixture of soil, sand, and organic matter. It is usually placed in a container used to provide nutrients and water to plants.
There are two types of growing media used in green roof installation:
- Inorganic growing media: Made of inorganic materials such as sand, gravel, pebbles, perlite, or crushed stone
- Organic growing media: Made of organic materials such as compost, bark, or peat moss
Soil-based media are generally more expensive, but they offer better drainage and aeration, which can be important factors in hot, dry climates. The type of media used and the amount of vegetation will affect both the upfront and maintenance costs of your green roof.
Roof Accessibility
If your roof is difficult to access, it will be harder and more time-consuming to install a green roof, which means you’ll spend more on labor costs. For instance, if your roof has a steep pitch, or your home is multiple stories, your overall cost will increase because of the extra work and risk involved in the installation.
Roofing Permits
Pretty much any roofing project is going to require a permit. Depending on your municipality, the permit fee can range from about $200 to $500.
However, permits may not be required in some areas. If you’re not sure whether or not a permit is required for roofing where you live, ask a local roofing contractor or city official.
Green Roof Maintenance
Annual maintenance costs for a green roof range between $0.75 and $1.50 per square foot (according to the EPA). Green roofs require periodic monitoring for debris and weeds, and the drainage system should be checked regularly to ensure it is functioning properly.
A properly installed green roof has a life expectancy of 40 years or more with proper maintenance, and those maintenance costs are often offset by the energy savings a green roof can provide.
Related Services
When you get your new green roof installed, you may find your roof needs other services, such as general repairs or drainage installation. While you’re at it, you might also decide to make your home more eco-friendly and energy-efficient with solar panels or solar shingles.
Here’s how much these additional services could cost you.
Roofing Repair Cost
The average cost of repairing a roof typically falls between about $350 and $1,190. However, the cost can vary depending on the type of roof, the size of the roof, the extent of the damage, and the location. In general, the cost of repairs is higher in 2023 due to inflation and the rising cost of materials.
Drainage Installation Cost
The cost of installing a drainage system for a green roof can vary depending on the size of the roof, the type of drainage system, and the location. In general, a roof drainage system will cost between $2,270 and $5,330 per 100 linear feet, labor and materials included.
Solar Panels Cost
Solar panels are becoming increasingly popular as a source of renewable energy, as they offer a clean and sustainable way to generate power. The average cost of a solar panel system installed is about $20,000. The cost of solar panels has been falling in recent years, making them more affordable for homeowners and businesses.
Solar Shingles Cost
If you’re interested in eco-friendly solar power, a solar roof, aka solar shingles, is another option. The cost of solar shingles is around $40,000 to $60,000 for a standard project.
Unlike traditional solar panels, solar shingles are made of a thin layer of solar material that is attached to a roofing shingle. Solar shingles are less obtrusive than solar panels because they look like regular shingles, but they’re significantly more expensive because they’re a newer technology.
Cost of a Green Roof by Location
The cost of a green roof will vary depending on your geographical location. For example, a green roof in Los Angeles will likely cost more than one in a smaller town like Winslow, Arizona due to the higher cost of labor and materials in the city.
Climate Condition
In warm climates, green roofs can help to keep buildings cooler, which can lead to lower energy costs. In cold climates, green roofs provide insulation in winter, which can also lead to lower energy costs. Because roofs in warm climates require less insulation, they may cost less to install.
Keep in mind that climate also determines the kinds of plants you can include in your green roof and how much maintenance they’ll need. For instance, if you live in the arid Southwest US, you’ll need to choose drought-resistant plants that can survive without much rain.
Government Incentives and Subventions
The government offers incentives and subventions (aka grants) for installing a green roof in some cases. Incentives are typically in the form of tax breaks or rebates, while subventions are direct financial assistance from the government. These programs have helped to make green roofs more affordable for both commercial and residential applications.
Incentives can cover up to 30% of the cost of a green roof. Subventions are also available in some areas, which can help offset the out-of-pocket cost of installing a green roof. These subsidies are usually available for both new construction and retrofits.
FAQ About Green Roof Installation
No roofing job is a do-it-yourself project, especially a more complicated project like a green roof. Green roofs can be complex systems, and proper installation is critical to ensuring that they function as intended. As such, green roof installation should only be performed by experienced professionals.
A green roof is a type of roofing that incorporates vegetation and a growing medium, planted on top of a waterproof membrane.
Green roofs can last for 40 to 50 years with proper maintenance.
Green roofs require weeding approximately every 2 to 3 months and fertilizer applications once or twice a year to keep the plants healthy. Adequate watering is also crucial for the overall health of the vegetated roof, although you should choose plants native to your area that will get all the water they need from rainfall.
Green roofs are suitable for most homes, but it is important to consult with a professional to make sure your home can support the weight of a green roof.
There are a variety of plants used on green roofs. These include sedums, wildflowers, herbs, ferns, sempervivum, moss, grasses, and shrubs.
There are a few things to consider when choosing plants for your green roof:
● Local climate: Choose plants that can withstand the temperature extremes and precipitation of your area.
● Amount of sunlight: Choose plants that can tolerate the amount of sun or shade that your roof gets.
● Weight: Choose plants that are not too heavy for your roof.
Green roofs can be challenging to install, as they require a waterproof layer and a drainage system. Additionally, green roofs can be heavy, so it is important to make sure that the structure of your building can support the weight.
In addition to reducing energy costs, green roofs can also:
● Combat the effects of climate change
● Improve stormwater management
● Provide excellent insulation
● Improve air quality
● Provide shade and evaporative cooling for buildings
● Create a more aesthetically pleasing environment
● Create a habitat for local wildlife
These are the main components of a green roof system:
● Plants: While some green roof designs come with pre-planted vegetation, others require the homeowner to purchase and plant the vegetation themselves.
● Plant trays: A plant tray, aka modular roof tray, is a type of container used to grow plants, typically on a green roof. Plant trays come in a variety of sizes and can be made from a variety of materials, including plastic, metal, and wood.
● Substrates: A substrate is a material that provides a surface on which plants can grow. There are a variety of substrates that can be used for green roofs, including but not limited to gravel, peat moss, coconut fiber, expanded clay pebbles, and compost.
● Waterproof membrane: The waterproof membrane protects against water damage and leakage. PVC and TPO membranes are the most common types used for green roofs, with PVC being the more expensive option. EPDM is another type of waterproofing membrane that is less expensive than PVC, but it is not as durable.
● Drainage system: A drainage system is necessary to ensure that the rooftop does not become waterlogged.
● Irrigation system: The two most common irrigation systems used for green roofs are drip irrigation and spray irrigation. Drip irrigation is the most efficient and effective method, as it delivers water directly to the roots of the plants. Spray irrigation is less efficient, as it can lose water to evaporation and wind.*
*Note: Ideally, your green roof should get all the water it needs from natural rainfall. If you choose the right plants for your area, you won’t need irrigation for your rooftop garden at all.
Find a Green Roofing Pro Near You
As climate change becomes an increasingly pressing global issue, it is more important than ever to take action to reduce our carbon footprint. One way to do this is to install a green roof. Generally speaking, a green roof can cost anywhere from $15 to $50 per square foot, including labor and materials. Contact a local green roof expert to learn more.
While the cost of installing a green roof may be high, the benefits can be quite significant. By adding a green roof to your home, you can reduce energy use, help lower urban air temperatures, and protect your property from weather damage.
Main Photo Credit: Annie Spratt / Unsplash / License
