How Much Does a Green Roof Cost? (2024 Guide)

Highlights

• A green roof cost averages $22,000, though some homeowners spend between $12,000 and $40,000.
• The main cost factors for installing a green roof include the roof type and size, the roof pitch, the system type, labor fees, and permits.
• Installing a green roof offers a number of benefits to homeowners and the environment: improved energy efficiency, better stormwater management, extended roof life, natural wildlife habitat, and reduced noise. 
• Green roofs are complex systems that can easily be installed incorrectly, leading to leaks, poor energy efficiency, and even structural damage. Hiring a pro is the best way to go for a green roof installation project.

The conservation-minded homeowner can build a more sustainable house using new technology such as a green roof. A green roof has a thin layer of live vegetation instead of common types of shingles to offer better insulation and a more eco-friendly environment. Green roofs are starting to be more widely used on commercial, industrial, and institutional building rooftops due to a wide range of green roof benefits. The popularity of a green roof on a house is growing, with renovation projects that increase energy efficiency, insulate the home, and improve stormwater management.

According to HomeAdvisor, installing a green roof system will generally cost about $22,000, though the overall price could range from $12,000 to $40,000 depending on the type. This fluctuation in cost occurs as a result of differences among green roof homes and homeowners’ preferences in green roof sections, growing media (base materials), and vegetation types. Homeowners can find out more about these key green roof cost factors before installing a green roof. 

Key Cost Factors

When homeowners are considering whether a house with a green roof is a good idea, it’s important for them to weigh the potential benefits of this upgrade against average roof replacement costs. The high replacement cost for a green roof is one of the primary drawbacks to green roof installations. Homeowners can review common green roof cost factors, including the roof size, roof type, roof pitch, and green roof system. 

Roof Size and Type

The size of the roof is one of the most important factors to consider when homeowners are creating a budget for a green roof installation. The larger the roof, the more material will be required for the project. Similarly, the larger the roof, the longer it will take for the installers to complete the job, increasing the overall labor cost. Homeowners can expect to pay between $10 and $30 per square foot for a new green roof. 

However, the cost can vary depending on the type of green roof: biosolar, blue-green, extensive, intensive, or semi-intensive. An extensive green roof is one of the more affordable residential options available, while an intensive green roof is typically the most expensive and better suited for large-scale applications. Homeowners can work with one of the best roofing companies to determine the optimal type of green roof for the home.

Roof Pitch and Accessibility

Climbing up onto a roof can be dangerous, especially if the roof has a steep pitch that makes it difficult to maintain balance. Considering the hazards, contractors will charge more for labor to install a green roof if the home has a steep roof pitch. If the roof is difficult to access due to multiple stories or obstructions around the base of the home, then the cost of the project will go up. 

Additionally, the pitch of the roof can impact the homeowner’s choice of green roofing systems. Modular green roofing systems are not suitable on roofs with a slope that is steeper than 20 percent to 30 percent (11 degrees to 16 degrees). The trays can easily slip on a steep slope with the added weight of the growing media and vegetation. Before starting this job, homeowners will want to consider the options available for the existing home structure.

Green Roof System

When planning a green roof installation project, the homeowner will need to decide on the right green roof system for the home. Their choices include modular tray systems or built-in green roof root barriers.

• Modular tray green roof systems have an average cost of $10 to $30 per square foot. They are one of the easier types to install as long as the roof has a suitable pitch. This type of green roof system consists of a series of trays that hold the growing media and selected vegetation. Homeowners can remove a single tray at a time to maintain it or add new vegetation.

• Built-in green roof root barrier systems offer a more permanent, customizable alternative to modular tray systems, though they can cost about $20 to $35 per square foot. Built-in systems generally come as a lightweight, rolled-up mat measuring about 100 to 1,400 square feet on average. They’re more suitable for steeply pitched roofs and are lighter than modular systems. The mats are installed over several protective waterproof layers that are applied directly on top of the roof for a semi-permanent installation.

Labor and Permits

The labor involved with a green roofing installation job ranges from about $5 to $10 per square foot, which can become costly for a large roof. Costs can vary based on location and project difficulty and may also differ among roofing companies. Green roof installation companies will be able to suggest appropriate green roof systems for the home and ideal vegetation that grows well in the local climate. 

Homeowners can also speak to the roofing company or the local permit office to determine if a permit will be required for the job. In most cases, the roofing company will handle permit acquisition, though it’s recommended that homeowners verify to ensure that everyone is on the same page. On average, permit fees for this type of work will range from about $200 to $500. 

Vegetation Type

Adding a green roof can improve the aesthetic appeal of the home, since homeowners have a wide assortment of vegetation to choose from. They can even choose certain designs and color schemes they prefer to have installed. The cost of the project can be affected by the type of vegetation. 

Moss and grasses are relatively low cost, while shrubs or even small trees can cost more for a residential installation. Also, the cost will increase as the diversity of plants increases, so it can be more cost-effective to opt for just one or two varieties of vegetation.

Growing Media

Homeowners will also want to consider the type of growing media that they use to support the plant growth. Generally, growing media is made up of a mixture of soil, sand, and organic matter that is then either placed in trays or rolled out as a green roof root barrier. Green roof installers can help homeowners decide on the best roof underlayments, shingles, waterproofing materials, and growing media that is right for the home.

Inorganic growing media, like sand, gravel, pebbles, perlite, or crushed stone, are common choices since they don’t require a lot of maintenance and cost less than organic growing media. Organic growing media, like compost, bark, or peat moss, are more expensive and require a higher level of maintenance. Still, organic growing media also offers better drainage and aeration to help protect the home. 

Annual Maintenance

Like most elements of a home and property, a green roof will require regular maintenance to keep it in good condition for years to come. Homeowners can get green roof cleaning and maintenance services by hiring green roof gardening professionals, though some homeowners may choose to handle all of the green roof maintenance on their own. DIY maintenance is typically easier to do with a modular green roof system that has trays that can be removed from the roof.

On average, the maintenance and roof cleaning costs will range from about $0.75 to $2.00 per square foot for an extensive green roof and about $1.25 to $2.00 per square foot for an intensive green roof. Homeowners can ask the green roof installers whether they offer ongoing maintenance packages or know of any reputable companies in the area that offer these services. The best roof cleaning services (like Window Gang or Window Genie) may be able to clean a green roof or recommend a company for the homeowner to hire.

Additional Costs and Considerations

A green roof installation is a costly upgrade, so before starting this project, homeowners may want to consider the other options that are available, like a cool roof or a modular green roof. There could be extra project features, like built-in irrigation systems or solar panel systems, which come with their own costs for added material and labor.

Green Roof vs. Conventional Roof

Most homes have a conventional roof that is designed to protect the home from sun, rain, sleet, hail, snow, ice, wind, and outdoor temperatures. Traditional roofs are a popular choice that have worked for generations and have a lower price point of $4.35 to $11 per square foot.

However, while a built-in green roof can cost between $10 and $30 per square foot, it comes with a list of benefits that a conventional roof cannot match. Some green roof benefits included reduced noise pollution, increased energy efficiency, and a better ROI (return on investment). With this in mind, investing in a green roof is an excellent option for long-term savings and increased property value. 

Green Roof vs. Cool Roof

A built-in green roof uses living plants and vegetation to shelter the home from the elements. But at a cost of $20 to $35 per square foot, a built-in system may not seem like the most appealing option for cost-conscious homeowners. Still, opting for a green roof installation can also help to manage the flow of stormwater around the home, provide extra space for local wildlife, and extend the life of the roof by almost twice as long as a conventional roof.

A cool roof can be a good alternative option that has a less expensive up-front cost and offers moderate protection from UV radiation and heat. Contractors will install reflective materials on the roof to deflect the sun’s rays and keep the home cooler naturally. Cool roofs are especially popular in areas with warmer climates, since they help to keep the home cool and reduce the energy costs for the home.

Modular Roof vs. Built-In Roof

The two main types of green roof systems include modular and built-in green roofs. A modular green roof system comes in removable trays, allowing the homeowner to take individual trays off the roof for extra care, replanting, or regular maintenance. It ranges in cost from about $10 to $30 per square foot, while a built-in green roof will cost between $20 to $35 per square foot. 

For a built-in, Installers will add a vapor control layer, thermal insulation, roofing membrane, waterproof barrier, and green roof root barrier before finally installing the drainage, filtration, growing media, and vegetation. Built-in green roofs are more permanent and customizable.

Roof Inspection

Before installing a green roof, homeowners will want to have the existing roof inspected to determine if there are any roof repair costs that need attention first. Additionally, a roof inspection is advised after the green roof installation is complete to ensure that the green roof was installed according to the local codes and regulations.

Typically, a roofing inspection costs about $215, depending on the size of the roof and the extent of the inspection. The initial inspection can help spot any problem areas and identify if any additional structural supports will be required before a green roof can be installed. This is an essential step that most green roof installation companies will insist on to ensure that the home can hold the weight of the new green roof without bowing, bending, or collapsing. 

Irrigation System Installation

A built-in irrigation system can be used to keep the green roof lush and lively, though not all green roofs require this feature. Basic extensive green roofs, which are popular for residential homes, generally don’t  require watering. However, semi-intensive and intensive roofs typically have vegetation that will need regular watering.

The installation of an irrigation system can reduce the amount of hands-on maintenance needed for the upkeep, but it’s also important to have a proper drainage system installed to prevent puddles of water from forming on top of the roof. Drainage is included as a part of the green roof installation process, though it’s recommended to review irrigation and drainage options before beginning.

Solar Panel System Installation

Solar panels are typically used for biosolar green roofs in combination with the vegetation. This is a popular choice for large apartment buildings, condo buildings, commercial spaces, and institutional buildings, such as at universities and colleges. Most residential homes are not built to support both a green roof and a solar panel system, so homeowners will want to discuss this option carefully with a contractor. On average, solar panels cost $26,579. Many of the best solar companies (like Tesla) offer financing to help homeowners afford solar panels for their homes.

Tax Rebates and Incentives

Green roofs offer benefits to the home and the environment, so many local, state, and federal government agencies offer tax rebates and incentives for this home upgrade. Depending on where the home is located, green roof incentives may cover up to 30 percent of the cost to install a green roof.

Local policy incentives can also include stormwater fee reductions, tax abatements, and direct financial incentives to help offset the high initial cost of installing a green roof. These subsidies can be used for both new constructions and retrofit installations. Homeowners can contact local housing or energy organizations to determine if the home is eligible for any rebates or incentives.

Types of Green Roofs

The cost to install a green roof depends on a range of factors that the homeowner may not have a lot of control over, such as the size or pitch of the roof. However, homeowners can choose from among five common types of green roofs: biosolar, blue-green, extensive, intensive, and semi-intensive. 

Type of Green Roof	Average Cost (Materials and Labor)
Biosolar	$25 to $35 per square foot
Blue-green	$25 to $35 per square foot
Extensive	$10 to $20 per square foot
Intensive	$20 to $40 per square foot
Semi-intensive	$15 to $30 per square foot

Biosolar

A biosolar green roof combines the eco-friendly benefits of a green roof and a solar panel system. However, due to this combination, a biosolar roof is one of the more expensive choices, since the homeowner will need to pay for both the green roof installation and the solar panels. 

However, if a homeowner is especially drawn to the idea, they’ll need to get confirmation from a pro that the existing house structure will be able to support the weight. It costs about $25 to $35 per square feet for the green roof installation and an additional $250 to $600 per panel. Due to the cost and weight considerations, biosolar green roofs are generally installed only on larger commercial, industrial, and institutional buildings.

Blue-Green

Unlike condos and apartment buildings, most residential homes do not have a flat concrete roof, which is what’s generally required to install a blue-green roof. This type of green roof helps manage stormwater and is ideal for areas that get heavy rainfall. Blue-green roofs combine rain storage techniques with green roof technology to help store and manage excess water.

Homeowners will have fewer vegetation options to choose from due to the space that is taken up by the rain storage and management systems. Homeowners can plan to spend about $25 to $35 per square foot for a blue-green roof project.

Extensive

The most common type of green roof is classified as “extensive.” This style is the most affordable, ranging from just $10 to $20 per square foot. Another reason extensive green roofs are a more popular choice for residential homes is that they weigh less overall than intensive or semi-intensive green roofs. 

Generally, existing residential roofs are not made to bear a significant amount of weight, so  intensive or semi-intensive green roofs may not be an option. Instead, homeowners can invest in a lightweight extensive green roof, which is essentially maintenance-free and does not require irrigation to keep the vegetation lush and healthy. The system naturally collects and reuses water thanks to the design.

Intensive

The most expensive option commonly used for residential homes is an intensive green roof system. This type of green roof costs between $25 and $40 per square foot due to the thick, heavy layers of soil and the extra time necessary to properly install the green roof materials, apply the growing media, and plant the selected vegetation.

Intensive green roofs also allow for the most customization, so homeowners can get the exact look and feel they are going for. An intensive green roof weighs significantly more than an extensive green roof, which means that the home needs to be able to support the extra weight without bending, bowing, or buckling. Additionally, this type of green roof requires a lot more care, maintenance, and irrigation than an extensive green roof.

Semi-Intensive

Homeowners can choose a semi-intensive green roof, as long as the home can structurally support the weight. Semi-intensive green roofs weigh more than extensive green roofs, but not as much as intensive green roofs. Similarly, the price for this type of green roof falls between extensive and intensive, with a range of $15 to $30 per square foot. 

In many semi-intensive green roof designs, the installer will use modular containers with a variety of plants instead of a built-in green roof system. When constructed on larger commercial roofs, semi-intensive green roofs can have a sculpted appearance with premade paths for visitors to traverse. This type of green roof requires ongoing maintenance and irrigation to keep the vegetation healthy and attractive.

Benefits of Installing a Green Roof

Installing a green roof comes with many cost-benefit considerations. As long as the initial price and the ongoing maintenance are feasible, there are several impressive benefits that can be gained by investing in a green roof for the home. Homeowners are encouraged to consider the benefits of installing a green roof when deciding if this is the right roofing option for them or if a conventional roof is better.

Improved Energy Efficiency

A house is not designed to be completely airtight. In fact, proper airflow is essential for a healthy environment in the home. However, a poorly sealed or insulated house lets heat escape through the walls and the roof of the home in the winter. And heat can enter through the same avenues during the summer, forcing the heating and cooling system to operate more often until the optimal interior temperature is restored.

A great benefit to installing a living green roof is that the layers of green roof material, growing media, and vegetation insulate the top of the home. This reduces the transfer of heat and improves the overall energy efficiency of the household, which cuts down on heating and cooling bills.

Stormwater Management

When the home is located in a city or town that gets an excessive amount of rain and other precipitation, proper drainage can be a big problem. Ideally, rainwater is redirected through the gutters to move away from the home, but if the rain is too heavy, then it may overflow and soak into the ground around the foundation of the house. 

Excess water in the soil around the home can put pressure on the foundation, leading to leaks and water damage. The vegetation and growing media of a green roof help to protect the home and better manage the stormwater. Additionally, a green roof system will typically have drainage built in, which can be used to handle high levels of rain and meltwater. 

Extended Roof Life

When a roof starts to fail, water can seep into the home, causing mold growth, rot, and water damage. Homeowners are advised to take action as soon as possible to mitigate the damage, but in many cases, the problem goes unseen and unnoticed for far too long. When this occurs, the home will require substantial repairs, such as to the roof. 

On average, homeowners can expect a roof to last about 25 to 50 years with proper care and maintenance. If the homeowner installs a green roof, the roof will last between 40 and 50 years. For many homeowners, this means they will need to invest in a green roof only once in their lifetime, making it a worthwhile purchase for a home. 

Natural Habitat for Wildlife

Vast, sprawling urban communities are developed on top of the natural habit of many different wildlife species, like birds, bees, and other common animals. However, by installing a green roof on a residential property, homeowners can provide some displaced wildlife an otherwise unused space to live and thrive. Revitalizing a habitat for a few species will attract other wildlife in the area, increasing the biodiversity within the local neighborhood. This type of equilibrium offers an alternative to competing for space and resources with the other species that share the planet.

Reduced Noise

Homeowners who live near main intersections or along main streets often experience a high volume of audible traffic. Similarly, the sounds of neighbors and pets can interfere with sleep or distract homeowners and other residents who are working from home. 

Fortunately, the layers of green roof material, growing media, and vegetation aren’t just effective at reducing the transfer of heat; they can also be used to insulate against noise pollution. A sound reduction of up to 40 to 50 decibels is possible with a green roof. 

DIY vs. Hiring a Professional 

There are a wide range of home renovation and remodeling jobs that can be handled by an experienced DIYer with enough time on their hands, but there are some jobs that are best left to the professionals. Green roof installations are relatively new to the residential market, which limits the amount of hands-on knowledge that is available to the general public. With this in mind, very few DIYers have the necessary skills, knowledge, and training to complete a green roof installation successfully and safely.

If a green roof is not properly installed, the moisture retention of the plants can cause damage to the home, including leaks, rot, water damage, and mold growth. Instead of taking on the installation as a DIY project, homeowners are encouraged to spend some time researching local roofing companies that may offer green roof installations. The right company will know how to assess the roof’s structure to ensure that the preferred type of green roof will work. They’ll also have the tools and access to materials that homeowners might not have.

Not all roofing companies that offer this service have extensive experience with green roofs, so it’s important for homeowners to vet each company’s qualifications and get references from previous customers. This will help narrow down the selection and determine which green roof installation company is best for the job and the budget. 

How to Save Money

A green roof can be an excellent choice to help reduce overall energy costs, manage stormwater, and even extend the life of the roof. However, one of the primary drawbacks of installing a green roof is the expense. Homeowners can consider these options for saving money on green roof costs.

• Get multiple quotes. One of the easiest ways to cut down on the cost is to go with a company that has a lower labor rate or material cost and a track record of quality installations.
  
• Choose a modular green roof system. Modular green roofs are easier to install, and a lot of the work can be completed on the ground rather than on the roof.

• Install an extensive green roof. While intensive green roofs offer a wide range of vegetation and growing media options, extensive green roofs are significantly less expensive, making them a more realistic choice for cost-conscious residential upgrades.
  
• DIY maintenance work. Homeowners can keep ongoing costs low by taking care of green roof maintenance on their own instead of paying for professional maintenance.
  
• Apply for rebates and incentives. Some local, state, and federal government organizations can help to balance the cost of the green roof installation with rebates and incentive programs. 

Questions to Ask a Pro

Green roofs are a relatively new option for residential homes, so there is a lot of information the average homeowner may not know. Before, during, and after the installation of a new green roof, it’s recommended that homeowners ask as many questions about the process as possible. The information will help provide an understanding of the project scope, the benefits, the styles available, expected costs, maintenance requirements, and any guarantees.

• How long have you installed green roofs?
• Are you licensed, bonded, and insured?
• Can I see a portfolio of previously complete projects?
• Do you have references available?
• What does the installation process involve?
• Are there tax benefits to installing a green roof?
• What are the types of green roofs?
• Which is the best type of green roof for my home?
• Is a cool roof better for my needs than a green roof?
• What are the advantages of a green roof?
• Can a green roof be installed on all types of roofing material?
• Can I walk on the green roof?
• Will the green roof hold up in the winter?
• Is a green roof waterproof?
• Will the green roof have an insulating effect?
• Do you offer maintenance packages?
• How much does a green roof weigh?
• Will my roof need to be reinforced?
• Which plants can be used on the type of green roof I want to have?
• What is the maximum pitch possible for a green roof?
• Do I have to mow my green roof?
• How often will my roof need to be weeded and watered?
• How long will the project take?
• Do you offer any warranties or guarantees?

FAQs

Homeowners are encouraged to learn as much as possible about green roofing before deciding whether it’s a good option for them. The answers to some of the most frequently asked questions about green roof installation will shed more light on what a green roof can offer and the potential drawbacks of a green roof project. 

Article Sources

HomeAdvisor, Fixr, Forbes, Roof Gnome, Life Hacket