The Pros and Cons of a Green Roof

The GSA or General Service Administration currently maintains 2 million square feet of green roofs. These carefully planned rooftop gardens are popping up in almost every city.

A green roof improves the aesthetic appeal of a building and the environment of the surrounding area. Despite this, it does present potential issues.

Read our green roof guide to learn what they are and the pros and cons of installing one in your home or business.

What Is a Green Roof?

Also known as living roofs, these rooftop gardens are usually found in urban areas. They’re more complex than placing seeds in a box and should only be installed by professionals.

A full green roof system contains several layers. From top to bottom, they include:

  • Vegetation
  • A growing medium
  • An optional wind erosion layer
  • A root barrier
  • A drainage system
  • Insulation
  • Membrane protection
  • Membrane

These layers work together to keep the plants healthy, separate them from the rest of the roofing material, and provide a wide range of benefits.

There are two major types of green roof; intensive and extensive. They differ in several ways, and comparing them helps you choose the right one for your needs.

An intensive green roof includes plants, an irrigation system, and walkways and benches for humans to enjoy. This includes a foot or more of growing medium that can weigh 80-150 pounds per square foot.

An extensive green roof uses native ground cover. This makes it lighter at only 15-50 pounds per square foot. It provides the same environmental benefits and is easier to maintain.

Green Roof Benefits

A green roof provides several advantages to building owners and the cities they live in. This explains their rise in popularity.

The benefits of a green roof system include longer lifespans, stormwater management, Urban Heat Island Effect reduction, and legal incentives, as well as increased beauty, marketability, and insulation.


A green roof protects against UV or ultraviolet rays, harsh weather conditions, and other types of damage. This makes it durable and strong.

Green roof shingles last 2-3 times longer than traditional asphalt shingles used in most roofs. The green roof as a whole lasts twice as long as traditional options.

Stormwater Management

The soil and plants on a green roof naturally catch up to 50-60% of falling rainwater.

This protects your home or business from water damage and benefits the city you live in. By reducing the demand on its storm systems, it also reduces erosion and pollution.

Urban Heat Island Protection

The temperature of a green roof rarely rises above the air around it and often runs cooler. Other materials can reach 90° above the outside temperature.

Plants keep a green roof cool. During evapotranspiration, water on the leaves evaporates and cools the air. They also provide shade.

These heat-reducing benefits counter the Urban Heat Island Effect. An abundance of reflective and impermeable surfaces makes cities some of the hottest places on the planet, but a green roof can help prevent this.

Increased Insulation

In the winter, a green roof increases insulation by 25% and reduces heat loss from the wind by 50%. In the summer, it reduces energy demands by up to 75%.

These numbers can add up to a savings of up to 25% in cooling costs. You won’t have to use as much electricity or heat to maintain a comfortable home.

The increased insulation provides other benefits as well. It helps clean the air, reducing air particles by 6% and sulfur dioxide by 37%. It can even reduce sound levels by up to 10 decibels.

Legal Incentives

Several large cities such as Chicago are noticing the benefits that a green roof can provide to homeowners and the city as a whole. They provide financial benefits to anyone who installs a green roof system in their home.

You may also be able to receive credit from an organization known as LEED or Leadership in Energy and Environmental Design. They’ll give you money to help you complete your green roof project.

Increased Beauty and Marketability

A green roof makes your home more aesthetically pleasing to you and everyone who passes by. This includes any potential buyers if you choose to sell.

Adding a green roof makes your home or business more marketable and increases its value by 6-15%. Potential buyers will appreciate the effort you’ve put in to help the environment and the benefits the green roof will provide them.

Once you’ve decided what type of roof you need, check here for effective Boise Roofing solutions.

Green Roof Disadvantages

Despite their many benefits, there are reasons that not every home or business has a green roof installed. They do have a few disadvantages.

High costs and potential damage are two of the main reasons someone may not choose to install a green roof.

High Initial Costs

Turning your home into a green roof house requires a high initial investment. This can scare away potential adopters, especially if they don’t understand the benefits that make it worth the money.

An extensive green roof is more affordable than the more complex intensive variety, but it still costs an average of $8 per square foot compared to $1.25 for a typical BUR or built-up roof.

Despite the high initial costs, a green roof can save you money in the end due to benefits like reduced energy costs. You could save up to $200,000 over its lifetime.

Potential Damage

Plants grow uncontrollably, and their roots could crash into a wall or window. The weight of the plants themselves could also cause sagging and other issues.

You’ll have to pay to repair all these types of damage. To protect yourself, you may also need to purchase insurance for your green roof home. Both can be costly.

As long as you have a qualified professional install your green roof system and manage it carefully, the potential for damage remains minimal.

Where Can I Learn More?

A green roof is a carefully planned type of rooftop garden. They’re common in cities where it’s difficult to find vegetation. They’re becoming more popular as concern for the environment increases.

Green roof systems provide numerous benefits including reduced energy costs, improved insulation, and protection against the Urban Heat Island Effect. The only major disadvantages are high initial costs and the potential for damage.

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