Sustainability Efforts With Green Roofs

The common sustainable solution for roofs is to opt for solar panels. It seems like the straightforward answer to eco-friendly homes. Recently, however, another option is on the rise: green roofs. This concept (also called eco-roofs, living roofs, or vegetative roofs) is not new. They have existed in Europe, especially in Germany, since the 1970s.

What Are Green Roofs?

A green roof is a layer of vegetation or plants grown on top of homes. Various types can be installed depending upon the location and slant of the roof. A green roof helps with sustainability efforts in urban areas. Although some home-owners may choose green roofs primarily for aesthetic reasons, the eco-friendly benefits remain.

How a Green Roof Promotes Sustainability

Let’s understand why green roofs are a viable solution for a sustainable future:

1. Improved water drainage

Any house or building needs a proper draining system on the roof as a way to counter flooding. Usually, a network of pipes directs the water into the sewage system. With the climate crisis at its peak and impending natural disasters, a green roof is a terrific way to naturally store water in plants and the substrate before releasing it back into the environment.

2. Increased roof lifespan 

Contrary to the popular myth that green roofs reduce roofs’ lifespan, it protects them from elements that cause decay. Every roof needs to deal with heavy rain, wind, ultraviolet rays from the sun, and extreme temperatures. The barrier of greenery helps protect the waterproof membrane underneath and ensures your rooftop’s life expectancy lasts for decades. Green roofs may double or even triple a roof’s lifespan.

3. Temperature regulation

This is the biggest advantage of green roofs over traditional ones. A typical roof can have poor insulation, which results in heat loss in winter and trapped heat during the summer. A green roof can make a massive difference by improving energy efficiency. Plants absorb the sun’s energy and reduce the roof’s temperature in the summer, while in the winter, they help with thermal efficiency by locking heat inside.

4. Improved air quality

We know urban and many residential areas lack clean air. The Environmental Protection Agency reported a 15% increase in days with unhealthy air in 2017-2018. Green roofs can help. According to a study, they can reduce 37% of sulfur dioxide, 21% of nitrous acid, and 0.2kg of dust particles / per square meter each year. Green roofs can trap carbon dioxide as well.

5. Beneficial for wildlife 

Green roofs also help support wildlife and in turn, preserve healthy habitats. Green roofs are perfect for attracting birds and other wildlife. They don’t replace ground environments, but they lead to viable improvements in the long run compared to regular roofs. Each green roof will support different habitats depending on the type of vegetation included. According to a survey in Switzerland, 11 green rooftops housed a combined total of 172 different species.

As shown in the diagram above, a sustainably built green roof is made up of layers. Critically, there is a waterproof membrane and root barrier to ensure there is no leakage. The irrigation and drainage layers take care of distributing, storing and draining excess water. The growing medium and vegetation comprise the top layer.

Challenges of Green Roofs

This is not to say having green roofs doesn’t come with challenges:

1. Higher costs than traditional roofs

Green roofs are more expensive because they are heavier and therefore need more structural support for installation. Typically, a green roof will add 50-200kg/square meter to an existing rooftop. Although some rooftops will need to be retrofitted to cope with the weight, flat roofs are often able to handle it.

2. Maintenance

Like any other garden, green roofs need regular maintenance. The purpose of having green roofs is to enjoy the benefits while giving back to nature. This requires regular tending to the plants.

Conclusion: A More Sustainable Future

There are more benefits than drawbacks to having a green roof and the drawbacks themselves are manageable. In the long run, green roof technologies not only provide home-owners and building owners with a good return on investment, but they also make way for social, economic, and environmental benefits, particularly in cities. Opt for a green roof for your home and commit to sustainability!