On June 6, 2020, the world celebrated the very first World Green Roof Day or #WGRD, an event that aims to celebrate green roofs all over the world and how they benefit people and the environment. Initiated by Chris Bridgman, the owner of a UK-based landscape construction company, the #WGRD2020 aims to promote green roofing in every city to adjust to climate change. It also ushers in the Green Roofing Association, a group of individuals and businesses who are green roof aficionados, investors, and enablers.
What Is a Green Roof?
In the simplest of terms, a green roof (also called a living roof) is a roof that’s partially or entirely planted over, in some cases, even around chimneys, dormer windows, and seamless rain gutter systems. There are many reasons why homes or buildings install green roofing systems. Let’s look at the primary benefits.
Lessens Urban Heat
The study, “Thermal insulation and cost-effectiveness of green-roof systems: An empirical study in Hong Kong,” explores the effectiveness of using green roofs in densely populated and highly urbanized cities such as Hong Kong. Conducting surveys, case studies, and interviews, the team found that green roofs can lower inside temperature to up to 3.4 C (34.12 F). The multiple roofing layers provided by green roofs insulate the building and protect ceiling materials from UV rays by up to 60%.
Researchers learned, however, that while most respondents want to have green roofs, they are not willing to invest in it. They expect the government to take the lead.
Promotes Energy Efficiency
It follows that when green roofs insulate buildings, these layers help lower the demand for energy consumption needed to cool indoor temperatures by as much as 10% in some buildings. Based on a study by the University of Michigan, the low maintenance and energy cost you gain from green roofing results in more than 50% return on investment. Even with a high initial cashout for green roof installation, users can save on energy bills in the long term. The study discovered that a building with two to three stories could save up to 25 percent on energy costs in the summer.
Improves Air Quality
The absence or lack of plants and trees in cities often cause air pollution. But cities have a lot of buildings with practically unused roofs, which can be turned into gardens and vegetable patches. A Portland State University research, published in Building and Environment, learned that green roofs are instrumental in improving indoor air quality in commercial buildings.
Testing the air entering two buildings through air vents from the roof, the researchers measured a significantly lower amount of ozone in the green-roofed structure than the one with a regular roof. They also found that vegetation trapped air particles and prevented them from entering the building. These studies, however, also said one green roof could do very little to sanitize the air or the environment; an entire community of green roofs will bring more significant results.
Creates Local Food Sources and Ensures Biodiversity
Installing green roofs is an opportunity to cultivate healthy food sources that will help households save on food costs. By planting vegetables on the roof, homes can be self-sustaining, relying less on retail food supplies and ensuring food-readiness in situations such as the recent lockdowns.
Multiple green roofing systems bring biodiversity as well, providing a healthy ecosystem, which might be the solution we need to fight the coronavirus pandemic problem.
All these rewards raise the question: Should green roofing be mandatory? Many countries have started to implement their clean and green initiatives that have achieved positive results in terms of cleaner environments and cost savings. But green roofing is still a long way from being a culture and convention. This event can perhaps attract more people to its cause.