As Cities Become Hotter, Green Roofs Provide Cooling
23 Oct 2021
Sky Garden Ltd, CC BY-SA 4.0, via Wikimedia Commons
In recent years, as the fight against climate change turns urgent, the trend in interior design and architecture has leaned toward sustainability. Everywhere, people are asking, “how can we reduce our negative impact on the environment?” The industry has been notorious for being wasteful, but there are now efforts to improve the carbon footprint of homes. More developers and homeowners, for example, are choosing to use sustainable materials and incorporating strategies that will promote energy and water conservation.
One strategy that has been gaining popularity is the green roof.
The solution to City Heat
The green roof is not a new concept. It has been around for centuries, and it has been in use across many countries.
Cities often have very few green spaces. An aerial view of a typical urban area will likely look very gray, with a few dots of green here and there. Most buildings have asphalt, black tar, or gravel rooftops that radiate heat.
Cities are hotter than nearby rural areas because greenery is sparse. Structures that are highly concentrated create so-called “heat islands” which have higher temperatures.
A green roof is a solution to heat islands.
This strategy uses available space, especially in urban areas already crowded with concrete buildings, roads, cars, and other structures. The roof can be utilized to grow vegetation to cool.
A green roof adds another layer between the outdoors and the interiors of a building. It shields the building from the sun’s harsh rays, preventing the interior temperature from rising and becoming too hot. As a result, the people in the building would not have to rely on air conditioning to get relief from the heat.
Therefore, a green roof also leads to financial savings. In fact, according to one study, a green roof can save around $200,000 in energy costs over its lifetime. The U.S. Environmental Protection Agency says that the Chicago City Hall, which has a green roof, saves around $3,600 in energy costs annually.
Moreover, a green roof absorbs carbon dioxide, a common greenhouse gas, helping the fight against climate change. Cities have higher concentrations of carbon dioxide, forming domes that can worsen the impact of air pollutants.
Adding Green Roofs
A green roof is not just for those that have received green building certifications. Any office or retail space and house can utilize the empty roof and turn it into a garden. It is easy to install and maintain.
Moreover, it is safe. There is a false belief that a green roof adds significant weight to the roof, which later on can cause water leaks and structural problems. This is not the case. There is no evidence that green roofs are more prone to water leaks compared to traditional roofs.
However, of course, installation is not as easy as throwing plants and earth onto the roof. There are some requirements to ensure that the elements would not have an impact on the roofing material. A roof should have bituminous waterproofing to add a protective layer against moisture, but that should apply to every part of a house’s exterior. The exterior is always subjected to changing weather, including rain- and snowfall.
Ideally, the roof should also be flat or only slightly sloped. This will be able to better handle the load of a rooftop garden. Still, it is better to discuss it with an architect before making any major modification to your home.
The installation and the potential modifications needed to make the house appropriate for a green roof will cost money. You could be looking at tens of thousands of dollars in expenses. However, people still choose to create a green roof because of its environmental benefits.
It helps reduce a household’s carbon footprint, an important step toward fighting climate change. It also reduces the problem of extreme heat in cities and aids in cleansing the air of pollutants and greenhouse gases produced by vehicular traffic and manufacturing.
In addition, a green roof practically pays for its installation and maintenance. While the initial cost is high, it will enable the building to reduce heating and air conditioning by regulating indoor temperature. Owners will see their energy use decline over time.
As a bonus, a green roof adds aesthetic value to the building. Instead of a boring gray structure, there will be vibrant colors. It boosts curb appeal. Moreover, it supports life because it creates an oasis for birds, bees, butterflies, and other wild animals.
More people should consider adding a green roof to their homes because it provides numerous environmental benefits. Despite the initial cost, a green roof will also lead to money savings in the long run.