Roof plantings date all the way back to ancient Babylon, where the hanging gardens were one of the seven wonders. Now it’s time to make way for a fresh descendant of the much-loved rooftop garden: the green roof. Just like it sounds, this is all about taking green to the next level.
This is good news for properties that lack enough terra firma for planting flowers or greenery. In urban settings and especially in metropolitan areas where vertical development far outweighs horizontal expansion, greenery can require some special accommodations.
Technically speaking, a green roof consists of layers that generally must include heat and water insulation, root protection, and soil sheets. The thickness of the layers determine the type of green roof and, consequently, the ideal choice and placement of plantings. Manufacturers add their own signature or standards in their products. For example, one manufacturer may only install roofs that are ready to be planted while some might install a roof with fully mature plantings.
A green roof is easy on the eyes, and it will beautify your property. But what you may not know is that it will also help alleviate the urban heat island effect, which is elevated temperatures in urban settings, as compared to rural areas, due to human activities and infrastructure. By adding a green roof to your property, you can contribute to lowering the temperature and reviving the air of your city.
Furthermore, many buildings that feature green roofs have the capacity to grow fruits, herbs, and vegetables. The Four Seasons hotel in Boston nests its very own “Italian Honey Lover Beehives” on their roof. This helps cross-pollinate the entire roof system to ensure a flourishing and beautiful ambiance. Honey produced from the beehives is then blended into their Bristol Lounge menu as a sweetener.
If you want to go a step further, green walls for your indoor and outdoor spaces create an even more positive vibe. However you increase the surface area of greenery, it takes the concept of going green up a notch.
Image by Katmorro via Wikimedia Commons
Whether to have an extensive or intensive roof, and the type of plants you will choose, depends upon a number of factors, including location, climate, and what level of maintenance you are willing to commit to.
While the initial cost may make you hesitate, the long term benefits can far outweigh the startup cost. A Canadian study showed a 75 percent energy-use reduction as a result of green roofs. Plus, fresh and thriving is sexier than asphalt. Consider enhancing your property with a green roof, and make it stand apart in the aerial view.
Types of green roofs
With thick layers of soil and insulation materials, intensive green roofs have thicker layers (around six inches) and are made to hold the likes of trees, shrubs, and vegetation. They greatly resemble rooftop gardens and require regular maintenance. Generally, this type of roof is accessible to the public.
Extensive rooftops require minimal maintenance, making them an ideal choice for most spaces. This type sports a much thinner layer of soil compared to its intensive counterpart. Grass, succulents such as sedum, small herbs, and vines thrive well on this roof type.
The Four Seasons hotel in Boston nests its very own beehives on their roof, helping cross-pollinate the entire roof system to ensure a flourishing and beautiful ambiance Used with permission / Four Seasons
Other benefits include:
- Significant power savings. The layers of a green roof insulate the walls and help regulate temperature, thus putting less of a load on your HVAC.
- Absorption of excess rainwater. This makes a huge difference with drainage in the event of prolonged precipitation.
A safe haven for the birds and the bees.
- Eligibility for green certificates/credits such as LEED (Leadership in Energy and Environmental Design) that may qualify for tax incentives.
- A unique and tranquil setting for your guests.
- Most importantly, a reduced carbon footprint, making you one of the good guys for the environment.
By Najook Pandya