If you have ever wished for your home to be more beautiful, more valuable or more sustainable, then you might want to “think green.” Green walls and roofs are landscaped building surfaces that can definitely grant those three wishes at once. Turning your backyard, or even panel of your interior walls into something different and spectacular could be just the thing to liven up your home.
Green roofs are a landscape constructed on a roof and include a range of different types and applications that depend on your desired outcome. They can be small, container beds supporting trees and shrubs, or lightweight configurations of only a few centimeters in depth - or more than a hectare in size covered in succulent and herbaceous vegetation. Similarly, they can be much bigger and applied to commercial scale projects such as the California Academy of Sciences, which features a green roof over 90% of its roofing structure.
Green walls fall into two very different types. Living walls support plants through irrigated, vertical containers or felt-based structures fixed to a wall surface. Green facades use climbing plants to provide green coverage over a wall, either directly on the building surface or more commonly using a steel trellis or cable system, with plants grown in-ground or in containers that are supported across the building façade.
The research associated with green roofs and walls is increasing as efforts expand across the globe. Green roofs have been shown in a number of studies to reduce building energy budgets, slightly reducing winter heating costs, while providing more significant reductions to summer cooling. The Royal Melbourne Garden Show is a good place to find ideas for your next home landscaping project. Shows like this are a hub for new innovations that might help you decide what to do, along with expert advice.
Green roofs and walls have been shown to increase property values, partly because people like to view them, but more so because they provide more recreational and amenity uses. In one study rentals were shown to be 16% higher in buildings with green roofs compared to those without.
To capture these benefits, the City of Melbourne Council has produced a document titled the "Growing Green Guide." The guide tries to explain how to create high quality green roofs, walls and facades. It also thoroughly discusses the science behind green structures and their benefit to the wider environment. Melbourne currently does not have an extensive range of green roof sites in the central business district, but joint efforts from the Council and the University of Melbourne have been working to catalog the existing sites.
The most significant issue to consider when constructing a green structure is weight loading. A roof or wall must have the structural capacity for the mass of a green roof, wall or façade installation – both at construction and over time. Not all plants will succeed on the sometimes hostile and elevated environment of a roof or wall; and vegetation growth is strongly limited by the depth, available volume, air, water, nutrition and environmental conditions present at the site. You have been warned!
At first it can be a tiny bit overwhelming when deciding to build a green structure and therefore preparation is key. Do your research and you’ve completed half the job. It can also be a fun weekend activity for the family. And the end result will be something you can cherish and enjoy together.
How do you think we can encourage the implementation of green roofs or walls in cities?
Credit: Images by Kunal Matikiti. Data linked to sources.