Bring back the green to cover the gray
Flying regularly over our cities and suburbs, as many are starting to do again, I notice a distinct trend. What previously was green is rapidly turning into gray. Rapid urbanization has replaced trees and fields with concrete and metal roofs. This makes where most Filipinos live today hotter, more polluted, and prone to flooding. There is a solution — turn the gray back to green!
City planners call the rise in temperature in cities the urban heat island effect or UHI. This is made worse in the Philippine context by the lack of parks and open spaces. Even in the suburbs, the tendency for smaller and smaller lots has led to most of our subdivisions being filled with homes, but with precious little space for gardens and greenery.
Roads and driveways add to the problem, as concrete absorbs heat. This heat is released at night and makes our lives miserable. The metal and concrete roofs of our buildings and homes add to the effect. All these paving and metal also reduce the capacity of our urban and suburban land to absorb rainwater, which increases the burden on our already inefficient drainage systems, leading to flooding woes.
Instead of spending all our money on paracetamol and doctor’s fees, there is something we can do to help cure this urban malady. We can turn our roofs into gardens and bring back the green to cover the gray.
All these hard surfaces additionally reflect and amplify traffic and urban noise. No wonder hearing loss afflicts most of us urbanites. The loss of space for trees and plants also allows air pollution to spread. Nature’s filters are gone, and that is why most of us have headaches all the time.
Instead of spending all our money on paracetamol and doctor’s fees, there is something we can do to help cure this urban malady. We can turn our roofs into gardens and bring back the green to cover the gray. We can bring color back into our lives with flowering plants and also add to our health by planting edibles.
As a professional landscape architect, I design roof gardens for commercial and residential buildings. It is easier to implement this strategy for office buildings and condominium complexes because they are normally concrete structures that allow the load of soil and plants. In collaboration with engineers, we can even design roofs to hold full-sized trees. More and more developers are finding that green roofs and open spaces on top of podiums are more attractive to buyers, as well as beneficial to reduce cooling requirements inside.
It is also possible to create roof gardens for individual homes. If you are starting from scratch, you need to tell your architect or landscape architect that you want one. Your designer will then give you options of either a full garden atop your home, or large balcony areas that also allow for greenery.
Waterproofing and a good structure to support this roof garden are key. You will also need to be able to water your garden and allow for drainage underneath the planters. The good news is that the cost per square meter of roof gardens has gone down because of new technology that allows for lighter planters, drains, and even soil. Waterproofing and drip-irrigation systems have also improved, ensuring protection against leaks and making for efficient use of water. You can look to add P8,000-P10,000 per square meter aside from the cost of the basic structure for a full roof garden.
Our future can only get greener if we plant more seeds of sustainability in our homes and cities. Let’s bring more color to our current gray lives and make our world a healthier place to live in.
Renovations are a bit more challenging. It is difficult to retrofit roofs to carry gardens. The recommendation would be to expand balconies and add lightweight boxed planters and vertical greenery on the sides. Many systems for vertical greening are available. These can support ornamentals and edibles. You can grow tomatoes and peppers on your balcony walls! Vertical greening systems will cost P3,000-P5,000 per square meter. A simple espalier and a planter at the bottom will cost less but will take longer to green.
If you have existing balconies or even small roof decks, then building trellises over these can also add a lot of green to your roof. A few planters at the bottom will allow greenery to climb up. The cost of trellises is anywhere from P5,000 to P15,000 per square meter depending on how fancy you want them. When in doubt, consult a professional landscape architect.
The simplest and least expensive alternatives are window ledge planters or container-planting for balconies. Many of these are available at your local DIY store. Online sources are difficult because you can’t be sure of what you get.
So green your roofs and homes tomorrow. Our future can only get greener if we plant more seeds of sustainability in our homes and cities. Let’s bring more color to our current gray lives and make our world a healthier place to live in.
For advice or help finding a professional landscape architect, contact the Philippine Association of Landscape Architects at their Facebook page.