April 15, 2019 – Published in Design & Decor Spring 2019 issue
A breath of fresh air to highlight your home?
Words Vanya Veras
Maltese homes often have a large area of unused real estate: their roofs. Through the roofs comes the heat of summer and the cold of winter, our only tools to date to combat these being waterproofing and air-conditioning.
A green roof, well actually, a Mediterranean rooftop ecosystem, changes all of that.
Vivacity Ltd was set up to bring Malta a stunning innovation, created in our neighbouring country Greece. This technique for greening roofs gives the building a useable green space on the otherwise barren roof, natural insulation against the heat and cold as well as a natural cooling system in summer which dramatically reduces the need for air-conditioning. So the occupants feel more comfortable, spend less on heating and cooling and have all the benefits of a fully organic garden complete with herbs and flowering plants from Mediterranean nature.
In addition to the benefits enjoyed by the occupants, this green roofing system is quite a marvel. It is very light at only 50kg/m2 when watered and so applicable to any roof that can be walked on. It is modular so shapes can easily be made with it, to make space for areas of decking: for a table and chairs, a barbecue, the washing line…
As this system copies the surrounding countryside’s ecosystem, it also survives with very little water. In fact, it suffers if watered too much! For a Mediterranean island such as Malta whose drinking water comes from the sea through energy intensive, costly reverse osmosis, this is a very important consideration.
Over the last few years, really very recently, Malta’s population has exploded and with it, construction ranging from mini towers of tiny flats to luxurious towers and hotels. All of this construction has various impacts but I will address only two: dust and heat.
During construction there is a great deal of dust from digging into the Maltese limestone. On its own this causes lung problems and asthma attacks however emitted into air polluted by passing traffic, its effects on health are severely exacerbated. The more living plants in such areas, the greater the surface area of leaves and soil to which the dust can adhere, taking it out of the air. The living plants will also combat the air pollution by taking up CO2 and releasing oxygen, so improving the health of the surrounding residents.
The heat of summer can be crippling, particularly for the very young and elderly but also for those trying to do a day’s work. Air-conditioning units work at full power all day, trying to cool the air of buildings with walls burning with the stored heat of the sun. On the top floor it simply does not work in the midday sun, under a concrete roof; because the roof surface is 80C by 10am for most of the year. Under the rooftop ecosystem it does not exceed 35C all day. For the people living under that roof, however high, and paying the electricity bill the immediate benefits can easily be understood. However there are benefits to those outside as well. By not cooling the interior as much with air-conditioning, less exhaust heat is emitted into the surrounding air. If the roofs of a whole urban block are greened, the ambient temperature in that block can be lowered by as much as 5C!
The natural cooling effect of the plants has a virtuous feedback effect: cooling the building structure without creating heat, rather that the negative loop effect of burning fossil fuels to make electricity, to power units which cool inside but heat outside, further increasing demand for cooling.
There’s a beautiful addition to this story. As this green roof uses plants which occur naturally in Mediterranean climates, they provide food and shelter for other plants and wildlife: the owner provides a service to the local ecosystem, to biodiversity and the wider human population. It fast becomes a self-sustaining butterfly garden and a haven of peace and tranquillity.