Every post this week has been about roofs, we looked at white, blue, and soy roofs. Let’s not forget about the classic green roof.
The classic green roof is tried and true with hundreds, if not thousands, of proven efficacy. Green roofs retain water, cool buildings, and improve the planet. When it comes to green roofs a new study has revealed that the bigger the installation the greater the effects a green roof has.
•Intensive green roofs achieve the greatest air temperature and PET reduction in the low-rise buildings.
•Green roofs reduce outdoor air temperature and buildings’ cooling energy above buildings up to 30 m height.
•Green roofs strongly reduce buildings’ cooling energy demand in the extremely dense built-up areas.
•Intensive green roofs attain the best impact on outdoor air temperature and buildings’ cooling energy demand reduction.
•Economic aspect favors the extensive green roofs usage to reduce cooling energy in the buildings.
Green roofs are great for collecting water and cooling neighbourhoods, they are also useful for feeding their local communities. In the densely built urban environment of Hong Kong there is a network of green roofs that used for farming. These farms are used to grow crops sold in local stores and to encourage the people of Hong Kong to get their hands dirty and understand where their food comes from.
Here the team tell me about their other goal: education. By running regular workshops, the team hope that Hong Kong’s city-dwellers will become a little more aware of the resources needed to grow the food they are eating. Pointing to a bed of broccoli, for instance, Hong remembers one recent group who had never seen the whole plant. “They didn’t realise that the florets that we eat are actually quite limited,” she says. “And if you look at the quantity we see in the supermarket, you begin to see how much space we would need to grow that,” she says.
Ultimately, Tsui’s dream is that a restful break on a rooftop farm will become ingrained in everyone’s daily routine. “I use the analogy of coffee,” says Tsui – something that was once a luxury, but which became a lifestyle, through sheer convenience. If he had his way, a trip to the farm would be as essential as a morning caffeine fix. “We do have a mission, in a way – to make farming cool.”
Green roofs are pretty great because they assist in flood prevention and can grow crops. Indeed, green roofs are growing in popularity around the world because they are great for cleaning air and cooling cities too! It’s almost as if many urban problems can be solved by converting unused space into usable green environs.
In Chicago green roofs are being planted throughout the city and are proving to be very beneficial. The New Republic decided to reveal the mini-paradises that these small roofs can create.
By 2050, 2.5 billion more people are projected to leave the countryside for the city; in the United States alone, urban land will more than double by 2100. Faced with what scientists call “the urban heat island effect,” cities around the world are encouraging the development of roof gardens. These blankets of wildflowers, grasses, and sometimes even vegetables reduce water runoff, absorb carbon dioxide, and lower temperatures. Chicago is home to the world’s largest rooftop farm: The two acres of land atop a soap factory supply a million pounds of vegetables a year.
Green roofs or solar panels are now required on all new commercial buildings in the country of France. This is great because now buildings can have either a zero energy impact or contribute to their local environment.
Rooftops on new buildings built in commercial zones in France must either be partially covered in plants or solar panels, under a law approved on Thursday.
Green roofs have an isolating effect, helping reduce the amount of energy needed to heat a building in winter and cool it in summer
Green roofs are great! They help alleviate a lot of issues that arise in urban living while making cities more beautiful. There is growing interest in making sure that urban green roofs take off and it looks like it is working.
While other countries like Germany have been using green roofs since the 1980’s, North America has been playing catch up. Toronto, however, is a city enamoured with renewable energy and sustainability. Ryerson’s engineering building on Church St., the new Forensic Services and Coroner’s Complex and Toronto City Hall are all notable examples of green roof early adopters.
A pioneer in North America, the city requires all new builds with a minimum gross floor area of 2,000m2 to include a portion of vegetation on roof surfaces. It also offers a grant of up to $75/square metre to offset the cost of green-roof installation. Similar incentive programs are being instated in Washington DC, NYC and Chicago, but Toronto is the first to actually mandate builders to include a vegetated roof – or face a hefty fine.
And with good reason. Green roofs divert waste, help manage storm water, moderate ‘urban heat island’ effects and improve air quality. They also reduce noise and can save significant amounts of money. In a warehouse complex, for example, the evaporation characteristics of a green roof can lower the inside temperature from between three to five degrees celsius.