Roof greening is a response to the current crisis of inaccessibility of public spaces. The garden on the roof of the house is an additional space for relaxation and improvement of the ecological situation in the city
KB Strelka has studied the potential of Moscow roofs: in the Central Administrative District of the capital alone, green roofs can create an additional 470 hectares of green areas. By area, these are four Gorky Parks.
The study highlights the environmental and economic impacts of green roofs, looks at international experience, and provides guidance for residents on how to create a rooftop garden.
In times of crisis, roofs can become a more private alternative to crowded public spaces – parks, embankments, boulevards. In addition, additional landscaping of the city will improve air quality and reduce the likelihood of flooding. Green roofs trap excess rainwater, preventing it from reaching sidewalks.
What problems of the metropolis can it solve?
1. Flooding during the rains
Moscow and other major cities can be periodically flooded during rains. This leads to difficulties in the movement of transport and the operation of urban infrastructure. Rainwater from the streets collects dust, garbage and gasoline, which end up in rivers and groundwater.
There are two ways to drain rainwater – gray and green infrastructure. Gray is storm sewers, drainage systems, locks. Green – squares, parks, rivers, rain gardens, permeable surfaces, such as eco-sidewalks. Rain gardens are special areas planted with moisture-loving plants. Green infrastructure naturally flows and retains water.
There is also the third way of water drainage is hybrid. It combines the benefits of gray and green infrastructure. Green roofs are such a hybrid.
2. Strong air heating in summer
The center of Moscow and some other areas of the city lack green areas. Norm per person – 16 square meters. m. In the Arbat area, this figure is 1,86 square meters. m. The heat in such areas is felt more strongly, and dense buildings do not make it possible to create new green areas. In summer, the temperature difference between the center and the suburbs can be up to 10 degrees. In such conditions, the effectiveness of green roofs reaches its maximum – the citizens get the park almost at home.
3. Air pollution
In cities, there is a “heat island” effect due to the disruption of the natural processes of cooling and evaporation. Dense high buildings lead to incorrect air convection, degrade its quality and lead to the formation of smog. This causes an exacerbation of chronic diseases in the townspeople. Energy costs for cooling and cleaning indoor air are also on the rise.
Green roofs could reduce heat waves across the city by 1,3 degrees. They absorb some of the city noise and carbon dioxide. The larger the area of green roofs, the stronger the effect.
4. Unstable economy
The sustainability of the urban economy depends on the development of small and medium-sized businesses and the diversity of local initiatives. On the green roof you can open a cafe, a public garden, a greenhouse, a sports or playground, a yoga studio or a library – these are new business opportunities.
In addition, green roofs help reduce thermal insulation costs – the rooms under them do not heat up so much in summer and lose less heat in winter. For irrigation and other technical needs, rainwater can be stored in tanks.
Roof garden can be done today
A rooftop garden can be made by the joint efforts of the residents of the house and divided into zones so that, if necessary, they can be used at different times and not overlap.
Where to start?
How to equip the roof?
You can use container gardening – potted plants and wooden boxes. They can grow ornamental plants, vegetables, herbs. Pallets, country chairs and tables can be used as furniture. Screenings, wood flooring or decking are well suited for covering. If there is not enough space on the roof, then containers can be placed one above the other, creating vertical gardening. For this, grapes and other types of climbing plants are suitable.
In the future, a temporary solution may become a full-fledged rooftop park. In this case, wooden boxes will rot and overgrow over time, forming natural hills. Such a solution will cost less than intensive greening of the entire roof.
In order for the green roof to overwinter and meet spring safely, it is enough to choose plants adapted to the local climate, as well as choose unpretentious and resistant species.
World experience
Cities such as Stockholm, Oslo, Ottawa, Quebec and Edmonton have similar climates to Moscow and also experience cold winters, but this does not prevent local residents from actively engaging in green roofs.
The most systematic approach was taken in London, where in ten years the area of green roofs has doubled from 71,5 hectares to 151 hectares. Not only roofs, but also walls are planted there. The city has conducted several large studies to evaluate the impact of greenery on the health of citizens and the city’s economy. It turned out that every pound spent by the authorities on landscaping brings £27 in new business, services and services for citizens., and city residents are saving nearly a billion pounds a year in health care costs thanks to improved urban ecology.
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