Wednesday, September 20, 2017

GREENITIATIVES

Vertically verdant

 

Green walls or vertical gardens can be considered as a viable alternative to landscaping say PRADEEP and ANURADHA BARPANDE.

 

In congested urban areas, green open spaces are few and far between.  For companies, who wish to add a ‘green relief area’ to their workspaces, but cannot due to lack of space, can consider vertical gardens or green walls as a viable alternative. The concept of green walls is still at a nascent stage in India but a lot of MNCs have already introduced it in their buildings.

 

A green wall is a wall, either standing free or as a part of any building, partially or completely covered with plants. Green walls are subdivided into two categories – Green Facade and Living Wall. In facades, climbing plants are grown on a wall where in plants attach themselves directly to the surface or are grown on some supporting structure. Here, plants are always rooted in soil or some other medium at the base of the wall. Such green covering takes years to grow fully.

 

In living walls, plants are actually grown vertically in a structure attached to a wall surface but held away from it and separated from the wall by a waterproof membrane. One can grow plants directly onto a wall by using modular systems where modules are fixed directly onto the wall or freestanding structure. With the help of such systems, one can create landscapes onto the wall with the use of various plant varieties, be it perennial or seasonal. There are various systems available in the market today, which make use of fabrics that can retain water. The fabric base system requires moderate temperatures and high humidity. These are available as either modular or non-modular.

 

Choosing the right system

 

Usually, modular systems with fabric comprise a box and fabric sack and a growth medium, but modular systems sans fabric is more useful for harsh Indian climatic conditions. Moreover, less area of the system comes in contact with environmental forces and the root zone temperature remains ambient. Also the water requirement in these systems is minimal and the retention of water is more accurate. Vertical pot gardens are the most popular option for a shorter duration but the downside is that these tiny sized pots require frequent repotting, high maintenance and a complex irrigation network.  Another type of system is the wooly pocket system and such type of systems is perfect for varying ambiences ranging from humid to dry.

 

Also while choosing appropriate surfaces to set up green wall systems, it is important to note that glass and metal surfaces get heated up very quickly, leading to higher evaporation losses, hence there must be adequate space between such surfaces and the green wall systems for insulation purpose.  Ideally, green walls can be set up on sand faced plastered brick walls directly.

 

Height is also no barrier for setting up a green wall if proper access to the systems is made available for regular maintenance.  As of now ELT India has done up the highest green wall installation in Mumbai for HDFC, which stands tall at 70 feet. Moreover, there are few projects in the pipeline where ELT will set up a green wall for a residential building from the 11th floor onwards till the 29th floor.  The structural design of the system, maintenance access, type of growth media, plant varieties etc play a very important role in setting up vertical gardens at such height.

The cost of setting up these systems may vary from a meager Rs 200 to a substantial Rs 2,000 per sq ft.  The various factors affecting the costs are climatic conditions, expected end result, installation overheads, method of installation, maintenance strategy, growth medium configuration and longevity, choosing between structured and non-structured growth media, dimensions of installation, location of the green wall, choice and extent of automation, warranties and mortality replacement and extent of after sales service and more.

 

Green Relief

 

Green walls breathe life into the concrete jungle we live in by offering respite from heat. Exterior green facades can insulate the buildings and cool down the interiors thereby reducing the HVAC load and improving the air quality in the interiors. These plants can reduce temperature fluctuations at a wall’s surface from a range of 10-60° C to one of 5-30° C in turn limiting the movement of heat between building walls. The plant mass creates an ambient temperature indoors via evapotranspiration and shading; it also creates a buffer against wind in the winter months.

 

The vegetated surface provided by strategic urban greenery such as green walls and roofs will block high frequency sounds, and when constructed with a substrate or growing medium support can also block low-frequency noises. Green walls protect exterior finishes and masonry from UV radiation and rain. It can also help mitigate loss of biodiversity by providing habitat and nesting places for various bird species and pollinators.

 

Buildings that feature and promote access to vegetation have been documented as having a greater positive human health impact than those without it. Green plants have proven to mitigate the effects of harmful air pollutants such as toluene, ethyl benzene, xylene, and other volatile organic compounds, thereby improving indoor air quality and in effect, improving the workplace productivity.

 

Last but not the least, the color green is soothing to the human senses so the green walls help reclaim discarded spaces and provide an aesthetic simulation to the senses. 

 

Enough reason to convince you to go green?

 


GREEN WALL HISTORY


Although history has documented evidences of walled gardens in Egypt in BC 3000 and the Paradise Gardens of Persia, the concept has only gained popularity in recent years. Legendary French botanist, Patrick Blanc, also the author of ‘The Vertical Garden’ used the coinage to create some very inspiring and magnificent green walls. His most famous works are the Caixa Forum Museum in Spain, Quai Branly Museum in Paris and Pont Max Juvenal Aix-en-Provence in France. Blanc, the pioneer of non-modular green systems, covers the walls using metal frame, PVC pipes and felt. In such systems, plants are grown on the felt layer. The wooly pocket system is a system wherein breathable felt pockets can be hung on any vertical surface. They are good for growing vegetable, seasonal plants. In present times, woolly pockets can be created from 100 per cent recycled plastics which are available in the United States.

 

GREEN WALL TIPS

Do wish to install a green wall or vertical garden?

Here are some factors you need to consider:

  • Climate of the location
  • Micro climate of the area where green wall will be installed
  • Size of the proposed green wall
  • Duration of daylight
  • Light intensity
  • Irrigation and drainage facilities
  • Type of plants
  • Types of mounting systems, sustainability and maintenance



Leave a Comment

Name  
Email Address
(will not be published)    
Website
Comment