Green walls are an impressive collaboration between nature and architecture, between practicality and aesthetics. Covering previously dull surfaces with lush vegetation has many benefits. The possibilities of the technology are expanding as more businesses continue to sow and reap the rewards of living architecture.
Types of Green Walls
Most people envision a green wall in their building as a huge construction project bringing with it a huge commitment and price tag. Inscape Green Walls can help you open up your imagination and breathe life and flair into your building with many options including climbing plants, trellises, suspended structures various plantings, fixed green walls or living columns.
There are ever expanding multitude of ways to implement a green wall, to cover all practical and aesthetic needs. Inscape can supply you with easy to maintain, modular green wall systems or a unique and inspiring custom structure.
Soil-less green walls can come in the form of specially developed foam pockets for plants, mosses in various shapes or climbers which have a soil base not supported by the wall itself. Soil-less green walls are lightweight and suited to retrofit projects although foams usually require specialised irrigation systems.
Green Walls with Soil
Green walls which use soil to grow plants have much more health and environmental benefits than their soil-less relatives and are surprisingly much more flexible in maintenance options and even portability.
It is actually the volume of soil which is measured in metrics for assessing the environmental impact of your building. The soil keeps your plants healthier, retains water for much longer (therefore requiring less energy demands for watering) and provides a sink for greenhouse gases and the harmful pollutants in the air within our cities.
A green wall with soil is often surprisingly easier and cleaner to maintain as most systems allow small pot type modules to be taken in and out of the wall without affecting the overall system. This modularity also means plants can be grown offsite before installation of your green wall, therefor eliminating the waiting period between installation and your green wall looking healthy and lush with plant life.
Why is soil so important?
Air quality is a major concern for city dwellers. Smog and pollution leads to asthma and respiratory problems (Timonen and Pekkanen, 1997), especially the presence of nitrogen oxides, carbon monoxides and sulphur monoxides which are emitted from cars and industrial sites. Poor air quality in urban areas has been estimated at killing 800,000 people every year around the world (Kenworthy, 2002).
Soil in a living architecture structure traps particulates and captures toxic gases. It also regulates indoor temperatures and lowers summer highs. This reduces energy usage and the associated pollution from running heating, ventilation and air conditioning systems.
Aside from the thermal mass provided, vital soil functions are the reason why soil gives us so much value and improves our environment. Those functions can be classified as follows:
Soil stores, moderates the release of, and cycles nutrients and other elements. During this, similar to a water cycle, nutrients are transformed into plant absorbable forms, retained, or lost through air or water.
Soil moderates flow and storage of water, including solutes in the water such as nitrogen, phosphorus, pesticides, and other compounds. When healthy, soil partitions water for ground absorption and plant and animal use.
Soil provides a diverse chemical and physical environment to help a variety of plants, animals and organisms thrive together. This environment is automatic and regenerative as opposed to a synthetic growing membrane which needs to be designed for specific growing environments.
Soil functions as a filter for air, water and other resources. Toxic chemicals can be made unavailable to plants and nutrient levels regulated.
Soil provides a medium for plant roots, avoiding erosion while maintaining its porous structure for water retention and circulation. Soil can also support other man-made structures and protect building surfaces.
What is the Urban Heat Island Effect?
Urban areas are often significantly warmer than their surrounding rural areas. This is due to the density of buildings and human activity in built up cities. The difference in temperature is most apparent at night when the vast areas of impermeable concrete and roads radiate the heat they have absorbed during the day from the sun and excess energy from electricity usage (such as running many computers or large air-conditioning systems in office buildings).
This isolated change in conditions affects the ecosystems within and surrounding urban areas. Warm water flows out of the urban areas and polluted air (the production of pollutants is increased by the heat) travels into surrounding areas.
The extra heat present in urban areas also requires buildings to be cooled further therefore resulting in more energy usage and higher energy costs.
Implementing green architecture helps to cool buildings and reduce this effect whilst also helping to mitigate the effect on the air and water quality. Green architecture can include green walls and green roofs, which both regulate water and air temperature and reduce air pollution. The urban heat island effect can also be minimised through using light coloured materials which reflect more of the sun’s energy.
What is Thermal Mass in Buildings?
The term thermal mass describes a part of a building’s structure which alters the way the building deals with excess energy in the form of heat simply through using a material with a lot of mass (it is very heavy due to it being very dense or very thick, such as a large slab of concrete). A structure with more mass takes a lot longer to heat up.
A building with good thermal mass (in the right location) can slowly absorb the large amounts of excess heat from the sun during the day, delaying the time it takes for the heat energy to reach the inside where everyone is working in comfortable conditions. This means heat is radiated from the structure later in the day when the outdoor temperature has cooled. With good thermal mass a building’s inhabitants and air-conditioning system don’t have to deal with a lot of temperature fluctuations throughout the day. Having a living wall inside a building with poor thermal mass along with a green roof garden can have a marked impact on temperature fluctuations.