GS Applications at Urban/Regional Scales
Urban farming: GS can support urban farming, a significant movement to increase urban food security and health while reducing truck transport to and from cities.
Demand for more varieties of food is increasing in urban areas, which can best be accommodated by specialist food production in vertical urban farms. Urban farming can reduce truck transport between farms and cities, and within cities as well. Vertical farming captures economies of scale and takes up less land area. In some cases, urban farming structures are greenhouse structures that use rotating trays to facilitate watering and harvesting and to control the amount of light they receive from skylights.2’ In other cases, abandoned urban warehouses have been repurposed with internal scaffolding structures that support vertical vegetable and/ or flower production.
Rural farming: GS in rural areas can convert land used for monocultural food production hack into biodiversity habitats and buffers to (partially) protect natural areas.
Significant amounts of rural land are currently used for grain and meat production, which can be damaging to nearby ecosystems, waterways, land productivity and even soil biology. Land currently used for meat production could be gradually reclaimed for vegetable and legume production using rural GS structures. Such vertical structures could also free up land for biodiversity habitats and wilderness restoration. Their cost could be offset by savings from substituting more costly processes. For example, they could reduce the use of enormous agricultural machines that dwarf the embodied energy in the solar- or wind-powered equipment needed to construct/operatc the vertical farming.
Desert cities: GS for food production in desert cities could ameliorate the housing problem in a relatively benign way while also respecting fragile desert ecosystems.
A third of the planet’s land area is now desert,24 and many bioregions are being destroyed. Some argue that the physical footprint of solar-powered desert cities would do relatively less harm. Although many species have adapted to deserts, they have fewer ecosystems and species. Water is an issue in deserts, but passive technologies can now capture mists or evaporation of ocean breezes sufficient to support large GS greenhouses.25 The water harvested from the air is pumped through roofs to cool the buildings during the day and water the plants. These structures can be elevated to reduce damage to desert ecologies.
Other regional applications: GS can provide demountable and/or adaptable means of increasing/protecting urban biodiversity and creating a hedge against invasive species, while serving diverse local functions.
There are schools and small communities in rural areas on flood plains or hurricane alleys, or near woodlands that are especially prone to bushfires. GS ‘functionalfences’ with water storage and sprinkling systems located between fire-prone areas and settlements could hinder the spread of fire while providing local benefits.26 Horizontal or vertical gardens in GS structures above or around schools could support outdoor classrooms, social areas, and/or places for children to grow and prepare food while learning about health and nutrition. These structures could serve as backup refuges and relief facilities for communities in case of a natural disaster.
Green Scaffolding (GS) and Eco-Services
The following suggests how GS systems can provide specific benefits for humans and nature in ways that also directly or indirectly support biodiversity.
It should be emphasized that the following examples of GS concern design ‘concepts’, not specific systems or technologies. Since every site and context is different, every application or design of GS might differ in structure, shape and appearance. Design thinking is required to apply them to site-specific environments and constraints. By definition, sustainable design must be responsive to climatic, cultural and biophysical circumstances, while meeting many functional parameters and unique priorities. It would be easy to conjure up situations in which an abstract design concept might not work, but it would be equally easy to resolve these problems by design.
Eco-Services that Support Energy, Materials and Transport
Electricity/fuel production-. Distributed energy systems are not considered as efficient as large-scale facilities such as regional solar thermal plants.2' However, they provide for energy security when electricity distribution networks fail or in a crisis. GS combined with signage and billboards could support solar cells which can provide electricity to adjacent buildings. ‘Algaetecture’ (where transparent tubes of algae are supported by and integrated with facades) can produce biofuels/biogas.28 Algae tubes have doubled as shading devices and other architectural features. A form of GS was proposed for producing biofuels using fast-growing algae in the empty spaces above existing filling stations for feeding non-electric vehicles.
Integrated wind power: Regional or peri-urban wind power systems can be combined with GS functions for additional productive purposes. Some micro-wind generators work on the sides or roof edges of buildings. The use of building-integrated wind generators is problematic due to variable wind velocities, turbulence and intermittence. However, the cavity created by the GS can stabilize the air flow and reduce wind turbulence. The air flow becomes uniform as it moves through the cavity (regardless of wind direction). Therefore, the area between GS exterior panels could harvest wind energy.29 Potentially, then, GS could be combined with small-scale wind turbines for building energy autonomy.
Materials substitution: Although all buildings need occasional upgrades, longevity generally reduces the rate of environmental degradation and resource depletion caused by extracting materials for new construction. GS can increase the longevity of buildings in several ways. They can enable buildings to meet changing circumstances, as in the case of renovating the interior of historic buildings (above). They can prolong the life of older buildings that arc vulnerable to earthquakes or gradual earth movement, by providing (multifunctional) structural reinforcement. When used as walls, GS could
Design for Nature Exemplified 143 reduce the materials used in building facades to achieve better structural/environmental outcomes, and could enable major future modifications.
Land reclamation: Freestanding GS can make use of land that is degraded and being remediated. Since GS is generally on piers/posts and can be energy and water autonomous, it can be installed over brownfield sites (land contaminated by past industrial uses), and/or integrated with urban forests, while the soil is gradually rehabilitated for human use. While decontaminating land, urban forests can also provide timber or bamboo (where appropriate) for construction materials. During the years that bioremediation processes and urban forests are remediating the damaged land, elevated GS walkways, greenhouses and public venues in the landscape will ensure the land is well used.
Transport reduction: Regional transport impacts include human fatalities and road kill, isolation of species into ‘islands’, the climatic and biodiversity impacts of excavating construction materials, and the spread of seeds by vehicle tires. Urban transport impacts include pollution, congestion and the heat island effect from roads and parking garages. Transport to and from the country can be reduced not only by urban agriculture, but by vertical urban composters combined with other functions, such as GS structures that support solar cells. Rural freeways/railways could have Green Scaffolding roofs that support linear algae biofuel production systems along with biodiversity bridges and other locally appropriate functions.