Lean Cities - Low Carb Materials & the Role of Restorative Sustainability

David Baggs, CEO and Technical Director


The current focus on energy supply sources in relation to the greenhouse impacts of current cities is only the tip of the iceberg in mitigating the societal impacts of climate change and resource utilisation. Just as we count carbohydrates to lose weight, our over-bloated cities and individual lifestyles need to go on a different kind of 'low carb' diet. Instead of counting carbohydrates, we need to count carbon outputs.

While this might smack of a single focus on energy once more, we need to realise that consumption per se is a major factor in itself. Just as we talk about the need for balanced lifestyles, we need to re-double and quadruple our focus on creating and utilising eco-balanced products, materials and technologies. This involves not just energy and resource use but the whole process of how we create and re-create the built environment.

This paper looks at what it will take to make eco-balanced cities and eco-balanced products that are engineered with multiple life-cycles considered before sale and how they can be re-use enabled by information flow into design, construction and higher levels of activity in physical re-sculpting at end of use. The Concept of Restorative Sustainability and the ecospecifier website as a tool is presented and case study solutions provided.

1. Introduction

According to Global Footprint Network, as a global society, our planetary impacts ceased to be able to accommodate sustainably sometime around 1985. At current growth and consumption rates, if all societies choose to develop in the same way as Australia, the US and many other 'developed' nations' we will need up to the equivalent of 2-3 planetary ecosystems to support our needs and demands. 'Developed nations', our Cities, our lifestyles and attitudes are the drivers of the biggest challenge humankind has ever faced and it is entirely of our own doing.

The current attention being placed on global warming and the need to reduce fossil fuel energy consumption is being turned into a political, spin-managed, sound-bite driven issue that except for Nature's constant reminders, whether by storm (Hurricane Katrina - St Orleans 2005, Cyclone Larry - Australia,  2006), Australia's 'worst drought in 1000 years' and  recent flooding in Australia, would become yet another over simplified media message that soon becomes lost in the morass of self interested lobby-group counter message  and mis-information campaigns only to be dropped when the public's attention wanes. As cynical as this sounds, recent history has shown this to be only too true with the secret funding of mis-information campaigns by oil companies and the 'Carbon is Life' mass media advertising in the US launched to attempt to counter the public influence of Al Gore's movie 'An Inconvenient Truth' in late 2006.

While global warming and climate change have become big news now and likely to become bigger with the likes of Rupert Murdoch and News Limited's conversion to active support of mitigating climate change by going 'Carbon Neutral', there is a real need to look beyond the superficial sound bites and the politically driven mantra that climate change is largely due to the obvious energy consumption of electricity and transport.

Digging deeper we see that while the energy consumption of electricity and transport in homes and businesses is obviously a major issue there is significant carbon other resources embodied in the actual buildings, infrastructure and lifestyles as well.

There are also more fundamental drivers underlying this energy consumption that are not being addressed. The 'great unsaid' in the debate to date is consumption in general i.e. the insatiable drive to own more and more, bigger and better, newer and different, the desire of developing nations to emulate our profligacy and more fundamentally, our growth economic models that recognise all economic activity as 'positive' (even if it is rebuilding from natural disasters or cleaning up after toxic spills that have devastating environmental consequences) and still more fundamentally, population growth itself. There is a dire and increasingly pressing need for us to look at the way we measure our success.

"The economy is a wholly owned subsidiary of the environment, not the reverse."
Herman Daly, The ex Chief Economist for the World Bank, Quoted in 'The Age' May 4 2007

As more and more global population drifts into cities to attempt to find shelter, stability, and a more prosperous life, there is also an increasingly strong, commercially driven, acquisitive, 'Home Beautiful-esqe lifestyle' behaviour that is seemingly fed by an upward spiral of media goading.

While it takes massive amounts of energy to run cities, it also takes vast amounts of energy to build cities, acquire the resources to fit them out, move about in them, provide infrastructure, resource, feed, clean, maintain, demolish and renew them. Whether it be in building new or refurbishing homes, commercial or industrial buildings, or our commitment to buying the 'latest and greatest', there is a need for us to change our behaviour about what we design, construct or buy, how we use, maintain and even dispose of all personal and societal 'acquisitions'.

To date, when considering how we might reduce impacts, we have, importantly tended to focus on reducing future impacts by the now common '3Rs' catch phrase of actions, 'Reduce, Re-use, Recycle' and a range of variants promoted by such pertinent books as Lovins et al in 'Factor Four - Doing More with Less', William McDonough and Michael Braungart's 'Cradle-to-Cradle', Paul Hawkins 'Natural Capitalism' and Janine Benyus 'Biomimicry'. Focussing on how we reduce past impacts has to an extent been left in the margins and to nature. It has been assumed that 'if we reduce our impacts, nature can look after herself and will recover in time'. While the 'Reductive Sustainability' most discussed in the above works including initiatives like incorporating past waste into new products or 'doing twice as much with half as  much' (Factor Four), have a critically important role in promoting sustainability up to a point, how can we create a net positive impact to redress the past if we only ever reduce a future negative impact?

Along with all the necessary strategies dealt with in the above works, there is a need for an additional 'enhancing nature' focus. A focus on how we can begin to pro-actively support nature where possible, to create initiatives that have a 'net positive' impact that 'put back' more than they 'take out' of  our 'Natural Capital'. These are initiatives that can be described as 'Restorative Sustainability'.

This paper looks at the role of cities in our un-sustainability and explores the full spectrum of strategies and solutions as to how cities might become a pathway towards a 'Low Carb' future and how, using carbon as a proxy, we can move towards a more sustainable future with cities as part of a '5Rs' solution.

2. The 'Inconvenient Truth'

This paper will firstly analyse the major issues and actions within cities generating impacts that are accelerating our unsustainable demands on our Natural Capital, then look at the  important 'Reductive Sustainability' actions that can be implemented to reduce future impacts. It will then investigate a definition of what makes something 'restorative' then present some examples of 'Restorative Sustainability' initiative and how cities can be used as part of the solution.

2.1 The Issues
When we consider the impacts of cities and the societies that live in them, it is useful to understand where the impacts are being generated and more importantly, where the potential savings are. Most studies, such as the Vatenfall study cited below and illustrated in Figures 1 and 2, when reviewing these impacts, only review recurrent operational impacts:

The buildings sector generates 8.2 GtCO2 or 21% of total global CO2e emission; 8% through emissions from primary fuel types (coal, gas, oil), 13% generated from power production to meet electricity demand from residential and commercial buildings. The residential subsector, while contributing 76% of consumption, contributes 63% of emissions, while the commercial sector, while generating 24% of consumption contributes to 37% of emissions; the difference in emission intensity is driven by different energy mixes. The developed world (EU + US/Canada) generated overall 63% of total anthropogenic CO2 emissions in 2002. Energy consumption by this sector is expected to grow 50% by 2030 with a 70% increase in emissions to 14 GtCO2e driven partly by a fuel shift towards electricity. (Vattenfall 2007).

sector greenhouse emissions.pngend use greenhouse emissions.png

Figure: 1 Global greenhouse emissions by sector         Figure 2: Global greenhouse by End Use 2002 (Vatenfall 2007) 2002 (in Vatenfall 2007)

Furthermore, seen from figure 3 below, the growth in this sector has been astronomical over the last 50 or so years.

materials consumption growth.png

Figure 3: The growth in US materials consumption by sector 1900-1995 (Matos & Wagner, 1998)

A significant amount of energy is 'hidden' and largely ignored within these materials used in the fabric of cities, buildings and their infrastructure. The energy embodied within materials, products and technologies is a key factor in the carbon footprint of cities as a result of their raw materials procurement, manufacturing and packaging, is being overlooked in the macro studies of potential CO2e savings.

Buildings account for one sixth of the world's fresh water withdrawals, one quarter of its wood harvest, and two fifths of its material and energy flows… Building and construction activities worldwide consume three billion tons of raw materials each year or 40 per cent of total global use. (Roodman & Lenssen 1995).

When we look at the relevant proportions of operational vs. embodied energy in the residential sector, as exemplified by the analysis of a typical household in Figure 4, and a 40  year analysis of 40,000m2 office building in Figure 5, the majority of energy is consumed in operational energy. However, we also see a significant proportion of overall energy resulting from embodied energy, not just of the buildings themselves but of also of recurring consumption as part of the overall 'lifestyles' of occupants.

In the residential sector this is seen as a personal or family 'lifestyle' and in the commercial sector the 'lifestyle' and purchasing patterns of companies result in the second highest embodied energy factor being the 'churn' of furniture, fittings and finishes due to short leases, corporate image and fashion design trends.life cycle enery.pngFigure 4: The proportion of energy attributable to initial, recurring, and operational energy of residential households (Treloar et al, 2000).

life cycle delivered energy.pngFigure 5: The proportion of energy attributable to initial, recurring, and operational energy of a 47,000m2 commercial office building over 40 years. (Treloar et al, 1999).

What's more, as can be seen in Figure 6, in recent times we are using less and less renewable sources of materials (which tend to be low embodied energy) in favour of non-renewable materials.

non-renewable materials growth.pngFigure 6: The growth in non-renewable materials 1900-2000 (Wagner, 2002)

The real impacts of Electricity
There is also a need to look below the superficial media headlines and stop sweeping 'inconvenient' and unpalatable truths under the metaphorical carpet.  The focus on global warming due to carbon emissions is actually a little like the proverbial 'canary in the cage'. As seen above, electricity emissions are a major source of CO2, (and can be seen as proxy for the following impacts) but we conveniently ignore its other major environmental and human health impacts. Mercury is a highly toxic, bio-accumulative heavy metal, yet nearly 45% of emissions of mercury (66 tonnes) to the environment in the US alone are from electricity generation (calculated from Wagner 2002, pg.12). Other by-products emitted to air that create significant health impacts include PM 10, PM 5 and PM 2.5 fine asthma and cancer-causing particulates, photochemical smog producing, NOx and SOx, sulphuric acid, chlorine, (Hunwick Consultants 2007), 43% of all mercury, 42% of all cadmium, 38% of all cobalt, 31% of all antimony (Environment Australia 2002) and vast volumes of radioactive ash in Australia.

Heat Islands: The Urban Negative Feedback Loop
A major negative global warming 'feedback loop' has emerged in the way that our cities have now been shown to heat up and retain heat compared to surrounding less densely settled surrounding areas. This 'urban heat island' effect has been identified around the world and most recently in Melbourne Australia. Melbourne has been shown to be on average 3.5-4.5oC hotter during summer evenings and up to 10.0oC hotter on still summer evenings. Obviously with more and more people moving into cities, as it gets hotter, more air conditioning is installed and it will be run more often, creating the 'negative feedback loop' that then generates even more CO2. This effect has become so extreme in Tokyo, that the city has, since 2000 mandated the use of  green roofs on public buildings over 250m2 and private buildings over 1000m2.

heat island profile.png

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Figure 7: Isothermal net graph of Melbourne, Australia's urban heat island effect by University of Melbourne. (Morris 2000)

Above: a diagramic profile of and urban heat island - (Rosenfeld et al, 1997)


In beginning to look at how we can ecobalance our cities much has already been done to analyse what benefits can be found. In Figure 8 below, it can be seen that of the 26.7 gigatonnes of potential annual savings of carbon emissions costing under €40/tonne, nearly 14% are in building alone and the influence of the buildings, materials, infrastructure and consumption can be seen throughout the rest (McKinsey 2007).abatement potential.png

Figure 8: The abatement potential of greenhouse gas emissions for carbon cost under €40/tonne

The recent Vatenfall study showed a total of 3.7 GtCO2e of low-cost abatement options have been identified - 3.0 GtCO2e in the residential sector and 1.3 GtCO2e in the commercial sector - which would hold emissions growth to 26% for the Construction sector by 2030. Heating and ventilation including building envelope improvements, water heating and air conditioning provide the largest potential benefits for both residential and commercial buildings, contributing a total of 2.3 GtCO2e (62%). Lighting is a potential contributor mainly in residential building, potentially leading to a 0.3 GtCO2e emission reduction. Improving other appliances and reducing standby losses yields another 1.1 GtCO2of abatement (Vattenfall 2007).

3.1 The Role of Materials & Design: 'Reductive Sustainability' as Part of the Solution
If we are to reduce CO2 by 60% by 2050 to stop global warming rising beyond 1oC to the 2-2.5oC that current emissions rates would generate (Raupach 2007), further economical savings need to identified. The role of materials has been highlighted in the above data and provides ready evidence that materials have a key role to play. Key issues identified to this point are:

  • Embodied Energy
  • Energy Consumption

The key next question is now - how can cities and their material's potential as part of the solution be realised? There are a number of key strategies where materials selection and the ways in which they are incorporated into buildings can provide benefits with little, or often no cost, sometimes even with cost savings. These focus on reducing impacts by design, cleaner production strategies, materials selection and evaluation strategies. They can all be categorised as falling within the concept described by this author as 'Reductive Sustainability' as the following strategies illustrate:

Materials choice: There is much to be gained from identifying the 'best of class' within any materials categories. As can be seen from the comparative embodied energy data of different residential building assesmblages in Figure 9 above, there can be up to nearly a 1900% difference between the best and worst performers in some categories

co2 material.png

Figure 9: Mean value for global warming potential and the highest and lowest value within the range for residential assemblages (Walker Morison, 2007)

Industrial Ecology & 'Cradle to Cradle': Since the early nineties, various authors including Frosch (1992), Allenby (1992) and Ayres (1994) have introduced the concept of industrial ecology where technical cycles are designed to mimic natural organic cycles in nature, where there is no waste and all. McDonough and Baungart (2002) coined the terms 'Waste equals Food' and 'Cradle to Cradle' to describe how the carbon (and ecological) footprint of materials products and technologies (and cities) need to be re-designed to ensure that the materials inherent in them and their production and manufacture systems will allow all elements or sub-components of any product on deconstruction, to fit within one (or possibly both) of these cyclic production/consumption/remanufacture/consumption systems. To ensure this approach works products need to be designed for disassembly.

Design For Disassembly (DfD): Manufacturers and all sectors of the built environment including designers, engineers, specifiers, builders and developers need to design, manufacturer and incorporate materials, products and technology in cities (and the built environment generally) in ways that facilitate DfD, or at the very least do not hinder it. Only in this way can we be assured that once we have created a resource, that it is not lost and can enter the 'Cradle to Cradle' re-cycling loops and not need to be replaced with virgin resources at end of first or subsequent use.

Design For Climate (DfC): Also known as 'passive solar' design, this term is not used as much recently as a result of the erroneous perception that it does not relate to warmer climates. DfC means designing buildings and incorporating materials in such as way as to maximise the use of environmental heat sinks and sources in the heating and cooling of the internal spaces for thermal comfort and daylighting. The simple orientation and appropriate use of windows, shading, insulation, ventilation and thermal mass is sufficient in many climates to produce buildings that require no heat or cooling and little artificial lighting energy. DfC is the most powerful design strategy we have to minimise the carbon footprint of operational energy consumption in buildings. We are yet to see zero-carbon footprint buildings mandated (although the UK is planning to) although they are technically feasible in most climates.

Buy Recycled: One of the most important initiatives to ensure that the carbon footprint of materials are minimised is the make sure that products being purchased and specified already contain recycled content. While being recyclable is important, first priority should be given to those products that already contain high levels of preferably, post consumer content and have constituent componentry clearly identified to facilitate the next recycling cycle.

Design for Durability: The single most important issue in life-cycle impacts of buildings and materials is durability, providing the carbon payback period is more or less, short term. It is an unfortunate reality than many (not all) highly durable materials are high in embodied energy. For this 'carbon investment' an 'avoided energy' return needs to be calculated, i.e. are the savings that accrue as a result of a material or product's durability due to avoided maintenance or unnecessary replacement, create more carbon savings than the initial investment, over a term of preferably less than 10-40 years (given the 60% reduction target by 2050 to contain global warming to rising beyond 1 degree or less). The key action here is for designers to;

Start by designing with the end of life in mind. If it's not reusable or recyclable to a high value, it's not sustainable. This design approach drives design re-thinking throughout the project, requiring the design team to think 'up' from the construction of building elements to the whole building. (Walker Morison, 2007)

Biomimicry: By using nature as a model we are finding amazing ways to reduce the impacts of how products are made and recycled. Janine Benyus in her 1997 book looks at case studies of how products are being designed using natural criteria and processes.

Nature as Model. Biomimcry is a new science that studies nature's models and then imitates or takes inspiration from these designs and processes to solve human problems, e.g. a solar cell inspired by a leaf.

Nature as Measure. Biomimicry uses an ecological standard to judge the "rightness" of our innovations.  After 3.8 billion years of evolution, nature has learned: What works.  What is appropriate.  What lasts e.g. high durability plastics made like abalone lucre at room temperature.

Nature as Mentor. Biomimicry is a new way of viewing and valuing nature.  It introduces an era based not on what we can extract from the natural world, but on what we can learn from it.e.g. natural reedbed waste treatment systems instead of chemical dosed electro-mechanical systems.

Key lessons that can be drawn from this approach relate to how products are evaluated, how to choose between alternatives and how we integrate industrial ecology cycles, ensuring that the materials and technology with the lowest carbon and toxic life-cycles and biodiversity impacts prevail. Working with nature to restore function is implicit in the concepts promoted by biomimicry, however, there is no explicit focus on restorative solutions.

Dematerialisation & Factor Four+: Dematerialisation is about  increasing the efficiency of materials e.g. the Weisacker and Lovins' Factor Four: Doubling wealth, Halving Resource Use' is about 'doing twice as much with half as  much'. It is essentially an economic concept wherein technologies and processes are developed to use a lower amount of resources to meet the human need for goods and services (increased resource efficiency sometimes also known as eco-efficiency), it enables technology and the economy to act as efficient driving forces (market mechanisms, financial incentives). Dematerialisation is also an issue in building design where efficient use of resources can be influenced by structural design efficiencies, detailing practices and the level of finish. As an extension of this concept, The Factor Ten Institute believes that for planetary sustainability, developed nations should be targeting Factor Ten efficiencies in dematerialisation (Schmidt-Bleek).

Renewable Inputs: Subject to where and how products are manufactured, transported and used and hence the extent of the importance of durability, the use of renewably sourced products can have a major impact on reducing overall environmental and carbon impacts. Some renewable materials are highly durable, e.g. Western Red Cedar. Renewable materials can still be sourced in ecologically unsustainable ways, so care must be exercised that resources are sourced sustainably e.g., by recognised 3rd party sustainability assessment systems such as the Forest Stewardship Council sustainable timber certification scheme or other third party evaluation process.

Identify Carbon Sinks: Some products that bind large amounts of carbon in the materials themselves during use are called carbon 'sinks'. Provided the materials are long lived, there are significant benefits in starting to increase the use of products that are high density carbon sinks. As shown in figure 10, even among the renewable materials field there are claims of preferential carbon sink benefits beginning to emerge. How these products are dealt with at end-of-life then becomes doubly important if the embodied carbon is not to be released into the atmosphere.

co2 sequestration.png
Figure 10: Showing the claimed carbon sink benefits of a natural rubber based flooring over other natural and synthetic floor coverings (source: Dalsouple International)

Embodied Water: Another emerging issue due to both lack of the resource as a result of  global warming and the negative global warming impacts of the embodied energy of water is the embodied water content of products. The impacts of water consumption in both manufacture and maintenance will become increasingly important as the focus on water availability increases. Crawford and Treloar (2005) showed that the embodied energy content of a 11,200m2 office building ranges from 6.3 kL/m2 using process analysis, to 54.1 kL/m2 using Input-Output-based hybrid analysis (that includes National Account data including financial and infrastructure system inputs). As occurs using the same comparison process for embodied energy, this difference in values can be attributed to the truncation typically associated with process analysis.

3.2 Materials & Design: 'Restorative Sustainability' completing the solution
As discussed in the Introduction, the 'Reductive Sustainability' initiatives discussed above have a critically important role in promoting sustainability up to a point. If we reduce our demands on nature's systems and living resources, there is no doubt that regeneration will occur to some extent.

The key question is 'can nature replenish herself in the context of explosive consumption, ongoing population growth and the inexorable growth of cities where impacts are concentrated and populations insulated from their impacts?'  The current collapse in the integrity of ecosystems globally is indicative that this is highly unlikely. The plain likelihood remains that we will be unable to create enough relaxation in the societal demands we place on natural capital to allow adequate natural recovery in currently highly stressed, damaged or destroyed ecosystems to ensure sustainability in the long term if we only ever reduce future negative impacts without redressing past impacts.

Along with all the necessary strategies dealt with above, there is a dire need for an additional 'enhancing nature' focus. This focus on pro-actively supporting nature requires us to where possible, create initiatives that have a 'net positive' impact that 'put back' more than they 'take out' of  our natural capital. If we are to restore natural capital pro-actively, then as part of every possible project we need to integrate initiatives that 'Repair and Restore', such initiatives are described by this author as 'Restorative Sustainability'. However, before we can define what constitutes 'net positive' repairing and 'restorative' solutions, we firstly need to identify what actually constitutes sustainability from a scientific viewpoint.

3.3 Defining Sustainability
While there are numerous literary definitions of sustainability per se, such as the Brundtland Commission's and Australia's National ESD Policy, that focus on mitigating impacts, maintaining intergenerational equity and working with the 'Precautionary Principle', these are very broad overarching principles that do not really help us actually identify and  implement actual strategies. In fact, we do not really have a clear idea what a truly sustainable city actually looks like or how it can operate given the extent of existing development infrastructure and systems. There is no doubt that a truly sustainable city will of necessity be radically different to what we are doing now - not just from a physical standpoint, but from a systems (transport, services, energy etc) and societal standpoint as well. According to the Australian CSIRO, the 3 'Sustainability Wedge' strategies required to deliver sustainability are, as seen in Figure 11:

  1. A values based decline in consumerism
  2. A dematerialisation of product and services; and
  3. Closing the loop in industrial ecology.

CSIRO unsustainability.png

CSIRO sustainability.png

Figure 11: CSIRO vision of unsustainability and its impacts (top) and 3 proposed interventions necessary to deliver sustainability.

These strategies provide some general guidance on the directions we need to move to redress unsustainability. However the Natural Step Institute has developed 4 System Conditions for Sustainability that define sustainability from a scientific standpoint:

  1. Substances from the lithosphere (within the earth) must not systematically increase in the ecosphere;
  2. Substances produced by society must not systematically increase in the ecosphere;
  3. The physical basis for the productivity and diversity of nature must not be systematically deteriorated;
  4. Fair and efficient use of resources with respect to meeting human needs.

These system conditions need to form the underpin to our assessment of products, services and strategies on the broadest scale possible.

3.4 Defining 'Restorative Sustainability'

If we are to solve the looming global warming crisis, we need all the tools in our armoury to be fully primed and must be ready to actively implement them.

sustainability wedges.png


Figure 12: The full complement of 'Sustainability Wedge' Initiatives required to deliver sustainable, lean, ecobalanced cities (adapted from Heij 2002)

In addition to the 3 sustainability wedges adapted by Heij (2002) from Raskin (2002) a fourth needs to be added;

  1. A values based decline in consumerism;
  2. A dematerialisation of product and services;
  3. Closing the loop in industrial ecology; and
  4. Identifying and incorporating 'Restorative Sustainability';

Figure 12 above shows the 4 sustainability wedges that are actually needed for cities to begin the major process of holistically moving toward real sustainability, towards the goal of being lean and eco-balanced.

So what is 'Restorative Sustainability' and what constitutes a restorative solution? To be restorative a strategy, process or product would meet all TNS System Conditions for Sustainability plus involve one or more of the following ;

  • Reduce past concentrations substances from within the earth;
  • Reduce past concentrations substances produced by society in the ecosphere;
  • Repair and restore ecosystems and increase the diversity of nature;
  • be long lived perpetual or self perpetuating;
  • be non maintenance or low maintenance;
  • likely to be biological or biomimicking.

So far as outcomes are concerned, they create:

  • net positive environmental and health outcomes;
  • multiple ecological benefits;
  • long lasting effects.

3.5 'Restorative Sustainability' Solutions in Practice

A range of initiatives that have been identified as currently available and meeting the above criteria are presented below. There may well be others not yet identified and this author would welcome suggestions as to others or comments on the above proposed criteria.

Climate Positive: An Australian carbon offset organisation that focuses on tree-planting offsets that are equivalent to 1.3 times the actual carbon footprint of the offsets as calculated by their online calculator. For every tonne of CO2 subscribers produce, 1.3 tonnes is offset - 1 tonne with verified emission reduction projects, and an additional 0.3 tonne over time through ecologically diverse forest restoration projects. All or part of an individual, family or company's annual CO2 emissions including travel, food, buildings and lifestyle can be offset. Biodiverse forests are grown in the Strzelecki Ranges where some of world's most carbon-rich forests once stood. (ClimatePositive)

Green Roofs and Earth Integrated Buildings: Green roofs, earth integrated and earth covered buildings provide a diverse set of benefits including potential:

  • energy savings - provided insulation, soil cover, and vegetation are properly considered;
  • air pollution and CO2 sink - absorbing and binding airborne pollutants including CO2 into biological matter resulting from the interaction between soil, micro (micro-organisms) and macro fauna and flora;
  • nutrient & pollutant sink -  cleansing water and minimising downstream pollution;
  • stormwater volume reduction;
  • biodiversity restoration - based on soil cover, and vegetation properly considered for locally indigenous plants etc.;
  • reduced urban heat island impacts;
  • higher levels of visual amenity;
  • Lower maintenance and longer life of roof surfaces;
  • Dual land use including recreation and productive urban garden potential (Baggs et al 2007).

As a word of caution, it is important to consider the whole-of-life-cycle greenhouse impacts of green roofs and earth covered building. The deeper soil profiles associated with better energy returns tend to require more structural resources and hence higher greenhouse intensity (due to higher embodied energy). So analysis should be undertaken to ensure that greenhouse benefits return a less than 10-30 year carbon payback, i.e. the operational energy savings and environmental benefits of the development need to offset the whole embodied energy of the construction within this period (as well as having a neutral ecological footprint) to avoid exacerbating global warming.

Green Walls: The benefits of plantscaped walls depends to some extent whether the soil in which the plants are growing is in contact with the building's walls or not. If so, higher thermal benefits will result (with likely increased embodied energy as in green roofs above).

Plantscaping in general provides numerous benefits similar to green roofs, but to a slightly lesser extend depending on the volume of soil present:

  • energy savings - providing shade and insulation effects;
  • glare control - depending on design and prominence;
  • air pollution and CO2 sink - absorbing and binding airborne pollutants including CO2 into biological matter resulting from the interaction between soil, micro and macro fauna and flora;
  • nutrient sink -  cleansing water and minimising downstream pollution;
  • biodiversity restoration - based on soil cover, and vegetation properly considered for locally indigenous plants etc.;
  • reduced urban heat island impacts;
  • higher levels of visual amenity;
  • Lower maintenance and longer life of roof surfaces;
  • Dual use including privacy (e.g. CH2 Building, Melbourne City Council)  and productive urban garden potential.

Plantscaped Interiors: Have been shown by research to reduce air pollution and provide CO2 absorption. They absorb and bind indoor volatile organic compounds (VOCs) and airborne pollutants including CO2 into biological matter. This ability results from the interaction between soil and micro organisms. Plants also provide additional psychological benefits resulting in a contribution to increased worker satisfaction and potentially productivity.

For EARTH Probiotic Water Treatments: Are non-toxic, biodegradable, and self perpetuating, probiotic treatments which digest solid waste, transforming effluent ponds into usable water. They are suitable for any organic waste removal and organic odour control and sanitation in industrial, commercial and residential applications. For EARTH products assist in the treatment of waste and wastewater by eliminating organic odours and accelerating the breakdown of solids. They contain beneficial bacteria to effectively reduce Biological Oxygen Demand (BOD), ammonia, nitrates, nitrites and other pollutants including TSS (Total Suspended Solids) E-Coli and pathogens including faecal coliforms in effluent ponds and sewage systems. The product is suitable for organic waste removal applications such as piggeries, and septic systems. The use of these probiotics in waste-water treatment plants has the effect of multiplying the efficiency of the plants significantly - up to several times. This could potentially save some large scale industrial or municipal waste water treatment plants tens or even hundreds of millions of dollars in avoided upgrade requirements or at the very least significantly delay the expenditure. The microorganisms continue to assist even out into the broader environment maintaining their beneficial conversion of nutrients and reduction of pathogens provided aerobic conditions exist.

Desert Cube Waterless Urinal Conversion: Desert Cube Waterless Urinal System also contains naturally occurring microbes to turn existing trough or bowl facilities into touch-free waterless urinals. The embedded microorganisms naturally breakdown the organic matter inside the drain and interfere with the bacterial digestion that produces unpleasant odours. They also reduce the ability of faecal bacteria to latch onto urine solids as a source of food. Reduces drain clogs and stains by converting uric scale deposits into more soluble compounds and reduces pathogens. Cubes are placed in the base of the urinal and the water supply is turned off. Beneficial microbes are released as the cubes slowly dissolve over several weeks. Cubes are 100% biodegradable and safe for septic and sewerage. An all purpose Washroom Cleaner is also available with scale inhibitor and naturally occurring microbial strains to reduce washroom odours.  Reduces water use by up to 98% as only a single daily cleaner flush is required. Reduces use of chemicals and is suitable for use during development or in existing buildings any type of urinal, as the system is installed after construction. As above, the microorganisms continue down the pipe to assist in the sewage treatment plant and even out into the broader environment to continue their beneficial conversion of nutrients and reduction of pathogens provided aerobic conditions exist.

Net Positive Renewable Energy: Renewable Energy sources are greenhouse emission free except for their embodied energy. Different types of systems have differing rates of embodied energy payback:

Crystalline Silicon Systems: e.g. BP Solar, Origin Energy
Energy Payback period - 4 years.

Thin-film Photovoltaic Systems
Amorphos Silicon Systems: Energy Payback period of thin-film technologies is similar approx. 2-3 years (with frame).
Cadmium Telluride (CaTe) Polycrystalline Systems. Energy Payback period - 0.9 year (1.9 yrs with frame)
Dye Solar Cell (DSC, 3rd Generation PV Systems). Energy Payback period - 0.31 years. (Baggs & Haines 2006)

While the size of a PV or other renewable energy system is designed to replace only the emissions of a particular load, it is a 'reductive sustainability' solution. However, as soon as the embodied energy is paid back and the energy generated exceeds the annual load of the site providing net positive energy into the grid it can be said to be a 'restorative solution'.

Peak metal: A word of warning relating to the rarity of some metals being incorporated into photovoltaic systems - some of the rarest metals on the planet are being incorporated into PVs, e.g. indium (gallium indium arsenide amorphous), telluride (CaTe PV) and ruthenium (DSC PV). Some of these metals are so rare some researchers are already discussing peak metal availability approaching within a few years with the cost of indium rising nearly 17 times between 2003-2006 ($60/kg-$1000/kg) and only five years of known resources left (Cohen, 2007).

Restitution of Indigenous Plant Associations and Ecological Values: While not relevant to every site, some sites and roofs tops may be suitable for the re-establishing of areas of plantings using locally indigenous plants and soil profiles. While this not an inherently easy process, if enough patches of restored ecosystem started to be installed, it is likely to provide additional biodiversity benefits by allowing and encouraging the repopulation of areas with indigenous native insects, birds and other animals. When grown on roofs, the benefits of green roofs (see above) would also apply.

Offsite Tree Planting: This strategy is being used widely as an emissions offset tool already. The benefits that accrue will actually depend on a variety of issues such as the area being planted, the planting style (monoculture or diverse), adjoining ecosystem integrity (better if diverse communities planted adjoining high quality forest with similar locally derive seed stock to allow more holistic re-colonisation of the ecosystem over time) and forestry practices (use of baits, genetically modified seed stock or not etc). Systems such as ClimatePositive mentioned above use at least partial diverse plantings in relative proximity to intact ecosystems.

Landfill Mining: The extraction of landfill gas could be seen to be a restorative process in as much as it, in effect, reduces past impacts.

Tools for Implementation: One of the factors limiting the implementation of sustainability is the difficulty design and construction professionals find in locating products with bona fide preferential environmental and health features.

Ecospecifier.org is an online knowledgebase and database of over 3200 ecologically and health preferred products, materials and technologies which provides verified information to built environment professionals and homeowners alike delivered at the level of detail needed by each market.

The information provided is both quantitative and qualitative, life-cycle assessment based and focuses on all aspects of restorative sustainability including closed loop product cycles. Products have to meet specific entry criteria and all claims are verified by experienced professionals with enhanced listings product manufacturers required to submit third party test data to back all key environmental and health claims. Ecospecifier also reviews products against major international Green Building Rating tools such as Green Star. It is likely also in the near future to be integrating LEED and Green Globe systems into product verification and search processes.


4. Conclusions

Policymakers, designers, engineers and constructors responsible for urban outcomes need to refocus their policy, design and built outcome towards eco-balanced, lean,  low carb cities materials and strategies. The past 'Reductive Sustainability' mantra of the '3Rs' ('Reduce, Re-use, Recycle) needs to be expanded  to include concepts of industrial ecology and  'Restorative Sustainability' and replaced by the '5Rs' 'Reduce, Re-use, Recycle, Repair + Restore'.


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