Vauban, Germany, demonstrates carbon reduction

19 February 2014 — In Part 1 of this short series, Dr Vanessa Rauland discussed opportunities to decarbonise cities at the precinct scale. Part 2,  looks at how carbon reduction in urban development can be acknowledged and potentially certified to promote the achievements of progressive developers and help to reduce “greenwash”. With an increase in usage of the term “carbon neutral”, particular attention is given to what this might mean for urban development.

Carbon claims

A variety of new carbon terms have emerged in recent years to help describe the increasingly ambitious environmental and carbon goals being sought, and to differentiate achievements. Some of these new terms include: Carbon Zero (or Zero Carbon), Zero Emission, Carbon-Free, Low Carbon, Carbon Negative, Carbon Positive, Carbon Neutral, Climate Positive and Climate Neutral. However, these terms are rarely well defined and the methodology for calculating emissions, or the process by which a stated carbon goal has been achieved, often remains unclear, leading to a variety of (often unsubstantiated) claims.

The lack of consistency in information around these terms has led not only to confusion, but also to scepticism and mistrust in claims, as few certification schemes are available to verify them, particularly within the built environment. As such, the notion of “greenwash” has increased, leading to a crackdown by the Australian Competition and Consumer Commission.

This research has thus sought to better define what “low carbon” and “carbon neutral” can mean in the context of the built environment and urban development – in all of its characteristics – and develop new frameworks, tools and ways to recognise it.

Carbon neutrality and the built environment

Despite the widespread use and prevalence of the term carbon neutrality within the public domain, there remains no specific, universally recognised definition, nor any widely accepted international certification system. Nevertheless, the general process involves three main steps, which ideally should be conducted on an annual basis. These include: measuring, reducing and offsetting emissions.

In relation to the built environment, this would involve first calculating the carbon footprint of a development, then reducing emissions as much as possible through means such as energy efficiency measures, better building design, transport infrastructure, behaviour change or switching to renewable sources of energy, before finally offsetting the remaining, unavoidable emissions (for example, emissions embodied in materials of buildings and infrastructure).

The first challenge, therefore, is how to calculate the carbon footprint.

Issues for consideration

A range of issues needs to be considered when determining the carbon footprint of an urban development. Some of these include the types of gases, the measurement units, accounting methodology, boundaries, scopes, timeframe, types of emission reductions and allowable carbon offsets.

Particularly in terms of offsets, specific information is required around whether they are produced onsite (from renewable energy generation) or purchased from a third party, and in the latter case, how credible the offset provider is. Some certification schemes, such as the Australian Government’s NCOS Carbon Neutral Program, do not allow onsite renewable energy generation to be used as an offset for other development-based emissions (such as for embodied emissions in materials).




Which gases are included? For example, only carbon dioxide (CO2) or multiple greenhouse gases (CO2-e)?


What unit is the carbon footprint measured in? Is it in weight (eg tonnes) or area (eg global hectares)? 


Is an inventory approach or a Life Cycle Analysis (LCA) used? If LCA is chosen, which methodology, i.e. Process Analysis (PA), Environmental Input-Output (IEO) Analysis, Hybrid EIO-LCA? 


What are the overall system boundaries? Does it include only operational emissions or are supply chain emissions, such as the embodied emissions in materials included?


Which Scopes of emissions are included? Direct and indirect? Scope 1, 2 and 3? 


If LCA is used, what is the lifetime given to the embodied emissions in buildings and infrastructure?


Are there targets set for emissions reduction? What are the allowable emissions reduction options?


Are offsets included? If so, is there a limit? What offsets are eligible? Are they certified, credible offsets? 

The degree to which carbon footprints and inventories vary depending on the inputs and decisions made in relation to the issues outlined above can be substantial (an analysis of these key issues, specifically in the context of the built environment and urban precinct development, is provided in Rauland (2013)). These issues need to be clearly articulated within the definition or the process describing how a carbon footprint has been undertaken and how the stated carbon goal has been achieved.

Defining the urban scale

One of the more difficult tasks associated with calculating a carbon footprint relates to boundaries. Determining the extent of the precinct or “urban scale” in terms of emission boundaries is a challenging process as boundaries can extend almost indefinitely. Moreover, the intricate and continually changing nature of cities, urban areas, precincts and the systems sustaining them, as well as the activities going on within them, make carbon calculations extremely complex. Nevertheless, several attempts have been made and proposals put forward by academia, industry, cities and local communities to define these boundaries, in order to better understand the greenhouse gas contribution of urban development at the various levels.

Most of the current city GHG accounting frameworks focus on production-based, operational emissions, which include emissions arising from business and industry activities occurring within a city’s geographic and legislative boundaries. Much of the recent academic discourse suggests, however, that this focus is misplaced as it fails to recognise and address the emissions associated with a city’s overall consumption of resources and subsequent emissions (such as imported goods, electricity production or waste disposal that occur outside a city’s boundaries), thereby creating misleading per capita carbon footprints of cities.

Directing greater attention towards the precinct-scale for carbon management can help to bridge the gap as it allows more demand-side emissions to be considered, for example, those arising from household transport patterns, energy and water consumption, as well as embodied emissions such as those in construction materials.

Masdar City UAE

Comparing carbon claims from existing developments

Countless developments around the world have already demonstrated the potential to reduce carbon at the precinct level. Some of the more well-known eco-cities, districts and low carbon communities, which have implemented many of the carbon reduction opportunities mentioned in Part 1, include BedZED in the UK, Vauban in Germany, Hammarby Sjöstad in Sweden, Western Harbour in Malmo, Sweden, and Masdar City, in the United Arab Emirates. An analysis of these is provided in Rauland (2013).

While some of the case studies examined have a broader focus on sustainability, others have more carbon specific aspirations and targets. For those focused on carbon, significant variations exist around the approach taken to measure emissions, such as whether they adopt an operational perspective or a life cycle approach, significantly affecting the amount of emissions attributed to their development.

While most developments appear to concentrate predominantly on the carbon emissions associated with onsite energy production and use, many also take into consideration additional factors such as water and waste, though they are not always represented in terms of carbon. The embodied emissions associated with the materials used in the developments examined were rarely accounted for in the carbon analyses, despite this being a growing area of emissions (as our buildings become more operationally efficient).

Transport appears to play a significant role in lowering the per capita carbon footprint of residents living within the case studies analysed, particularly when compared to the citywide average. However, again this is not consistently documented in all developments, nor is it clear how emissions have been calculated.

So are comparisons between developments actually possible?

Without a universal framework or guidelines in place to specify what emissions need be included in a carbon analysis of urban development or what constitutes “low carbon” or “carbon neutral” in this context, comparing developments or claims becomes an incredibly difficult task, if not an impossible one.

Adding further controversy and complexity to claims is the lack of follow up or the on-going evaluation of developments and initiatives, as claims quickly become out-dated, and in some cases (such as where things malfunction), inaccurate.

Precinct or neighbourhood scale is important to sustainability

Tools to calculate the footprint

While the precinct or neighbourhood scale has long been recognised for its importance in achieving sustainability outcomes, it is only in recent years that assessment tools have begun to specifically target this level. Prior to this, assessment tools for the built environment predominantly focussed on individual buildings, evidenced by the copious number of tools now proliferating in this space. The amount of precinct-scale rating tools and schemes, however, is now also growing rapidly (see for example the 2010 report from the Australian Institute of Landscape Architects).

Both energy efficiency and GHG emissions have been a popular focus of the tools over the years, although few in reality have been able to adequately quantify emissions. The new precinct assessment tools can measure various aspects of sustainability well, though most are limited to some form of checklist. None so far have focused solely on GHG emissions or offer a comprehensive or specific enough carbon accounting framework to recognise carbon neutrality at this wider level (see Beattie et al 2012).

The tools offer different typologies of assessment including life cycle assessment, checklists, rating systems, assessment frameworks, labelling and certification schemes. Designed for different end-users and for different purposes, the outputs and functions of these tools vary considerably. The outputs generated from the assessment processes in rating schemes, for example, often use diverse criteria, both qualitative and quantitative in nature, commonly comprising checklists and multi-criteria analyses. They therefore often need to be embedded into point-based frameworks to provide a common metric to calculate the overall rating.

Layers of measurement are also often used, such as themes, criterion and indicators. It is common that a series of indicators will be used to measure specific criteria (or credits), which when combined, make up a broad theme. Weightings, which involve assigning different values to different criteria in order to reflect their perceived importance, are also commonly used within tools. However, as tools rarely provide justification for their allocation of points, weighting is often identified as a relatively controversial aspect of sustainability assessment since it is generally highly subjective.

Decision-making versus assessment and rating tools

A major limitation or shortcoming of assessment rating tools is that they are often adopted too late in the design process, meaning the decisions that can potentially maximise the overall environmental sustainability (or in this case, carbon reduction) are not built in from the start. Developed as appraisal tools, they generally rate developments at the end of the building phase based on seemingly arbitrary checklists, meaning that many of the opportunities to improve performance are often lost long before this point.

Furthermore, it also means that sustainability measures are often “bolted on” at the end of the design process as developers seek to gain credits from tick-box items, which can ultimately end in perverse outcomes.

At the other end of the spectrum, assessment and rating tools that have the ability to weigh up various options based on real numbers and quantifiable benefits, can help to inform the decision-making or pre-design process. Generally identified as “design” tools, they can assist planners, architects and urban designers choose the best options at the beginning of the process, to meet their prescribed goals. Nevertheless, these types of tools, or the this type of function, is currently something largely lacking within the existing rating and assessment tools targeting the built environment, particularly at the precinct level.

From the tools analysed, eTool and PRECINX are the only two tools able to provide this sort of “options-modelling” or decision-support, and are thus considered design tools. However, they currently don’t assess all the areas identified in Part 1 of this series.

Despite the unique value and usefulness each type of tool provides, the lack of coordination and integration between them appears to only be adding to confusion within the industry and to carbon claims.

A new carbon framework for urban development

This research has proposed a new framework for calculating the emissions associated with precinct-scale urban development. It incorporates six main sources of emissions, which it is argued should be included in any carbon analysis of the built environment, regardless of the carbon claim. It could therefore be embedded in all carbon-related rating tools. The emissions include those associated with the site preparation and construction process, embodied carbon in materials, energy production and management, water management, waste management and transport.

Some of the areas identified above have often been neglected by developers in the past, as they commonly fall outside the operational control, and therefore responsibility, of a developer (for example, energy and transport infrastructure). However, they have been chosen and included in the analysis for the reason that they can be influenced by the developer, and because they are of significant interest to the planning agencies.

Indeed, some areas, such as new small-scale technologies and processes for supplying and managing resources such as energy, water and waste at the precinct level, are also increasingly identified as key priorities for developers and are beginning to be targeted in the design of developments. Developers are also starting to realise not only the carbon reduction potential from compact, transit-oriented development, but also the financial value in locating urban development around public transport systems.

Using a hybrid life-cycle/inventory approach when calculating the six sources emissions (both the embodied emissions and ongoing operational emissions) can help to ensure that developers make well-informed decisions around design, materials, location, density and land-use mix. This can help to foster carbon reduction through improved urban planning and precinct design.

If new (and existing) assessment tools could include all of the characteristics, they could become important design tools for achieving planning approval as well for determining the eligibility of a range of other incentives. Providing follow up and evaluation as part of a tool would also prevent valuable information and knowledge from being lost. This would enable developers to learn from each other’s experiences (especially mistakes), thereby providing specialised guidance for future low carbon and carbon neutral development.


Focusing on this level will also help to promote better interaction between key urban stakeholders such as developers, builders, architects, urban planners, utilities, local governments and the community, thereby helping to create tangible change at the ground level using a bottom-up approach to carbon reduction. However, given that there is currently no established governance framework that can help to facilitate a process involving such a myriad stakeholders at this level, a major challenge will be finding news ways to deal with precincts as they attempt to decarbonise. A robust governance structure is clearly needed.

While cities and local governments already have institutional frameworks in place to be able, at a democratic level, to sign on to and implement various initiatives, getting buy-in and collaboration from developers and other key stakeholders who are not subject to, and bound by, the same institutional requirements, is far more difficult. It is argued, therefore, that a framework and process for calculating and addressing emissions at the precinct scale would benefit from linking into frameworks, schemes and initiatives already established at the local government level. This may further benefit local governments by allowing them to develop a greater understanding of their community’s emissions, as well as to discuss future policies and initiatives to address them.

Benefits of a standardised framework

From the issues highlighted, the benefits of creating a standardised framework and approach for quantifying the carbon emissions arising from precinct-scale development are clear. It will not only help to make assertions more meaningful and comparable, but will also make benchmarks possible. This is critical to be able to determine the overall contribution urban development can have in addressing climate change and where reductions can be best achieved. It could also allow urban development to be able to gain carbon credits through the Coalition’s new Direct Action Plan.

Dr Vanessa Rauland

It is expected that the creation of a new mechanism to certify and acknowledge the carbon reductions achieved within urban precinct development, together with incentives to reward progressive developers and processes to capture and distribute knowledge gained (these will be discussed in Part 3), will help to encourage greater uptake of low carbon and carbon neutral urban development.

Finding new ways of encouraging low carbon innovation within the urban planning and development context will greatly assist cities in reducing emissions, improve urban carbon management, and can provide an opportunity to challenge and change existing, carbon and resource intensive patterns of land development.

Dr Vanessa Rauland is a lecturer and project coordinator at Curtin University Sustainability Policy (CUSP) Institute. She recently completed her PhD on “decarbonising cities”. Dr Rauland is the co-founder of SimplyCarbon, which helps to reduce organisations’ carbon footprint and improve the efficiency of their operations.

A full list of references can be found in Dr Rauland’s PhD thesis, Decarbonising cities: certifying carbon reduction in urban development.

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