Life-Cycle Greenhouse Gas Emissions of Commercial Buildings

An Analysis for Green-Building Implementation Using A Green Star Rating System

Cuong N. N. Tran, Vivian W. Y. Tam, Khoa N. Le

• Publisher: Routledge
• Year: 2021
• ISBN:
  9781000409192
• Edition: 1
• Topic: Business
• Subtopic: Real Estate
• Index: Business

This book develops a model to evaluate and assess life-cycle greenhouse gas emissions based on typical Australian commercial building design options. It also draws comparisons between some of the many green building rating tools that have been developed worldwide to support sustainable development. These include: Leadership in Energy and Environmental Design (LEED) by the United States Green Building Council (USGBC), Building Research Establishment Environmental Assessment Method (BREEAM) by the Building Research Establishment, Comprehensive Assessment System for Building Environmental Efficiency (CASBEE) by the Japanese Sustainable Building Consortium, and Green Star Environmental Rating System by the Green Building Council of Australia.

Life-cycle assessment (LCA), life-cycle energy consumption, and life-cycle greenhouse gas emissions form the three pillars of life-cycle studies, which have been used to evaluate environmental impacts of building construction. Assessment of the life-cycle greenhouse gas emissions of buildings is one of the significant obstacles in evaluating green building performance. This book explains the methodology for achieving points for the categories associated with reduction of greenhouse gas emissions in the Australian Green Star rating system. The model for the assessment uses GaBi 8.7 platform along with Visual Basic in Microsoft Excel and shows the relationship between the building's energy consumption and greenhouse gas emissions released during the lifetime of the building. The data gathered in the book also illustrates that the green building design and specifications are becoming more popular and are being increasingly utilized in Australia. This book is important reading for anyone interested in sustainable construction, green design and buildings and LCA tools.

1
Introduction

1.1 Background

The negative impact of climate change is an indisputable issue in the global context (Neil Adger et al., 2005; Rehan & Nehdi, 2005; Damtoft et al., 2008). One of the most significant causes of global warming is the increase of greenhouse gas (GHG) emissions into the atmosphere (Cheung, 2013; Wang & Wang, 2015; Villoria-Saez et al., 2016; Álvarez-Herránz et al., 2017). Anthropogenic GHG emissions comprise approximately 82% carbon dioxide (CO2), 9% methane (CH4), 6% nitrous oxide (N2O), and 3% other fluorinated gases (Crowley, 2000; Intergovernmental Panel on Climate Change (IPCC), 2014).

To protect the global environment, several countries with high GHG emissions have undertaken measures to improve energy efficiency, which might help reverse the uptrend of global GHG emissions since 2012. The methods for the reduction of GHG emissions should be continuously implemented via both legal and technical approaches to enhance the synchronous effects of stalling climate change and austerity (Olivier et al., 2016). To deal with the tremendous impacts of rapid global warming, governments should synchronize laws, standards, and tools to protect the environment against public nuisances as well as private interference (Wong et al., 2012; Cheung, 2013; Percival et al., 2017). One of the reasons for the rising trend of GHG emissions is the boom of global economy, to which the construction industry has been contributing significantly (Van Vuuren et al., 2017).

Green buildings have recently gained popularity due to many reasons. Numerous studies exist that focus on a variety of aspects of green buildings. However, according to Cassidy et al. (2003), green buildings are defined as buildings that have an increased usage efficiency of energy, water, and materials, such as concrete and steel. Moreover, green buildings have reduced adverse impacts on human health and environment through better planning, design, construction, operation, maintenance, and demolition throughout the complete life cycle of the building. Many studies provide similar definitions for green buildings (ASHRAE, 2006 p. 4; United States Green Building Council, 2007; Hoffman & Henn, 2008; Robichaud & Anantatmula, 2011; United States Environment Protection Agency, 2014; World Wildlife Fund, 2015). Considering all these requirements for green buildings, evaluating them has been a consistently challenging task.

Identifying the extent to which green buildings cater to these requirements is central to their evaluation and has led to the development of many green building rating tools overtime. Green building rating tools assess buildings and act as a reliable measure in the evaluation of the building for sustainability (Eichholtz et al., 2010). Green building rating tools have been developed, representing many countries and regions, giving priority to country-specific requirements (Illankoon et al., 2017a). The first green building rating tools were launched in 1990 in the UK under the name of Building Research Establishment Environmental Assessment Method (BREEAM) (Building Research Establishment Environment Assessment Method, 2015). Thereafter, the most discussed and widely used green building rating tool was launched by the United States Green Building Council (USGBC) named Leadership in Energy and Environmental Design (LEED) (United States Green Building Council, 2015). In Australia, Green Star is the most widely used green building rating tool (Green Building Council Australia, 2018).

Green Star comprises a set of rating tools developed to evaluate various green initiatives. “Green Star – Design & As Built” version 1.1 is the latest Green Star rating tool used to evaluate buildings and significant refurbishments (Green Building Council Australia, 2018). There are nine key environmental criteria illustrated in the Green Star – Design & As Built version 1.1, namely, management, indoor environment quality, energy, transport, water, materials, emissions, land use and ecology, and innovation. Each of these crucial criteria has credits, illustrating specific requirements that the building under evaluation should follow, and specific credit points are attributed if the criteria are fulfilled. Once the credit requirements are achieved, the relevant number of credit points is allocated to the evaluated building. Finally, total credit points are calculated to arrive at the final score. On the basis of the final score, a certification is awarded according to the Green Star certification criteria. However, many interdependencies among these credits exist, including credits that represent different key criteria (Tam et al., 2018a). Therefore, when considering the challenges posed by green buildings, these credits should be considered collectively in decision-making.

Life-cycle GHG emissions assessment is one of the major challenges in the evaluation of green building performance (González & García Navarro, 2006; Winston, 2010; Ahn et al., 2013). However, many scientists claim that lack of sufficient studies concerning GHG emissions considerations is the primary issue, because of lack of analyzed inventory data for environmental performance in construction field (Kawai et al., 2005; Nicol & Chadès, 2017). Therefore, life-cycle GHG emissions assessment needs to be considered during the early phases of green building projects to achieve better green building design options. According to the International Organization for Standardization (2006), life-cycle GHG emissions estimation considers the building’s lifespan, including material production, construction, operation, and its final phase (which includes disposal and/or recycling phases) (Al-Ghamdi & Bilec, 2016; Tam et al., 2018b).

Considering all the aforementioned factors, it is essential to demonstrate that co-dependent credits related to reduction of GHGs should be carefully studied, as these credits are expected to lead to optimal designs for green buildings. Furthermore, when analyzing these credits, it is crucial to focus on the life-cycle GHGs rather than studying environmental impacts of GHGs produced at separate stages within the building’s life cycle. Therefore, this research aims to identify optimal solutions to green building designs considering life-cycle GHG emissions in terms of Green Star credits.

1.2 Research aim and objectives

The aim of this book was to adopt a life-cycle GHG emissions assessment model based on a set of Green Star credits for commercial buildings in Australia. To satisfy the goals of this research, the following objectives were identified:

1. Critical reviews of sustainable development, green building rating tools worldwide, and techniques to analyze life-cycle GHG emissions in green buildings, which include the following:
   1. Reviewing sustainable development goals and green building concepts.
   2. Reviewing the development of life-cycle assessment in the construction sector.
   3. Reviewing green building rating tools from global and Australian perspectives.
   4. Examining model technique development in life-cycle assessment.
   5. Analyzing life-cycle GHG emissions assessment in green buildings.
2. Reviewing and classifying the Green Star – Design & As Built rating tool and describing the methodology to develop a model for GHG emissions assessment:
   1. Reviewing the Green Star design rating tool in Australia and determining the credits in this rating tool related to life-cycle GHG emissions.
   2. Analyzing the process of model development for the life-cycle GHG emissions assessment.
3. Discussing environmental impacts of model parameters:
   1. Discussing the environmental impact of commercial buildings’ envelopes with respect to climate zones in Australia.
   2. Discussing the environmental impacts of materials for green buildings.
4. Validating the life-cycle GHG emissions assessment model and determining optimal options for achieving credit points in the Green Star rating tool for Australian commercial buildings by employing case studies of buildings that were awarded the Green Star certificate.

1.3 The significance of the book

To fulfill the needs of the future, the Australian building sector seems to be advancing toward sustainable design. The Green Star Environmental Rating System is one of many green building rating systems that have been employed worldwide, and is currently the only Australian nationwide and voluntary rating system for the green construction (Tam et al., 2017b).

The significance of this research lies in the estimation and implementation of the flexible and straightforward process of life-cycle GHG emissions assessment for typical building fabrics and primary materials that constitute the structural materials of a commercial building in Australia and their adaptation with the Green Star rating tool. The research develops a model that can be conveniently modified to automate calculations for credits under Green Star to reduce the amount of GHG emissions during the building’s life-cycle, inventively reducing tedious manual estimations, which have chronically plagued the Australian construction industry. The research also illustrates the proof of popularization of green building design and its specifications, which are being increasingly utilized in Australia.

1.4 Research methodology

The methodology of the research presented in this book includes four stages and is further divided into logical steps, as shown in Figure 1.1. The first stage includes literature review and determination of the research problems, aims, and objectives.

Figure 1.1 Schematic representation of the research progress

The second stage of the research involves the analysis of main associated elements and processes in the construction project, and selection of the credits related to the reduction of environmental impact in accordance with Green Star. This stage identifies the constraints and variables for the model analysis.

The third stage concentrates on the development of the life-cycle GHG emissions assessment model. The model uses GaBi 8.7 software to assess the life-cycle impact of each element in a building. Then, the unit results obtained are used to calculate the breakdown quantities from design. The results are ultimately consolidated in MS Excel and Visual Basic and employed to select optimal design options to achieve most Green Star credit points.

Finally, the fourth stage discusses environmental impact assessment and validation of the model. The proposed life-cycle GHG emissions assessment model is validated by evaluating three Green Star-granted buildings in Australia. These buildings (used for the case studies) are located in three different states in Australia. Detailed information on them is provided in Chapter 5.

1.5 Scope of the book

Book study proposes a life-cycle GHG emissions assessment model for an office building in Australia. The intended life-cycle GHG emissions assessment model complies with the guidance of the Green Star rating tool (Design and As Built) to achieve credit points with regard to GHG emissions reduction. The environmental impact (including global warming potential, ozone depletion potential, photochemical ozone creation potential, eutrophication potential, aquatic ecotoxicity, terrestrial ecotoxicity, acidification potential, and human toxicity potential) of major materials referred in Green Star and envelope alternatives of a typical office building in Australia are assessed to find the optimal design solution associated with the lowest amount of life-cycle GHG emissions.

1.6 Book structure

Chapter 1 presents the introduction of the study. This chapter con...