Gaining Sustainability in the Construction Industry: Integration of Life Cycle Assessment (LCA) into Building Information Modeling (BIM)

1.0.    Introduction

The concept of sustainable development has increasingly amassed attention globally. In fact, a report that was published by the World Commission on Environment and Development (WCED), called for an approach that merges construction projects and the environment so as to sustainably meet the needs of the present without jeopardising the capability of prospective generations to address their own needs (Ortiz et al. 2009). The United Nations (2015) also maintains that the primary challenge of the 21st century would be sustainable development. Thus, implementing sustainable development projects is key to protecting the “already depleted” environment while meeting and securing the future of posterity.  

The discourse on economic, social, and environmental elements of sustainable development is currently focusing on the construction sector; an internationally emerging industry, and a relatively active enterprise in both developing and developed countries (Ortiz et al. 2009). For instance, according to European Commission (2017), around 14 million people are directly employed by the construction industry and it is Europe’s leading industrial employer, representing 7 percent of the entire employment and 30 percent of sectoral employment in Europe. Besides, more than 900 billion euros was spent on construction in 2013, representing 10 percent of the region’s gross domestic product (GDP). However, environmentally, the construction industry has been implicated for high-energy usage, greenhouse gas emissions, solid waste products and other forms of environmental pollution (Ortiz et al. 2009). In view of these facts, there is a need to incorporate innovative and sustainable solutions into development projects to minimise the environmental depletion caused by the construction industry.

Building Information Modeling (BIM) and sustainable construction comprise the two most trending and growing concepts in the construction sector. The BIM is a new technology used in construction design in which a digital image of the building activity is used to aid in the exchange of data in digital form (Porwal & Hewage 2013). It is an approach used to manage construction design and project information in digital layout during the entire project’s life cycle.

Life cycle assessment (henceforth referred to here as LCA) is also another approach that is used to make informed decisions during the initial construction design phases. In construction project context, LCA is a tool used for critical assessment of the environmental implications arising from buildings throughout their life cycle (Han et al. 2013). LCA assessment incorporates environmental implications from building material acquisition to construction, building use and ultimate demolition. It takes into consideration all the project costs, from ownership to the disposing of a structure.  However, even though the application of LCA in sustainable construction projects has been widely implemented, the model has often been used as ‘stand-alone’ tool. The application of LCA as an independent system presents a barrier to a functional inclusion of other possible approaches to implementing sustainable construction. In order to overcome this problem, this study proposes the integration of life cycle assessment (LCA) into BMI particularly in relation to decision making so as to support the course for sustainability within the construction industry.

1.1.      Research Problem Statement

Despite the booming growth in the construction enterprise, the sector faces new challenges. The society is demanding for a reduction in energy and resource consumption, and execution of sustainable buildings. There is a fundamental need for a shift in construction industry's focus from a cost-based approach into a value-based one (Ortiz et al. 2009).The LCA has previously been applied in development projects to improve the sustainability of buildings and to mitigate environmental damage caused by the construction industry. However, the LCA has only been used as a lone technique to addressing sustainability challenges and this limits the incorporation of other methods that could significantly contribute to sustainability in the construction industry. In view of the stated challenge, the author of this project believes that the integration of Life Cycle Assessment (LCA), with BIM, could go a long way to foster decision-making processes involving mitigation of buildings’ environmental damage and realising the sustainable design.         

1.2.      Research Aims and Objectives

1. To investigate the nexus between BIM strategies and environmental data contained in the LCA databases.
2. To examine the construction project phases which can have the most impact in relation to realising sustainable construction

• To evaluate the properties of both LCA and BIM approaches and to analyse at which phases both methodologies can be optimally merged.

2.0.    LITERATURE REVIEW

2.1.      The concept of sustainability in construction sector: The LCA model

According to Hopwood et al. (2005), ‘sustainable development’ can be defined as improving the quality of life and therefore allow individuals to inhabit in a safe and healthy environment while enhancing the economic, social and environmental well-being for both the present and succeeding generations. Within the context of construction projects, the terms sustainable development, high performance, green structures, and sustainable construction are usually used interchangeably (Kibert 2008). However the phrase ‘sustainable construction ’in most cases extensively deals with the economic, ecological and social element of a constructed building in the context of the community. With the increasing consciousness of sustainability issues, several tools have been made to evaluate sustainability from various perspectives. One of these tools is the life cycle assessment model (LCA).

Ortiz et al. (2009) contend that the development of LCA model has been relatively slower in the construction sector than in other industries, even though it was first actualised in the early 90s. Whereas the guidelines given in the different LCA benchmarks apply to industrialised operations, Arena & De Rosa (2003) argue they do not fit quite well in building projects due to a variety of special attributes. For example, the same authors believe that the long life cycle of builds and the fact that each product is inimitable significantly affects the applicability of LCA in the construction field. On the contrary, the construction industry is increasingly applying the LCA approach into decision-making processes in the quest to optimise the entire construction process (Antón & Díaz 2014).

Apart from the LCA model, there are other approaches that can be used to assess the environmental effects of buildings, for instance, Life Cycle Energy Analysis (also known as LCEA) and Life Cycle Cost Analysis (also called LCCA). Contrary to LCA, the LCEA is concentrating more on the energy consumption of a construction during its entire life cycle, including the operating and demolition energy, and the total energy used in the building is what is called the life cycle energy (Cabeza et al. 2014). Project engineers and that utilise LCEA method can easily determine the phases that consume the most energy, thus enabling them to make more appropriate choices on the best energy efficient materials to use. The LCEA method can also measure greenhouse gas emitted through the main energy of a building by multiplying it by a certain factor. However, LCA method offers more accurate and reliable outcomes (Ramesh et al. 2010), due to the fact that with this approach, the building’s environmental impact is analysed from the start of the assessment.

2.1.1.  Benefits of LCA as a decision-making guide

 As had been mentioned in the previous section, LCA is highly used for guide decision-making process in the early phases of a construction project phases. It can help in material selection, offer support when comparing different options, guide the organisation of the procedure for residues disposal and help in the creation of the construction schedule. It also gives guidance on how to enhance environmental performance in the entire life cycle of a building. The LCA also makes it easy to analyse the environmental performance of various construction and to gain knowledge from this experience (Ortiz et al. 2009). Besides, a broad scope of environmental elements can be assessed in addition to energy usage. The LCA has been found to help in cost reduction because it minimises environmental costs and thereby contributing to a reduction in consumption of both energy and resources (Ortiz et al. 2009). LCA helps in increasing in social consciousness on environmental effects. Therefore all the construction project stakeholders including the community have to be aware of the implications of environmental impacts have.

2.1.2.  The challenges of using LCA independently

One of the primary limitations of using the LCA tool is that one has to be a data entry expert to run the software, unlike BIM which is user-friendly. Also, LCA has been know to consume a lot of time. Furthermore, in some cases, there may be insufficient data or the available information may have lost value. These challenges could result in assumptions that might render the LCA assessment inaccurate (Han et al. 2013). As matter of fact, there is even no benchmarking or a universal methodology on how to rank LCA performance. Even though ISO requirements of LCA gives a basic framework, it does not, in fact, provide a systematic methodology.

A building usually comprises of a variegated class of products, and each of those products has its unique features, life span and ecological effects. This combined with the uncertainty about the premise’s future make it very almost impossible to conduct LCA evaluation the entire building as a single entity. Another problem is the misuse of LCA due to its implementation in the late phases of the project.

All the challenges highlighted above are associated with the complexity and costs of using LCA tool independently. Thus the LCA tool needs advanced development if it has to be successfully applied as decision-making support guide. In a nutshell, the LCA approach has several limitations which could possibly be solved by optimising it with BIM.

2.2.      Optimisation of LCA using BIM

According to Antón & Díaz (2014), sustainable development in the construction sector largely depends on realising minimal ecological impact and at the same time spurring both economic and social progress. Presently, the sector is not quite efficient owing to a lack of sufficient collaboration efforts and blatant waste of resources. Hence there is a need for change as far as these issues are concerned. Optimised design can be achievable through the integration of innovative tools such as BIM and LCA. The advantage of this approach is that it directs attention, efforts and resources to the initial design stages; this means an increased ability to impact the project.

The BIM has been identified as a significant contributor to building sustainability because it can foster the execution of an integrated design. The tool has an enhanced capacity for data management and fosters cooperation of various stakeholders engaged in the construction project from the initial design stages going forward. This gives a snapshot of the task, and the construction sector can, therefore, perform in a more effective manner (Antón & Díaz 2014).

One of the limitations with using LCA as a lone tool is, in fact, the manual re-entry of the project information into the tool. This is one of the major challenges that needs be addressed (Antón & Díaz 2014). According to Antón & (Díaz 2014), successfully optimisation of LCA using BIM, would go a long way to resolving the manual re-entry of issues of data because it is believed that the LCA models could easily access BIM data. The BIM tools have data on the project cost and can, therefore, help in cutting down on project cost in sustainable construction design because they give the essential data and evaluates it. It is thought that the BIM’s ability to improve construction sustainability could be achieved via integration with LCA model. BIM has promising prospect in terms of realising sustainable design, however, presently this potential has not been fully tapped. Ortiz et al. (2009) attribute the lack of interoperability as the main hindrances to the realisation of BIM’s full potential. The potential of BIM as far as sustainability is concerned could be improved by synergising with LCA.

Antón & Díaz (2014) provide two approaches to integrating LCA with BIM. According to these authors, the first strategy involves mining the project data directly from the BIM too and utilising it to carry out an LCA analysis of a building project throughout its life cycle. Since the BIM system is employed as the main data source, this avoids the cumbersome data re-entry which is often done manually. The other suggested technique is based on carrying out LCA analysis of premises that have been developed using the BIM tool. The advantage of this approach is that it can be used to carry a comparative analysis between projects that have been completed using LCA-BIM integrated approach and those that have been done using only BIM.

3.0.    METHODOLOGY

The primary g this goal of this study is to propose a methodology for integrating LCA into BIM in construction projects to ensure sustainability in the construction industry. The aim is to identify the relationship between BIM and LCA in relation to environmental analysis. The project also aims at offering the theoretical basis for optimised construction design also offer recommendations on which phase LCA-BIM integration produces optimal results. Data collection will be carried out by way of qualitative technique and the research methodology that will be in this work will include a survey of relevant literature, comparative studies, inductive reasoning and interviews.

3.1.      Literature review

The data to be used in this work will mainly be collected through an extensive survey of the literature, in the quest to evaluate the current state of LCA-BIM integration concept in relation to sustainability. This will help in giving an understanding as well as defining the implications, driving factors and merits of LCA-BIM collaborative application, and also as pinpoint the barriers and constraints of the existing practices. The sources for the materials to use in literature survey include several research articles, books, conference proceedings, scientific papers, scholarly publications, handbooks, websites of various construction firms and regulatory agencies. The author of this study will ensure that the information used is objective and of the highest integrity.

3.2.      Comparative analysis

  Through the utilization of the comparative studies, various interrelated objective elements will be compared, so that objective conclusion, about merits and demerits, can be drawn. For example, this project will comparatively analyse the conventional and the LCA-BIM integration methods, in order to ensure that concerns relating to existing practices are pointed.

3.3.      Inductive reasoning

            Ketokivi & Mantere (2010) perceives inductive reasoning a basic element of human intelligence. It starts with certain observations and actions, which then results in the identification of particular patterns from which certain hypotheses can be drawn and tested, which would ultimately lead to a general conclusion. In this work, inductive reasoning will be utilised to reason specific design decision-making aspects, which result in the detection of patterns conducive for collaboration during the initial design phase. 

3.4.      Interviews

Interviews comprise one of the most popular techniques of qualitative data gathering. Interviews will also be utilised in this project to find out about the set of knowledge and perspectives of different people, with the aim of having a deeper understanding in some of the interoperability issues between LCA-BIM sustainability analysis and environmental performance assessment.

3.5.      Expected research results

The author of this project that at the end of the project, concrete recommendations will be provided on the best methodology of integrating LCA into BIM in the context of construction projects. Besides, it is anticipated the project phase at which maximum LCA-BIM can be achieved in a construction project will be identified. Lastly, the finding of this project will be published in peer review journals.