Construction activity and production of building materials contribute heavily to greenhouse gas (GHG) concentration in the atmosphere and in turn to global warming. The Global Status Report 2022 by the United Nations Environment Programme (UNEP) highlights that the share of CO2 emissions by the building and construction industry is a huge 37%, including material manufacturing, which alone is accountable for 11% of the emissions. During the lifecycle of a building material, carbon emissions happen at various stages such as extraction, manufacturing, transport, construction and disposal.
Due to the irreversible nature of carbon emissions, building professionals bear a crucial responsibility to manage the embodied carbon of buildings, largely determined by material choices.
Sustainable materials and technologies have proved to have significantly lesser impact on the environment during their production and life cycle as compared to conventional materials. In addition to the benefits of lesser embodied energy and carbon, a material that has the potential to be salvaged and reused can reduce the demand for fresh resource extraction and pave the way for a circular economy—wherein the idea of waste is eliminated, and materials are continuously cycled back into the system. For instance, recycling aluminium, if compared with the production of primary aluminium products, needs as little as 5% of the energy and emits less than 5% of GHGs (International Aluminium Institute 2009). Life Cycle Assessment (LCA), developed since the 1960s, enables the determination of a building’s Global Warming Potential (GWP) by analyzing the GWP of all constituent materials throughout their lifecycle, thus defining their embodied carbon. Informed decisions by building practitioners can be vital in the climate action.
However, there have been challenges in the adoption of sustainable building materials and even today the high embodied carbon materials are widely used in the market. It is vital to understand these roadblocks as we aim to switch to a net zero building and construction sector:
- Perception of High Costs: Low carbon materials and technologies are commonly talked about in terms of their environmental benefits but not about their economic benefits. They are often seen as an expensive endeavour that involves upfront investment in ‘green specification and technology’. Procurement decisions in projects are predominantly based on upfront capital cost. This approach refrains project teams from adopting sustainable technologies and materials. However, it is important to note that the selection of materials and technologies should not just be based on the capital cost, but also based on the operational cost, the temporal accuracy and the payback periods. Therefore, to understand the economic benefits of such technologies, it is important to conduct life cycle cost analysis.
- Performance Concerns: The perceived gap in performance, durability, and safety between some low-carbon materials and traditional ones contributes to hesitation among clients and construction professionals.
- Data Gap: The gap in data availability regarding the LCA and LCC numbers of materials and technologies leads to reluctance in adoption of new materials and technologies in the market, even if they offer environmental benefits. LCC considers the operational and maintenance factors throughout the procurement process. The LCC of a building is done to recognize the business case for optimization of the whole life value of the building design and systems to ensure economic sustainability.
- Lack of Strong Incentives: Industry adoption of low-carbon materials is hindered by the insufficient enforcement of regulations and a shortage of financial encouragement.
- Supply Chain Issues: Potential disruptions and complexities stem from the less mature supply chain of low-carbon materials compared to established conventional material networks.
- Lack of Early Engagement: The absence of early stakeholder engagement during the design process can hinder the effective deployment of low-carbon solutions.
As we move towards prioritizing embodied carbon in green buildings, it’s crucial to examine why it has been historically overlooked. A consistent approach to embodied carbon measurement necessitates active involvement from every building industry stakeholder in the ways suggested:
1. Government:
- Implement policy mandates requiring the adoption of LCA.
- Establish regulations that demonstrate measurable reductions in carbon emissions compared to conventional construction.
- Develop material directory of low carbon materials and case studies of projects using it through partnership with researchers and ratings agencies. Such a data set available in public domain will garner trust of users in using low carbon materials.
- Launch labelling schemes (such as BEE star labelling) that give information about materials and their efficiency.
- Embed the use of low carbon materials as a part of tendering process for all centre and state projects.
2. Researchers:
- Develop comprehensive Global Warming Potential (GWP) databases, prioritizing the Indian context due to current data limitations.
- Address the process-dependent nature of GWP data through detailed research.
3. Building Practitioners (Architects, Consultants, Developers):
- Enhance professional skillsets to effectively implement and advocate for LCA.
- Equip practitioners to accurately assess and communicate the carbon emissions of projects to clients.
3. Supply Chains:
- Streamline supply chains to prioritize and promote materials with verified LCA data.
- Encourage transparent product labeling with clear emission numbers.
4. Rating Bodies:
- Bridge the gap between demand and supply of LCA-assessed materials.
- Utilize rating systems to incentivize LCA adoption, as demonstrated by GRIHA’s integration of LCA criteria.
- Continue to increase the demand for products with LCA data, similar to the previous increases in demand for other green products that GRIHA has achieved.
5. Clients and the Public:
- Increase public awareness of the climate impact of building material choices.
- Ensure easy and affordable access to sustainable building materials.
6. Public-Private Bodies:
- Actively developing public-private partnerships will significantly aid in the funding of sustainable construction.
- Green bonds, carbon credits, impact investments, and other innovative financing solutions can effectively generate funding for sustainable construction projects.
The transition to a net-zero construction sector requires a transformative change in our approach, placing equal importance on the carbon embedded in materials and the emissions produced during building use. We need to stop thinking of sustainable materials as mere luxuries and instead understand their long-term economic and environmental value by conducting thorough Life Cycle Cost Analysis.
With the goal of raising awareness about the environmental challenges posed by building materials, GRIHA (Green Rating for Integrated Habitat Assessment), India’s own green building rating system, seeks to equip the industry and masses with the knowledge needed to make eco-friendly choices. The inclusion of specific criterion on the use of alternative materials, LCA and LCC in GRIHA rating system is with the aim to encourage the building and construction industry make a responsible choice in line with GRIHA’s motto—”what gets measured, gets managed”. Product catalogue has been developed to provide green building designers and clients with all necessary information on green building products which can be used to make buildings low carbon.
The combined efforts of governing bodies, research institutions, building professionals, supply networks, assessment organizations, and the public are absolutely necessary for a sustainable future. By nurturing a culture of responsibility and ingenuity, we can align supply and demand, encouraging the use of low-carbon materials and technologies. We must act now, because the world we create today will be the world we live in tomorrow.
