Engineers and architects urged Bangladesh’s construction sector to account for embodied carbon and adopt low-carbon materials, life-cycle assessment and environmental product declarations from design onward.
Buildings in Bangladesh must be designed to reduce not only energy consumption but also the carbon emissions generated throughout the production, transport and use of construction materials, engineering and architectural experts said at a seminar in Dhaka on Thursday.
The experts called for greater use of low-carbon and bio-based building materials and urged the construction sector to incorporate the environmental impact of materials across their entire life cycle into building design and planning.
The remarks came at a seminar titled “Engineering Low-Carbon and Bio-Based Buildings: From Material Characterization and LCA to EPD and Building Performance”, held at the Council Hall of the Shaheed Engineers Building at the headquarters of the Institution of Engineers, Bangladesh (IEB) in Ramna, Dhaka.
The seminar was organised by IEB and chaired by IEB Vice-President (Academic and International) Engineer Khan Manjur Morshed.
In his address as chair, Morshed said research and technological innovation had made people’s lives easier but that the benefits of technology depended on its purpose and use.
Citing dynamite as an example, he said the technology that had once transformed the construction of mines, roads, railways and other infrastructure had later been used for war and destruction.
He also referred to advances in information technology, saying that while technology had made life easier, excessive and uncontrolled use could negatively affect social communication, family ties and interpersonal relationships.
IEB Honorary General Secretary and Dhaka Water Supply and Sewerage Authority (Dhaka WASA) Chairman Professor Dr Engineer Md Sabbir Mostafa Khan delivered the welcome address.
He said construction materials and materials engineering would become increasingly important in the future practice of civil engineering, adding that the safety, sustainability and environmental performance of infrastructure depended largely on selecting appropriate construction materials and understanding their engineering properties.
He said construction practices had changed significantly over time, moving from structures based on stone, wood and local materials to multi-storey and high-rise buildings. This transformation had been driven by innovations in construction materials, together with advances in structural analysis, earthquake engineering and modern construction technology.
He also stressed the need to examine local weather and climate characteristics before developing infrastructure in coastal areas.
BHTE Chairman Professor Dr Engineer Tanvir Manjur delivered a keynote address, saying permanent buildings in Bangladesh were mainly constructed using concrete, rod, brick and cement-based methods.
In rural areas, however, there was a trend towards relatively lightweight houses made from local materials including tin, bamboo and wood.
He said conventional construction methods needed to be reconsidered in the context of climate change and efforts to reduce global carbon emissions.
Manjur said cement production released significant quantities of carbon dioxide (COâ‚‚) through the calcination of limestone and high-temperature kiln processes used to produce clinker. The cement industry, he said, was responsible for about 7 to 8 percent of global greenhouse gas emissions.
Future low-carbon buildings therefore needed to focus not only on reducing energy consumption during operation but also on embodied carbon, meaning the carbon emissions generated throughout the manufacture and supply of building materials, he said.
National Housing Authority Chairman Mosha Ferdous Begum was also present at the seminar.
Carbon accounting at the design stage
The keynote address at the seminar was presented by Dr Eshrar Latif, Associate Professor at the Welsh School of Architecture at Cardiff University in the United Kingdom.
Latif said a huge amount of energy and raw materials was consumed in constructing and operating buildings. Considering only electricity consumption during a building’s use was therefore insufficient to determine its full carbon footprint, he said.
He noted that emissions produced during the manufacture and transportation of construction materials including cement, steel, bricks and glass also formed part of a building’s overall environmental impact.
Latif said reducing a building’s carbon footprint required decisions on materials, construction methods and energy management to be incorporated from the earliest stage of design.
He said approaches including Life Cycle Assessment (LCA), Environmental Product Declaration (EPD) and assessments of actual building performance could play an important role in the future construction sector.
Call for greater involvement of engineers
The seminar was moderated by Engineer Nessar Uddin, Secretary of IEB’s Civil Engineering Department.
IEB Honorary Assistant General Secretary (Administration and Finance) Engineer Muhammad Ahsanul Russell, members of the Central Council, leaders of the Engineering Department and engineers from various organisations and departments attended the event.
The speakers said Bangladesh needed a long-term plan to cut emissions from the construction sector as rapid urbanisation and infrastructure development continued.
They said environmental accounting should cover every stage, from building design and the production of construction materials to construction, use and the recycling of materials at the end of a building’s life cycle.
Increasing research, standardisation and use of low-carbon and bio-based construction materials could help Bangladesh’s construction sector address the impacts of climate change while supporting the development of sustainable infrastructure for the future, they said.
