Construction material emissions need focus in low-carbon buildings: Experts

Bangladesh needs to look beyond energy efficiency in buildings and account for the carbon emissions generated throughout the lifecycle of construction materials, including their production, transportation and use, experts said at a seminar yesterday evening (13 August).

While speaking at the seminar, titled "Engineering Low-Carbon and Bio-Based Buildings: From Material Characterisation and LCA to EPD and Building Performance," they stressed greater use of low-carbon and bio-based construction materials, as the country seeks to make its rapidly expanding infrastructure sector more sustainable and climate-friendly.

Engineer Khan Manjur Morshed, vice-president of the Institution of Engineers, Bangladesh (academic and international), chaired the seminar organised by the IEB at the Shaheed Engineer Bhaban at IEB headquarters in Ramna, Dhaka, says a press release. 

In his opening remarks, Khan said scientific research and technological innovation have significantly improved human life, but the benefits of any invention depend largely on how and for what purpose it is used.

Citing the example of dynamite, he said the technology once brought major changes to mining, road, railway and infrastructure construction, but was later also used in warfare and destruction.

He also highlighted the social consequences of excessive and uncontrolled use of information technology.

"Technology has made our lives easier, but excessive dependence on it can weaken social interaction, family bonds and direct human relationships," he said.

Material engineering becoming increasingly important

Prof Engineer Md Sabbir Mostafa Khan, IEB honorary general secretary and Dhaka Wasa chairman, delivered the welcome address, saying construction materials and material engineering will become increasingly important in the future practice of civil engineering.

"The safety, durability and environmental performance of infrastructure largely depend on selecting the right construction materials and understanding their engineering properties," he added.

He noted that construction practices have changed significantly over time, moving from stone, timber and locally available materials to high-rise buildings supported by advanced construction technologies.

According to him, the development of modern buildings has been made possible through innovations in construction materials, structural analysis, earthquake engineering and modern construction techniques.

He also stressed the need to assess local weather and climate characteristics before developing roads and other infrastructure, particularly in coastal areas.

Cement emissions raise concern

Prof Engineer Tanvir Manjur, chairman of the Board of Accreditation for Engineering and Technical Education, spoke as a distinguished guest at the seminar.

He said concrete, steel, bricks and cement remain the dominant materials used in permanent buildings in Bangladesh, adding that lightweight houses made of tin, bamboo, timber and other locally available materials remain common in rural areas.

"Against the backdrop of climate change and the global need to reduce carbon emissions, we need to rethink our conventional construction practices," he said.

Tanvir pointed out that significant carbon dioxide emissions are generated during cement production, particularly through limestone calcination and the high-temperature kiln process involved in clinker production.

The cement industry is associated with around 7–8% of global greenhouse gas emissions, he said.

Therefore, reducing emissions from buildings cannot be limited to cutting electricity consumption during their operational phase, he added.

"Embodied carbon – the emissions associated with producing and supplying construction materials – must also be incorporated into the assessment of low-carbon buildings," he said.

National Housing Authority Chairman Most Ferdousi Begum was also present at the seminar.

Carbon assessment should begin at design stage

Eshrar Latif, associate professor at the Welsh School of Architecture, Cardiff University, UK, presented the keynote paper.

He said buildings consume substantial amounts of energy and raw materials not only during construction but throughout their operational lifecycle.

"Assessing only electricity consumption during the operational stage does not provide the full picture of a building's carbon footprint," he said.

Emissions associated with the production and transportation of cement, steel, bricks, glass and other construction materials also contribute to the overall environmental impact of buildings, Eshrar said.

He stressed that material selection, construction methods and energy management should be considered from the earliest stages of building design.

Eshrar highlighted the potential importance of Life Cycle Assessment (LCA), Environmental Product Declarations (EPD) and building performance assessments in developing more sustainable construction practices.

Need for long-term approach

The seminar was moderated by Engineer Nesar Uddin, secretary of the IEB's Civil Engineering Division.

Engineer Muhammad Ahsanul Russell, IEB honorary assistant general secretary (administration and finance), members of the IEB Central Council, leaders of engineering divisions and engineers from various government agencies and departments also attended the event.

Speakers said Bangladesh's rapid urbanisation and infrastructure development have made it increasingly important to address emissions from the construction sector through long-term planning.

They said environmental impacts should be assessed across the entire lifecycle of a building – from design and material production to transportation, construction, operation, demolition and potential reuse or recycling of materials.

They also called for greater research, standardisation and adoption of low-carbon and bio-based construction materials.

Such a shift, they said, could help Bangladesh reduce the climate impact of its growing construction sector while creating a pathway towards more resilient and sustainable infrastructure.