The cost of building construction could be brought down by 25 per cent with the use of eco-friendly materials like hollow blocks, instead of traditional bricks, according to a study of the House Building Research Institute (HBRI).

The study titled “The cost-benefit analysis of using hollow block in modern building” was conducted by HBRI in recent months.

According to the study, countries like China, Vietnam, and Indonesia have already started to use a combination of sand, cement, and stone-made blocks, instead of traditional bricks, to reduce any harmful environmental impact.

“These blocks are made of river sand, cement, and small pieces of stones. These blocks needn't be burned. That's why they are environment-friendly,” said Akhter Hossain Sarkar, a senior research officer of HBRI.

The sound and heat protection capacity of these blocks are higher than that of traditional bricks. The lightweight, saline, and humidity-protective nature of the blocks ensures longevity, Sarkar said.

The HBRI official also said that the cost of building construction could be brought down 25 per cent with the use of these hollow blocks. “Each piece of hollow blocks costs Tk. 30–35. A piece of hollow block is 4.5 times bigger than a traditional brick. So, it will reduce the construction cost,” he added.  

A number of local builders have already started using these blocks for construction of buildings. As many as 20 block factories have already been set up for this purpose. Concord, one of the top real estate companies, has been using hollow blocks since 1998.

 Concord general managing Shamir Uddin Ahmed said: “Concord use hollow blocks in all the buildings we construct. So far, such blocks have been used in 500 buildings constructed by our company.”

 Initially, the cost for hollow blocks was comparatively higher than bricks, but the situation has changed now, he added.

 The cost for a piece of hollow block is Tk. 35, while the cost of the same quantity of bricks is Tk.10–15 higher than the blocks. Besides, it also saves other ingredients like cement and sand which are required for wall plastering.

Traditional bricks, however, are still used in most of the building construction mainly due to the lack of awareness and knowledge among people.

Bangladesh Brick Manufacturer Owners' Association president Mizanur Rahman Babul said they are aware about the use of hollow blocks instead of traditional bricks. “But the low demand of hollow block is still a big problem as most people use bricks for building construction.

These blocks are yet to be used in government's development projects—this is refraining brick manufacturers from starting block production,” he added.

Babul also said that they recently visited such a project in India and were given a machine for making blocks at free of cost. For collecting the required fly ash for test production, an application was sent to the power ministry through the environment ministry.

 “We are yet to get any reply from the power ministry. We could not start the production of hollow blocks just because of the fly ash crisis,” he added.