Reducing CO2 emissions
The fired brick industry is responsible for 37% of CO2 emissions from combustion in Nepal, dangerous air pollution and is a major source of black carbon (World Bank, 2020).
In Nepal poor families dream of living in a safe, brick house. After the devastating 2015 earthquake and heavy floods in 2019 more than 800,000 homes were destroyed, and the need for low-cost housing and bricks is higher than ever.
Climate-friendly bricks
Build up Nepal has optimised Compressed Stabilized Earth Bricks (CSEB) for construction in Nepal. Interlocking CSEB, or eco-bricks, are made by mixing and compressing soil, sand and minimal cement in a manual machine. The bricks are stacked and cured (watered) for 21 days – no burning or fuel is required. Eco-bricks are made locally, reducing transportation and creating jobs. Each eco-brick house saves up to 9.5 tonnes of CO2.
Fired bricks - a climate catastrophe
- Coal is transported from India to Nepal.
- The coal is burned in a traditional brick kiln with poor filtration and environmental performance.
- To make the bricks the soil around the brick kiln is dug away and the immediate environment and eco-system is destroyed.
- The bricks are then transported several hours up the Himalayas on very poor roads, breaking 20-40% of the bricks on the way (wastage).
- Child labor and poor working conditions are widespread in brick kilns in Nepal – reported by The Guardian and The Himalayan Times
Coal-fired bricks dominate construction in South Asia, and demand is increasing by 5% each year (World Bank). Yet brick production in Nepal, Bangladesh, India, and China generates 640 million tons of greenhouse gas emissions annually, accounting for 37% of Nepal’s CO₂ emissions, 17% in Bangladesh, and 6% in India.
Interlocking eco-bricks
- Interlocking eco-bricks are made by mixing local soil and sand with cement. The mix is compressed in a manual machine. The main climate effect is the cement used (10%), which is usually made in Nepal and transported to the village by truck for 2-12 hours.
- Soil is sourced locally and sand is transported to the production site (usually 1-10 km) on small tractors/trucks carrying 1-10 ton depending on road conditions.
- The production is done on small scale. Fertile top-soil is cannot be used and when extracting soil it is common to build terraces for farming or use left-over soil from road construction
- 50% less cement and sand is used for mortar in the construction as interlocking eco-bricks are hollow interlocking and the mortar is poured in holes through the bricks without thick layers of mortar in between the courses of bricks.
Compared to fired bricks, interlocking eco-bricks slash CO2 by 75% and air pollution by 90%, cut construction costs by at least 25% and are disaster-resilient.
How big is the CO2 saving?
On average a small 3.5 room house saves 4.58 tonnes of CO2 emissions compared to fired bricks. The world-renowned research institute on earthen structures – Auroville Earth Institute – have made research showing that walls built by earth bricks are emitting 4 times less CO2 compared with fired bricks. (56.79 Kg per m3 compared to 230.06 Kg per m3 for Kiln Fired Brick)
Read more on their website. http://www.earth-auroville.com/compressed_stabilised_earth_block_en.php
Based on this and on research on fired bricks in Nepal conducted by MinErgy in 2013 we can compare the emissions for building a small house.
*All quantities of material is based on Nepal National Building Codes.
** All KgsCO2/m3 data is based on values from Auroville Earth institute