The interlocking bricks being checked

Haileybury Youth Trust is a charity training young people in Uganda to build sustainable buildings using interlocking blocks made from stabilised, compressed earth: a low-cost, carbon-saving alternative to the environmentally damaging fired brick.

As well as preventing deforestation and drastically reducing CO2 emissions, the buildings are transforming communities, including sanitation facilities, affordable housing and new school buildings, whilst simultaneously being sympathetic to the surrounding landscape. HYT aims to “provide a hand-up, not a hand-out” and the skills that the young people are learning are creating employment opportunities in one of the fastest growing populations in Africa.

The benefits of this scheme go way beyond the environmental impact – reducing deforestation and curbing CO2 emissions through a low carbon building technique – and encompass health, training and employment opportunities, even access to education. HYT’s model is a simple one but is scalable and robust.

2017 Ashden Judging Panel

Context

Uganda has one of the fastest growing populations on earth, resulting in an increasing requirement for new housing, schools and other infrastructure. Approximately 80% of the population is younger than 30; many of these young people lack employable skills and youth unemployment is a growing problem.

The traditional hand-moulded fired brick used for building, with its reliance on local trees to fuel the brick-making kilns, is one of the biggest contributors to the destruction of Uganda's forests. As tree cover decreases and the population increases, the price of the fired bricks continues to rise, while their quality falls. 

Requiring no firewood and less cement, Interlocking Stabilised Soil Blocks (ISSBs), a compressed earth brick, are an economic and low carbon alternative. Training young people in building with ISSBs provides them with masonry skills and the ability to find employment, as well as widening awareness of ISSBs, while preserving fragile Ugandan biodiversity.

Interlocking Stabilised Soil Blocks (ISSBs), a compressed earth brick, are an economic and low carbon alternative

How Haileybury Youth Trust works

HYT is a charity which trains young people in sustainable building construction and is also a social enterprise, constructing low carbon, sustainable buildings for local and international clients.

HYT works directly in Ugandan communities providing vocational training to local young people who build good quality structures using ISSBs within their community. The structures include affordable housing, latrines, washrooms, kitchens, school dormitories and classrooms, and rainwater harvesting tanks.

HYT will only work where there is a clear demand from the local community, an availability of potential trainees and a commitment to maintain the buildings in the future. To promote ownership and community engagement, communities also participate by providing food and shelter for trainers and trainees and safe storage for construction equipment. Following completion, the buildings are inspected periodically to ensure correct usage and maintenance.

Candidates for training are interviewed and assessed before being accepted on the training course. Ten young people are trained at a time over a period of 9-12 months. The trainees are paid and, following the completion of the comprehensive course, graduate with a certificate. They may then work independently or HYT may employ them in social enterprise projects.

HYT will only work where there is a clear demand from the local community

Funding for the training and community buildings is provided mainly through grants and donations although there is increasing income coming from HYT’s social enterprise, constructing buildings, water tanks and sanitation facilities under commission.

Impact

The 139 buildings constructed to date by HYT have improved the lives of over 40,000 people. The water tanks are providing clean water for schools and their associated communities, while addressing health-related sanitation issues with the installation of latrines and wash facilities. In addition, the building work is helping thousands more children access education and enables more teachers to work in schools.

With staff accommodation and a new class room and water tank we have increased the number of pupils from 400 to 690 and attracted some great teachers too. We could not have done this without HYT.

Head Teacher in Uganda

Through its training programme, HYT is creating much needed jobs; to date 91 young Ugandans have graduated from the ISSB training, 69 of whom are involved in further ISSB projects. The income generated is lifting graduates’ families out of poverty and means their children can go to school. Many of the HYT-trained masons have taken their skills back to their own communities and, with the help of a loaned ISSB block press, have been building in their own towns.

With no energy requirements for a kiln, compared to a fired brick the ISSB walling constructed to date is estimated to have saved 240 MWh of energy and 100 tonnes CO2e. Additional savings are made as blocks are produced on site, significantly reducing transport emissions and costs. Other benefits of the new ISSB buildings include reduced rendering of walls, improved ventilation and cooler environments than traditional buildings due to the thermal properties of the ISSB.

Technology

The ISSBs are made on site by mixing subsoil (also known as marram) with 7% cement, water and a small amount of sand. The mixture is then compressed using a high-pressure manual press with the appropriate mould. The blocks are air cured for 28 days and are then ready for use. The bottom few rows of blocks in a building are plastered to protect against water ingress.

A finished school building and water tank

As the blocks interlock, very little mortar is needed in the building process, significantly reducing overall costs and saving more carbon. Mortar is used only in the corners, pillars and columns for strength. The cost of building with ISSBs can be 30% less than using fired bricks, and is quicker too.

Consistency of the blocks is ensured by using the same presses for any one building, rigorous quality control during block making and by ensuring good maintenance of the presses.

The water tanks are essential. Catching the rain means that students don’t have to walk to the borehole to collect water – missing essential education.

Peter from Nabirama Primary School

The future

HYT aims to expand its reach by opening a new hub to increase the number of skilled trainers and masons and therefore increase wider adoption of ISSBs across Uganda. In addition, the social enterprise arm of HYT is growing and there is further potential to offer housing, water tanks and other structures, as well as providing technical expertise and financial sustainability. Based on their experience, HYT would also like to develop a marketing campaign to persuade others of the benefits of ISSB construction.