Eco-friendly home construction for returnees in Northern Sri Lanka

UN-Habitat, one of the Implementing Agencies under the Indian Housing Project, is promoting eco-friendly construction techniques for homeowners in Sri Lanka's conflict affected Northern Province as well as assisting with the reduction of construction costs with improved house designs. These eco friendly model houses are being constructed with the aim of educating homeowners and encouraging smarter building practices.

Following the end of three decades of conflict and the subsequent resettlement of Internally Displaced Persons (IDPs) in their villages of origin, construction activities have significantly increased in the Northern Province. This has lead to increasing demand on construction materials including sand and traditional timber varieties. The dearth of building materials has also resulted in escalating costs in the North. Recognising the urgent need to ensure the adequate supply of building materials whilst safeguarding the fragile environment in the North, UN-Habitat is promoting an initiative to construct "eco-friendly model houses".

The UN-Habitat field team has assisted both families to select suitable house plans and provided advice on construction work and building materials. As the project follows a "home owner driven" method of construction, Vasuki and Thangarasa are responsible for the planning, organization and construction of their houses. Both families have been providing their unskilled labour towards the construction process including clearing the land and digging trenches for the foundations and sourcing building materials. Skilled craftsmen have been hired to undertake the major construction work.

The model houses have modern layouts, keeping to the minimum floor area requirements specified by the project. The traditional court yard concept has been modified to adapt to the reduced floor area to improve natural light and ventilation. Thermal comfort is improved from the cross ventilation and new building materials, and trees will be planted to increase shading. The design also allows for future expansion of the house to promote incremental development. Beneficiaries are being trained to practice some of the technologies through practical training programmes at the site which will improve their vocational skills and livelihood opportunities.

The walls of both model houses are being constructed out of cement stabilized earth bricks (CSEB) in place of traditional cement blocks or bricks. CSEB walls are a cost effective and environmental friendly method of house construction. Properly built CSEB walls need no plaster and consume less cement mortar for bonding, thereby reducing sand and cement consumption significantly. These blocks can be produced by beneficiaries themselves, using suitable earth, with a simple manually operated machine. These bricks can also be purchased from the market, in the form of inter-locking bricks and lintel bricks. The houses constructed with stabilised earth bricks are much cooler than houses constructed with other bricks or cement blocks as the soil has a superior cooling effect.

The homeowners will also use treated plantation timber species such as Rubber and Pinus for door and window construction. The treated timbers will be durable and therefore more cost effective in the long run and will not lead to loss of forest cover in the North as these are sourced from plantation forests.

In addition to using alterative building materials, home owners are also practising innovative methods to minimise wastage and construction costs. These methods include using salvaged building materials such as small recycled hard debris for foundations, as well as previously used unbroken tiles and roof timber for roofs. Concrete, tile and brick parts converted to course aggregates of concrete are being used for paving. Beneficiaries have also been trained on correct storage methods of building materials such as sand and cement, thereby eliminating excessive wastage.

Each model house will have a domestic rainwater harvesting unit installed for roof top rainwater collection, ensuring improved access to water during the dry season. Smoke free chimneys and domestic bio gas production units will also be installed in each house. The biogas chamber will be used for biogas production with domestic waste for cooking.

Discussing the construction of her house, Vasuki stated: "I thank the Indian Government for providing this opportunity and UN-Habitat for all the advice and support they are providing in constructing this house using new techniques and materials. We have been able to select cost effective building materials and make savings on overall cost after participating in the UN Habitat awareness programme."