The idea is to prototype 2 cyclone resistant houses built by local people and materials, which are low carbon and affordable for the poor.
Along Bangladesh’s expansive and populous coast, tens of thousands of families lose their homes to extreme weather events such as tropical cyclones every year. Between 1980 and 2008, the country experienced 219 natural disasters causing US$16b in damages - a great proportion of which was accounted for in destroyed homesteads. On an average, 0.3 million houses are damaged annually due to disasters in Bangladesh, with those numbers expected to climb higher as climate change takes its toll.
Two of every three houses in rural Bangladesh are made of non-concrete materials, which make them highly vulnerable to disasters. UNDP estimates that low-cost housing designed to take into account the onslaught of storms and cyclones can not only reduce post disaster loss by up to half but also contribute to poverty alleviation through post-disaster cost savings for the house owners.
We’re aiming to design and build two multi-storied rural houses built by local people with local materials that (a) are resilient to cyclone and flooding, (b) are built with low carbon features and with incurring a low cost. The innovative feature in this case is how a house could be built in extreme climate vulnerable areas for most vulnerable people within the cost that poor people or government can afford and can be scaled up for poor people with minimum carbon consumption. This will provide climate-economic-social solutions.
The Bangladesh government has keen interest & growing investment in rural housing, particularly for disaster affected people. However, government wants a solution such that in rural Bangladesh increasing housing demand does not accommodate more croplands, and are built with low carbon consumption and build in such a way that they can stand while cyclone and tidal flooding affect the rural areas.
Category of the action
Mitigation/Adaptation, Changing public attitudes about climate change
What actions do you propose?
The project aims to protect the most vulnerable coastal-dwelling from the impacts of climate change by innovating housing solutions for poor people living in climate vulnerable locations in Bangladesh. It will fund construction of 2 houses with technological, economic and social innovation.
Structure of the houses
The houses will be around 700 square feet in size each, comprising of two floors connected by a common stairway. Each house will accommodate two families, and each of the two units will comprise of two bedrooms, one toilet with a bath, and a common living/ dining space.
How is the house low carbon?
In designing this house one of the main considerations was to lower the carbon footprint. As such as the materials to be used will mostly be those of low carbon content. In the core structure, instead of using cement or concrete pillars, we are proposing the use of locally available timber. Considering climatic disasters such as cyclone and salinity, only the footing of house will be constructed with Steel Frame painted with Bitumen while the rest will be made of timber. To strengthen the core structure against strong winds, inverted V bracing will be used which will also be made of locally available timber/bamboo. The plinth will be made of locally available clay, which does not contribute to carbon emissions. The façade will also be constructed of locally available bamboo/wood which is totally carbon free. Moreover, since very minimum materials need to be transported from elsewhere, the carbon emission that would have happened through the use of vehicles can also be eliminated, thus making the construction process environmentally friendly with possible extent low carbon build.
Energy efficiency/Green features:
Renewable energy usage – The houses will have solar panels on their roof. These will be angled towards the South West as maximum sunlight can be captured in that direction. The area of the panels would be 450 square feet. The AC-DC inverter will be on the roof, connected to both units.
Rainwater harvesting and storage – While the clear height (floor to ceiling) will be 10 feet in the rest of the house, this height will be only 7 feet in the kitchen and toilet area, to accommodate a rainwater harvesting and storage tank in the remaining 3 feet space inside the plinth. The tank will have dimensions of 365 cubic feet and can store up to 10 litres of water. The water from the roof would accumulate in the tank via pipes which will also have a filtering equipment installed. The force of gravity would then enable the flow of water from the tank to the rest of the house. Two collecting points will be use to ensure supply of water for both families. The tank would be portable and easy to clean.
What features make the house climate resilient?
Resilience is the capacity to adapt to changing conditions and to maintain or regain functionality in the face of stress or disturbance. In this context, the house has the following features:
1. Simple Design & Public Participation – Simple systems are more resilient than complex ones, as such the structure of the house is designed to be as simple as possible, with easy construction and repairing techniques, taking the rural people’s preferences in consideration.
2. Crisis preparedness - Core essential elements like Water and Electricity are incorporated in house design as dedicated Rainwater Harvesting System and Alternate Energy/Solar Energy is provided for every unit. Moreover, the plinth height will be raised 5 feet to reduce risk of flooding and waterlogging.
3. Dependence on Local Ecosystem, Materials & Technology - The building materials used are locally available and the construction techniques followed are locally practiced.
4. Flexibility of Façade – Only the basic technology for façade construction will be designed, allowing flexibility to the users to choose building materials according their choice or economic condition. Thus the core structure will be resilient but will also develop a sense of belonging of the residents to the house.
5. Dealing with climate change exposures: high speed wind, tidal surge and saline water
Wind: The house will be rectangular in shape and the shorter edge will be facing the direction of the wind which will reduce overall wind exposure. Secondly, the side of the roof with the greater slope will be faced towards the wind and the roof will not extend beyond the wall which will allow the wind to pass over the roof without affecting the core structure. Moreover, the roof will only be attached to the core structure and will not be supported by any walls so even if the roof is affected the walls will not be. Furthermore, there would be some gaps between the wall surface and the roof so when the wind hits the roof the thrust will be reduced. Inverted V bracing will be used for the façade and bitumen painted steel frame will be used which will increase its resistance to wind.
Tidal Surge: The plinth will be raised by 5 feet to reduce risk of tidal surge, flooding and waterlogging. The base of the plinth will be made of mud and will be covered a layer of jute compost which will make the plinth of the building resistant to tidal surge.
Salinity: In addition to the tidal surge measures, the following measures will be taken to reduce salinity exposure. The core structure will be made of saline tolerant wood. The part of the column which will be inside the plinth will be painted with bitumen which is saline resilient.
6. Dealing with sensitivity of the construction materials to climate variabilities- Following discussion with the community people and testing of various materials, the construction materials will be selected which are highly resilient or less sensitive to water, humidity, salinity and woodworms.
What features of the house make the economic costs low?
All materials are locally available and the house can be constructed locally. No outside expert mason is required for construction and no material is needed to be imported, which will largely cut down the transportation and overall construction cost. Reconstruction/repairing is also convenient as materials are locally and can be fixed easily even by the house dweller, making maintenance costs low. The cost of ESP Sandwich Panel, which will be used as roof is also very low and have inbuilt thermal insulation functions to reduce heat. The total cost for each house will be around 8400, of which the owner (rural poor) will contribute 1400 USD equivalent materials and this innovation project will contribute 7000 USD.
The project aims to attain the following outcomes:
· A homegrown design for coastal homesteads that can withstand extreme weather events, and can be adopted by the national housing programmes and future development projects.
· Support 1 million coastal inhabitants by scaling up the prototype success to live in the relative security that their houses will withstand tropical cyclones and spare them the frequent expenses of rebuilding.
· Promote an innovative model for resilient houses based on lessons and best practices from past projects in Bangladesh. Salient structural safety design will be based on 100 years track record of tidal surge, 215 km/per hour wind safety measures, and saline proof structures. The constructed houses will apply renewable energy, rainwater harvesting, and access to cyclone early warning systems.
· Demonstrate the value of and methods for resilient housing to other stakeholders including private sector developers and more affluent segments of society to incentivize them to invest in resilient rural housing.
The project will be designed with transformative social potential. It will empower people through (a) ownership of resilient housing with its strong potential for social transformation, especially for landless poor; (b) providing housing as the core asset on which poor people build on. The sole or joint entitlement of the resilient houses would empower women and help them to address other aspects of gender inequality. The advocacy activities and mechanisms to include landless people in the direct beneficiary pool would also create windows to address some deeply rooted social inequalities.
Besides offering structural safety and lowering physical risks, the resilient houses would be comprehensive housing units with co-benefits of low carbon energy sources, safe water and sanitation options as well as home-based income generation and livelihood opportunities. The land use planning for resilient rural housing would also help address the decrease in agricultural land and productivity caused by unplanned housing. Rural houses able to withstand disaster events would also divert significant public and private expenditure from post-disaster recovery to essential human development.
The project will adopt “owner-driven approach” for resilient homes that will increase human capacity by factoring in social and gender inclusiveness, enhancing privacy and dignity. The use of solar to supply energy for household consumption would offer climate benefits. The rainwater harvesting facility would ensure availability of safe water. A home based water and sanitation facility would greatly improve family health and reduce women’s burden for water collection and health care.
The project would indirectly benefit many coastal people by saving lives and assets from cyclonic wind, tidal surge and inundation and providing 'safe haven’ for neighboring communities during extreme events. Climate-smart structure with adaptation (income opportunity, robust structure) and mitigation (low carbon construction, renewable energy source) co-benefits will aid poor people comprehensively. The project will transfer skills, knowledge and technology, which would make a demonstration effect on wider communities.
The construction of homes will create climate adaptive livelihood opportunities for day laborers, bar binders, masons with skill development and sustained opportunities. Thus, aggregately the resilient homes would protect life and assets from extreme climate induced events, enhance adaptive capacities, uplift people from extreme poverty and enable human development.
 This approach utilizes participatory methods in which house owners play the lead role in the construction while implementing agencies play the support role.
Who will take these actions?
The implementing entity of this project will be UNDP Bangladesh Country Office while the executing agency will be the Bangladesh Government’s (GoB) Ministry of Disaster Management and Relief (MoDMR). UNDP will manage the funds and technical quality of the innovation work. The fund will be utilized based on a work plan.
GoB will designate a member in this innovation project team who will be engaged in the whole process of the innovation, so that this can be shared with other colleagues of the ministry for a wider scale up. UNDP will designate a person to lead the innovation team along with GoB and other stakeholders on the ground.
The Project Team will monitor implementation progress, and share the innovation result and process with government departments and the UNDP.
Where will these actions be taken?
The project will be implemented in two villages in highly climate change impacted areas in coastal Bangladesh. The villages will be selected considering the level of climatic hazard exposure, the percentage of the population living in extreme poverty, and the presence of highly fragile housing structures due to climatic disasters. The selected villages will be from the worst five districts in the country with respect to rates of low-quality, non-durable housing, as documented by the UNICEF’s Child Equity Atlas (2013).
What are other key benefits?
The project would empower people through (a) ownership of resilient housing with its strong potential for social transformation, especially for landless poor; (b) providing housing as the core asset on which poor people build.
The sole or joint entitlement of the resilient houses would help address gender equality. The advocacy and mechanisms to include landless people in the direct beneficiary pool would also create windows to address some deeply rooted social inequalities.
Moreover, the project would influence in making National Rural Housing Policy and practices responsive to climate change. Access to finance by the poor for rural housing will be ensured. Institutional capacity for research and development will also be enhanced as a part of the project.
Furthermore, the project will create incentives for private sector, particularly construction, solar, water and sanitation and financing institutions to engage in rural housing to create a wider impact.
What are the proposal’s costs?
The budget breakdown of the project is given below:
Research and Design USD 2500
Construction of two multi-stored houses USD 14000
Documentation and Visibility and Campaign USD 2000
Travel and Accommodation USD 1500
Total USD 20000
Detailed Tentative Budget of Construction of One Unit Prototype House (Will be finalized after the applied innovation research on the ground with people)
Roof (ESP Sandwich Panel)
750sq.ft @/sq.ft= 112500BDT= USD 1450
Timber Post (Burmese Iron Wood/ Local Resilient Wood)
Structural Post - 150 mm (6”) diameter
Non-Structural Post - 100mm (3/4”) diameter
Timber for the post (column) should be selected on the basis of strength and appearance. Timber posts should be well seasoned and treated with preservative. The lower part which will go under plinth level should be properly treated with bitumen. With current best knowledge, the Burmese Iron Wood, which is available in Bangladesh local market can be an option, which cost BDT 16000 per 20 ft’ column. One two storied house will need 12 columns, therefore, the total cost of column for one house will be
BDT 14000/column x 12 column = BDT 168000 = USD 2150
Bitumen painted 100mm Girth 6m Steel Frame
20pc x USD 30 per pc = 600 USD
Clay Foundation of the Floor (5ft depth, 30 ft length, and 24 ft width= 3600 cft)
BDT 10/cft x 3600 cft = BDT 720000 = USD 360
Other Housing Materials
Door (Contributed by the owner) Equivalent to USD 200
Window (Contributed by the owner) Equivalent to USD 100
Staircase (Contributed by the owner) Equivalent to USD 300
Solar Panel USD 400
Rain Water Harvester USD 300
Inverted V Bracing (Contributed by the owner) Equivalent to USD 200
Floor (Wooden) (Contributed by the owner) Equivalent to USD 600
Building Façade USD 540
Mason's Cost USD 1000
Screw, Joist, and other small equipment (Lump sum)USD 200
Total Cost of One House USD 8400
USD 1400 + USD 7000
(Owner Contribution) (Innovation Support)
The timetable showing major scheduled achievements and completion for each of the major components of the project is as follows.
· Inception and project set-up phase: August 2015 to September 2015.
· Technological Research and Innovation Component: September 2015-January 2016.
· Construction of two houses as per design March - May 2016.
· Demonstration and Process Documentation: August 2015-June 2016.
Closure of the project: July 2016.
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