2.4 Sustainable Design

Figure 2-18. South-west Elevation

2.4 Sustainable Design

Our design of the women’s house is concentrated on sustainability by the use of natural resources effectively. Based on the fact that using power is not a cost-efficiency solution to lighting and cooling in rural areas, passive design will be the main system for the buildings. Moreover, to facilitate the self-build and reduce the pollution from construction, we will use the natural materials that are easy to access, manufacture and build as much as possible.

● Passive Design

The inclined and overhead roof allows natural light to come into the house during daytime that minimize the use of artificial lighting (Figure 2-19). The windows and the roof work together to provide natural ventilation and natural lighting to the rooms. It also allows cool wind to come in and bring heat outside the building (Figure 2-18).l

If it is during hot seasons, the window can be closed to reduce the heat light coming in, otherwise, it will be opened for ventilation and cooling. This will minimize the power required during daylight and hot summer time.

Figure 2-19. Passive thermal design Figure 2-20. Passive design for lighting

Figure 2-21. Passive design for Women’s House

In order to limit the light and rainwater to come into the house, as well as to provide protection to the brick wall, the overhang eave is designed in our buildings (Figure 2-21). In addition, the inclined roof not only provides a good illumination for the toilet, but -also creates effective ventilation that can take away the odour from the toilet (Figure 2-22).

Figure 2-22. Passive design for odour in Toilets

● Materials Selection

In terms of achieving sustainability and cost efficiency in our project, we are going to use the local materials for most of our building design. We strongly recommend to make some materials on site.

Figure 2-23. Materials of external building structure

Figure 2-24. Materials of internal building structures.

● Earth Brick Earth Brick is our primary building material. As we are hoping to engage with women in construction work, we found brick making is a cheap, easy and proven technique to be used in our building. The bricks in Senegal are commonly air dried with a mix of earth, grass, clay and sand and they can be done by women. Then the women can easily learn how to manufacture the brick and do the bricklaying jobs. Therefore, our project will use the brick for free.

● Concrete Due to the potential flood issue and soft soil geographic condition, we decided to use concrete for our footing as it enhances the strength of our footing for geographic changes. The concrete might be expensive for transportation, so hand-mix concrete on site can reduce its cost. Besides, we will consider using the reinforcement bar and tie to work together with the concrete in our footing if those materials are accessible in Baghere and women can be trained to undertake the job for reinforcement installation.

● Bamboo We use bamboo for our window and door as bamboo is one of the natural resources in Baghere. Also, bamboo is a feature of local architecture so that using bamboo can represent the traditions of Baghere. Furthermore, bamboo weaving skills can be taught to local women and allow them to engage in providing building elements and earn a living (Figure 2-27).

Besides, bamboo gutters are used in this design to reflect a green and sustainable concept by collecting rainwater to reuse (Figure 2-28).

Figure 2-28. Bamboo gutter ("giant grass builds bamboo cubby house from recycled materials, 2021)

● Earth Due to the flooding and economic issue, we will use earth to do a higher level of slab (at least 300mm above ground floor) with a cement screeding for waterproofing. Flooring by earth and cement will be a suitable work for women to carry out.

● Timber As timber has a longer life than bamboo, we design to use timber for the roof truss because it is strong enough to support our roof structure. Normally, the timber trusses should be prefabricated by carpenters and then transported to the site. However, due to high transportation costs, the trusses can be made on site by workers or women who undertake proper training. In addition, the timber door frame and window frame replace the bamboo framing because timber is easier to cut and shape (Figure 2-28).

Figure 2-29. Bamboo weaving doors with timber frame ("Rustic Retreat - Rustic - Garage - Other - by Timberframe Horizons, LLC" , 2021)

● Aluminum In order to collect the rainwater, we design an incline aluminium for roof sheeting to integrate with the bamboo gutter. The wavy configuration of the aluminium facilitates the rainwater to flow down (Figure 2-30). Also, aluminum is also a suitable material for passive thermal design as it can reflect the light and heat.

Figure 2-30. Aluminium for roofing Figure 2-31. Thatch for pavilion roof