C hapter 04: Strateg i es fo r g reen i n g so c i a l ho u si ng
Figure 4.4 Variation in vegetation depending on soil slope
Toyo Greenland, 2009
Figure 4.4 shows that greenery can be used to cover all slopes from roofs to walls. Green roofs require adequate structural support and would require a moderate level of expertise to ensure a long lasting roof. There are generally two types of green roofs: §§ Extensive – Extensive has a build-up height of 50-150mm, light weight and easy to install. Extensive roofs require no irrigation and are low maintenance. Planting is generally moss, sedum, herbs and grasses. §§ Intensive - Intensive roofs have a build-up height of 150mm-1500mm. These roofs require substantial structural support, irrigation, maintenance. Uses include natural gardens, growing food, and recreational space. Intensive roofs are generally flat (GreenSpec, 2013).
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Green building interventions for social housing
Construction of a green roof: the roof structure is covered with a membrane surface that is covered with water proof insulation, which are then covered with plastic sheeting (root barrier). To build up the substrate, pea gravel (drainage layer that directs water from the roof ), a filter fabric keeping material from the drainage layer and an optional water retention fabric on which the mulch and soil base and vegetation layer is placed (UN-Habitat, 2012a).
EcoHouse retrofit case study in Rio de Janeiro, Brazil A case study EcoHouse in Rio aimed to create an environmentally friendly house as an example for other modest EcoHouses in hot and humid climates. The house’s many characteristics featured rainwater harvesting, passive cooling and a green roof.