Now, the world saw the biggest increase in its population in history, thus increased the use of the land and shrinking green areas in the city, oil crisis, daily activities’ pollution, global warming, and the depletion of natural resources. All these made our cities suffer from environmental problems and one of the most important of these problems is urban heat island.
There are many reasons for an urban heat island, where the city is a rough surface and thus absorb more solar energy, building envelope materials and urban areas for pavement and roofs have a low albedo and a high capacity to store heat, There is also few evapotranspiration (for example, lack of green spaces) in urban areas and a lower cooling by the wind or by radiative exchanges with the sky. These reasons made urban area higher temperatures than in rural areas.
This study related to the materials used for building’s envelope and substructure, which consider proper material to design correct shapes for building envelop and urban space to decrease the effect of UHI.
To achieve this goal, different types of materials will be tested, depending on the surface exposure to sun or sky to find the proper material to decrease the effect of UHI and achieve energy efficient. A partnership is in progress to obtain the optical characteristics of a large range of concretes.
The objectives are: To understand the urban environmental problems’ specifically urban heat island. To identify the factors which contribute to a successful urban form. To analyse the effects of construction materials to ensure energy save for buildings and comfort in outdoor spaces.
In order to conduct this research, there are 4 main steps:
– Choose of study cases (urban forms that are realistic and representative enough and materials used in cities or new materials),
– Build the experience plan,
– Carry out the simulations (Solene-microclimat) and
– Analyses all the results and Propose guidelines both for buildings envelopes and substructure materials.