Strategies and Techniques for Optimized Design of Façade in High-rise Buildings: An Energy-Efficient Approach: A Case Study in a Residential Tower Located in Urban District 22, Tehran, Iran

Abstract

A substantial portion of energy consumption by buildings is through its dissipation via building façade. All over the world, relatively 50% of the energy resources are utilized to create a “comfort zone” inside buildings; a splendid goal that, if realized, can play a significant role in reducing energy waste. This is the underlying idea which prompted the present study to search for systematic solutions for energy waste by buildings. In Iran, designer architects have restricted the design of building façade solely to the placement of openings and selection of material type regardless of the fact that building façade plays a major role as a mediator for energy exchange between interior and exterior spaces of a building. The present study aims at obtaining practical solutions for designing façade in high-rise buildings in Tehran through emphasizing on energy saving, which is one of the three main categories associated with designing in sustainable architecture. To do so, related literature and studies in different climates and similar buildings in this regard are reviewed initially and technical and theoretical strategies and propositions are, then, dealt with. In order to improve and adapt the proposed strategies to the available technologies and climatic conditions, these two variables are studied more exclusively. The method adopted as the major method of investigation is case study in addition to a combination of techniques which is discussed later. To analyze the obtained data, multiple document sources are used which account for qualitative research method. Therefore, existing potentials are evaluated to be adapted to the new strategies. These potentials as asserted in upstream documents and laws, specify the possibility of adjustment to the technical and theoretical strategies and predict the outcomes. By analyzing the case study and creating adaptability between the obtained results, it became clear that installing PV windows not only reduced heat consumption by 30%, but also it lowered the need for consuming electricity up to 54% via controlling building illumination. Moreover, it was realized that a series of variables such as: window type, building orientation, area under cover of the building units, placement of internal windows, in addition to electricity consumption and environmental load on each unit determine the amount of cooling load in summer. Therefore, the type of glass applied was assessed and it was concluded that glazed glass with shading coefficient of 0.025 is expected to reduce the cooling load significantly. It means that by using glass with a low index of shading coefficient, fewer amount of energy would be required during hot seasons.