Assessing the Feasibility of Using Office Building Envelope Optimization Solutions in Temperate Regions of Iran; A Case Study of Zero Energy Buildings in Similar Climates

Air pollution and excessive energy consumption are two crises that seriously threaten metropolises today and endanger the health of society and energy sources in the future. Nearly half of the world’s non-renewable energy resources have been consumed. An energy shortage is inevitable because more than 40% of energy consumption is in the construction sector. The average energy consumption of buildings in Iran is more than 2.5 times the world average, and big cities suffer from air pollution, which is often caused by fossil fuels. More than 98% of the energy in Iran is consumed as oil and gas products, which account for 26.4% of carbon dioxide emissions. The buildings are designed and built in such a way that they do not retain the cold and heat that is provided with exorbitant costs. The heat exchange occurs quickly due to the un-insulated outer envelope (walls, roof, and floor) and un-insulated cooling and heating facilities, which leads to an increase in energy consumption by heating and cooling systems. The energy consumption research in the recent decade comprises sustainable, zero-energy, and zero-carbon buildings. The annual energy consumption of these buildings is nearly zero, and they do not produce carbon pollutants. Considering the non-use of carbon dioxide-producing energies and renewable energy supply, zero-carbon buildings can effectively reduce air pollution in big cities. This research aims to identify and explain the design principles of European zero-energy office building envelopes to reduce energy consumption and carbon emissions. Then it will evaluate the feasibility of using the solutions above in cities with similar climates in Iran.

At first, the principles and solutions of reducing energy consumption, reducing carbon dioxide emissions, and using renewable energies that directly or indirectly affect the design of the building envelope have been identified and specified. Then, to reduce energy consumption, carbon dioxide emission, and the use of renewable energy, 34 examples of office buildings in temperate European regions have been examined, and the most applied methods for designing their envelopes have been identified. Then, the most widely used solutions identified for the feasibility of implementation for office buildings in areas with similar climates in Iran have been weighted by the Shannon entropy method and ranked according to the combined weight of application, feasibility, or based on some parameters such as cost, ease of implementation during construction and after construction, the need for skilled labor and specialized equipment, execution time, the produced energy and payback period of the investment. 

The results of the research show that the most employed solutions are related to the use of photovoltaic panels, thermal insulation of the walls, the use of natural ventilation, attention to the dimensions and position of the windows, the use of daylight, the use of materials with suitable thermal capacity, the use of greenhouse and atrium, and the use of green wall and roof.

The results of this article indicate the most effective principles and common solutions for the envelope design of zero-energy buildings in Iran with climates similar to the European climate. The combined use of these solutions in the design of envelopes can greatly reduce energy consumption and carbon dioxide emissions in the short term. Due to the novel nature of the construction and operation of zero energy buildings in Iran and the lack of experience in obtaining the productivity and energy efficiency of these buildings using various solutions so far, using the experiences of advanced countries and the feasibility of implementing those solutions is indispensable to achieve an optimal and appropriate design and the highest energy efficiency of the buildings in Iran shortly. Therefore, the results of this research can effectively help designers in this field.