Improving Iranian National Standard (INS) Indices for building energy performance through comparing with LEED Standard: Case Study of Office Buildings in Tehran

The aim of this study was to compare the Iranian National Standard (INS) with LEED, a valid international standard, in the field of energy performance evaluation of buildings to show the strengths and weaknesses of INS and then improve and update it in this area. For this purpose, a government office building in Tehran was selected as the case study. To evaluate the energy performance of this building in accordance with the guideline of LEED standard, at first all its components and equipment were modeled and simulated in Design Builder software based on the ASHRAE standard 90.1. Then, the baseline and proposed models of the ASHRAE standard were configured for the case building, and their annual energy consumption and cost were compared with each other. The simulation results showed that the proposed model of the case building can save 31.5% annually the cost of energy consumption, and can achieve 13 out of 18 points of LEED standard in the category of energy performance. Afterwards, this proposed model of ASHRAE was evaluated by INS to determine the energy consumption criteria and energy label guidelines for non-residential buildings. As the annual energy consumption of the proposed model for the case building in this study was 73 kWh/m2, the energy ratio index (R) for this building, based on INS, was less than one that received label A in energy rating. Findings of this research revealed that in order to receive the highest LEED score in the category of energy performance for an office building, it is necessary to use valid standards, as LEED is far beyond INS in energy conservation, prevention of carbon dioxide emissions, and environmental protection. To improve INS in the category of energy performance for office buildings and to be in line with the LEED standard, this paper recommends a 23% reduction in the energy consumption index of ideal non-residential buildings in Tehran, and also improvement of this index for the other climates in Iran.