Introduction

The ever increasing population and the expanding urban life along with the limited energy resources have led humans to seek ways of preventing the waste of energy .in addition , in recent years, proper usage of energy resources and the prevention of its waste have become highly important  in all human societies including our beloved country iran. The building and construction industry,with a 35% share in energy consumption, is in need of the right solutions for controlling its usage.
According to statements made by the nations Energy Consumption Optimization Organization. The rate of energy consumption in iranian buildings is approximately 2.5 times the world standards.
Nowadays,energy consumption in buildings can be reduced up to 60% using proper design and insulation.Based on researches done approximately 40% of loss in heat energy in buildings is through doors and windows.This loss can be reduced considrrably with a suitable design and the use of insulated doors and windows.
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