Abstarct: Abstract In recent decades, increasing energy consumption in the world has caused severe environmental damage. The energy sector is the main source of greenhouse gas emissions leading to global warming, melting of the polar ice caps, and rising sea levels. These climate changes and limited fossil fuel reserves have forced the world to seek alternative energy solutions, and sustainability issues have come to the fore in several sectors. With the building sector accounting for one-third of the world's energy consumption, it is possible to reduce energy consumption and the production of environmental pollutants by applying building optimization solutions. In Iran, which has large fossil energy resources and owns 10% of the world's oil and 15% of gas reserves, less attention has been paid to energy consumption reduction solutions compared to other parts of the world. The average energy intensity in the world is 0.4 and in Iran it is 0.6, which shows the great potential to optimise energy consumption in this country. The aim of this study is to find solutions for reducing heat load in a passive way for Shahrood schools, and on the way to achieve these solutions, first it investigates the architectural parameters that affect the heat load of the building using library resources, and then using simulation in DesignBuilder software, its impact on We have verified the energy consumption of the building. The results show: 1) 1 to 2 proportions with east-west extension and 4 degrees deviation to the east have less energy consumption for Shahrood schools. 2) For double and multiple glazed windows, the thermal performance of xenon gas is better than air, krypton, argon and xenon, so replacing double glazed windows with xenon gas can reduce energy consumption by 9.18% compared to single glazed windows. Comparing single double glazing with low emissivity double glazing (with xenon gas), there is a 3.6% reduction in energy consumption. 4) When comparing thermal insulation materials: expanded polystyrene, extruded polystyrene, polyurethane, mineral fibres and cellulose, we found that polyurethane has a better thermal performance. By installing this insulation with a thickness of 5 cm in the external walls, the heating load decreased by 24.6% and the cooling load increased by 11.8%, so that the total heating load decreased by 20%.