It is a basic value on the basis of which the real estate tax and others are calculated. It is also an important element to complete the sale and purchase of real estate. The popular value of the property is seen as the value under which Turkish law deals with the property. The popular allowance for real estate has a direct relationship to the real estate tax in Turkey because it consists of the value of immovable property that changes from year to year according to market conditions and according to supply and demand. It is legally defined as the value of immovable property intended for sale, which is assessed in accordance with the provisions of the state law to determine values. “Popular or fair value” is the most important element in determining the price of the property when buying or selling, as the selling price of the property may not be less than the popular value determined by a committee appointed by the Presidency of the State, after the evaluation decision is issued and sent to the states by the Ministry of Finance. The allowance for joint ownership is calculated based on several considerations, including: Current Market Value: The value of the property in the current market, is affected by factors such as supply and demand, city, neighborhood, residential sector, street, and transportation. On the basis of the real estate tax value in Turkey: It is considered the minimum value of the property, which is generally less than the market value of the property, on the basis of which the real estate tax is calculated. How is the common property allowance calculated? If we want to calculate the fair or popular price of a property or a house for example, we must take into account information such as the area, and the popular value of at least three other properties, and these three properties must be located in the same neighborhood as the requested house. The method of calculation is as follows: The value of the popular allowance per square meter in the neighborhood in which the house is located is calculated by dividing the sum of the fair/popular allowance values for the three houses by the sum of the areas of the three houses. Therefore, the approximate value of the trending price of the house is the sum of the trend value per square meter in the neighborhood multiplied by the area of the home for which the trend value will be determined.