The Indoor Environmental Quality (IEQ) describes an indoor space condition that the wellbeing and comfortability are provided for the users. Many researchers have highlighted the importance of adopting IEQ criteria, although they are not yet well defined in the Kurdistan region. However, environmental quality is not necessary for the contemporary buildings of the Kurdistan Region, and there is no measurement tool in the Region. This research aims to develop an IEQ assessment tool for the Kurdistan region using Mixed method methodology, both qualitative and quantitative. Therefore, a Delphi Technique was used as a method initially developed as systematic, interactive forecasting on a panel of experts. Thirty-five Delphi Candidates have reached an agreement on selecting the criteria for the IEQ, as Spss and a particular equation has used to find criteria weights. As a result, seven criteria with 22 indicators have been selected by expert ratings. A computer-based tool (KIEQA) has been created based on the scores selected by experts. Research results show that good IEQ is essential for interior design. It also offers a suitable indoor environment for users. This research has many significant advantages since it can raise awareness of issues of indoor environmental quality for architects, experts, and policymakers. Furthermore, to draw up an action plan for existing and new interior design projects in the Kurdistan Region. Future researches may concentrate on the correlation between IEQ criteria and to develop this tool regarding different building typologies.