In the design process has a relationship with activity to develop project cost estimate, cause is the final design period includes that activity a whole design sistematicaly to take drawings and spesification, that be major infonnation data to develop project cost estimate. However, in reality many problems through in the design period is badly preparing in the drawings and spesitication process, it because badly knowledge and experience designer in the construction process and constmction method. So that importance of construction opinion by involving knowledge and experience construction project in the design period can be increasing of the construction project and effectivity construction cost.The purpose of this research is to Find owner estimate quality by increasing final design involving the knowledge and experience construction project in the design process. The research shows that factors can beinfluence with the owner estimate quality is to take details of drawing as an infomation project quantity and preparing bid contract that includes with project scope.