The construction industry is subjected to more risk and uncertainty than many other industries, in addition to poor risk-tracking records. This usually causes the late completion of projects, surpassing their estimated budgets even without achieving the desired quality and operational requirements. This study first identified the most critical factors affecting the accuracy of cost estimates. A questionnaire has been designed and distributed to construction experts; the results indicated stakeholders’ perception to improve their cost estimation using a proper and predefined risk management plan. Following the respondents’ judgment, this study identified 51 risk factors and their potential root causes and presents a response plan for the most critical risks that might affect cost estimates to improve construction-industry performance. Then, a new simple model has been developed to analyze risk factors affecting the accuracy of conceptual cost estimates, from both clients’ and contractors’ perspectives. The developed model will provide the decision-makers with a list of risks accompanied by guidelines/response plans to mitigate their effect on project cost to help the estimators identify the most effective cost contingency against the project’s scope creep.