As a civil engineer with around three years of experience, I prioritize clear and proactive communication with contractors when facing unexpected design changes. First, I gather all relevant information and potential impacts of the changes. Then, I arrange a quick on-site meeting to discuss the issues, ensuring all key stakeholders are present. I use visual aids, like sketches or BIM models, to illustrate changes clearly. Listening actively to their concerns is crucial, as it fosters collaboration. I also follow up with a summary email, documenting decisions and action items to ensure everyone is aligned and accountable, minimizing misunderstandings moving forward.