Your new companyYou''ll be joining a well-established building services consultancy recognised for delivering technically strong, sustainable and low-carbon engineering solutions. The Derby office supports a wide mix of projects across commercial, residential, healthcare, education, industrial and public sector schemes. This is a collaborative, people-focused environment where senior leaders are encouraged to influence strategy, mentor others and shape the future development of the team.Your new roleAs a Principal Mechanical Design Engineer, you will take a leading role in guiding project delivery, raising technical standards and representing the consultancy at a senior level. You will oversee mechanical design work from early concept through to completion, ensuring accuracy, coordination and robust engineering outcomes across multiple projects.You''ll act as a trusted contact for key clients, chair and contribute to design meetings, and support the growth and development of junior and intermediate engineers. Your work will include reviewing and producing calculations, drawings and specifications, setting design strategies, selecting appropriate plant and technologies, and ensuring low-carbon and sustainable principles are embedded in every solution.The role also involves attending site inspections, supporting quality assurance, helping to secure repeat business through strong client relationships, and playing a central role in the ongoing technical development of the mechani