Your new company You'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 role As 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 mechanical team. What you'll need to succeed A degree, HNC or HND in Mechanical or Building Services Engineering Strong experience in mechanical building services design at a senior or principal level Proficiency in design software such as Revit, Amtech, Relux/Dialux and Microsoft Office Strong understanding of British Standards, Building Regulations and industry best practice Proven ability to engage with clients, lead meetings and influence design direction Experience integrating low‑carbon, renewable and energy‑efficient systems Awareness of BREEAM and broader sustainability frameworks Understanding of electrical interfaces to support multidisciplinary coordination Professional membership (e.g., CIBSE or IMechE) or active progression toward Chartership Confident communicator with leadership skills and a collaborative approach What you'll get in return Salary between £55,000 and £65,000, dependent on experience and seniority Structured progression pathways and strong CPD/Chartership support Agile and flexible working arrangements Generous holiday entitlement with opportunities to buy or sell leave Enhanced sickness, maternity, paternity and family‑friendly policies Exposure to complex, interesting and sustainability‑focused project work Cycle‑to‑work and electric vehicle schemes Eye care support, Employee Assistance Programme and funded team‑building activities Referral bonuses and broader staff benefits Opportunities to take part in charitable, social and community initiatives What you need to do now If you're interested in this role, click 'apply now' to forward an up-to-date copy of your CV, or call us now. If this job isn't quite right for you, but you are looking for a new position, please contact us for a confidential discussion about your career. Hays Specialist Recruitment Limited acts as an employment agency for permanent recruitment and employment business for the supply of temporary workers. By applying for this job you accept the T&C's, Privacy Policy and Disclaimers which can be found at hays.co.uk