Principal Mechanical Design Engineer Location: Derby Agile / Hybrid Working Salary: Competitive + Bonus + Excellent BenefitsLead Mechanical Design on Complex, Low-Carbon Building ProjectsThis is a key hire within a growing building services consultancy, offering the opportunity to take ownership of mechanical design delivery across technically challenging, multi-sector projects.You will operate as a project leader and technical authority, influencing design standards, mentoring engineers, and working directly with clients across the full project lifecycle.With a strong pipeline of sustainable, design-led projects, this role offers both technical depth and clear progression into senior leadership.What's on OfferClear progression pathway into senior leadershipAgile / flexible working modelGenerous annual leave (with buy/sell options)Enhanced family leave policiesCycle to Work and Electric Vehicle schemesEmployee Assistance Programme and wellbeing supportExposure to technically challenging, sustainability-focused projectsRegular team, social, and charitable initiativesThe RoleLead mechanical design delivery across projects, from concept through to completionAct as Project Leader, managing design coordination and client interactionProduce and oversee calculations, specifications, and detailed design outputsDrive technical excellence within the team, mentoring junior engineersContribute to low-carbon and sustainable design strategies, including renewable integrationAttend and lead client and design team meetings, influencing key decisionsSupport ongoing client relationships and repeat business developmentAbout YouEssential:Degree (or HNC/HND with experience) in Mechanical or Building Services EngineeringProven experience in mechanical design within building services consultancyStrong knowledge of HVAC systems, building regulations, and British/European standardsExperience using design tools such as Revit, Amtech, Relux/DialuxAbility to lead projects and coordinate within multi-disciplinary MEP teamsStrong communication skills with client-facing experienceDesirable:Working towards or achieved Chartered status (CIBSE/IET)Experience across sectors such as healthcare (HTMs), commercial, or residentialKnowledge of BREEAM and sustainable building design principlesUnderstanding of renewable technologies and embedded generation systemsBroad awareness of electrical systems to support multidisciplinary collaborationThe OpportunityStep into a Principal-level role with real project ownership and influenceWork on diverse, technically complex projects across multiple sectorsPlay a key role in delivering low-carbon and net-zero building solutionsDevelop into a senior leadership or client-facing strategic roleJoin a consultancy where engineers have autonomy and visibility across projectsThe CompanyA well-established, multi-disciplinary engineering consultancy delivering mechanical, electrical, and low-carbon design solutions across the UK and internationally. With a strong reputation for technical quality, collaboration, and sustainable design, the business works across sectors including healthcare, education, residential, commercial, and industrial.Engineers here benefit from high levels of autonomy, a supportive culture, and genuine career development opportunities within a growing organisation.ApplyIf you are a Mechanical Design Engineer ready to step into a Principal-level role with greater ownership, influence, and progression, apply now or get in touch for a confidential discussion.