Job Description
Principal Mechanical Design EngineerLocation: Hertford, Hertfordshire (office-based with hybrid after probation) Salary: upto 75,000 depending on experience Type: Permanent, full-timeThe OpportunityOur client is an established, multidisciplinary building services consultancy based in Hertfordshire. Founded over two decades ago, they have built a strong reputation as M&E Consulting Engineers and Low Carbon Consultants, delivering technically excellent design solutions for architects, contractors, and end clients across commercial offices, education, healthcare, data centres, and historic buildings.This is a Principal-level appointment into a tight, growing team that values technical depth, collaborative problem-solving, and proper engineering discipline. They are looking for a mechanical engineer who is genuinely strong on full design, not just concept work, who knows their RIBA stages inside out, and who is ready to take technical leadership on projects and mentor the wider team.Key ResponsibilitiesTake principal-level technical responsibility for mechanical design on live projects across RIBA Stages 1 to 4, from inception through to detail designOwn and deliver full mechanical design packages, including HVAC, public health, plantroom layouts, load calculations, specifications, and schedulesDevelop low-carbon and energy-efficient mechanical strategies aligned with current Building Regulations, CIBSE guidance, and British StandardsLead client engagement on assigned projects, presenting design rationale and managing expectations from concept through to deliveryCoordinate multidisciplinary inputs with architects, electrical engineers, structural engineers, and contractorsProvide technical leadership and mentoring to senior, intermediate, and junior mechanical engineers within the teamReview and sign off design output, ensuring technical accuracy, compliance, and consistency across the consultancyContribute to fee proposals, project programming, resource planning, and business development activityCarry out site inspections, condition surveys, and commissioning support as requiredUphold and shape the consultancy's reputation for technical excellence and sustainability-led designAbout YouSignificant experience as a Mechanical Design Engineer within a UK building services consultancy environment, with a track record at Senior or Principal levelStrong, demonstrable understanding of RIBA Stages 1 to 4, with particular depth in detail design (Stage 4)Confident producing fully coordinated mechanical designs across HVAC, public health, ventilation, heating, cooling, and plantroom systemsWorking knowledge of energy modelling tools (IES VE or similar) and design software (AutoCAD, Revit MEP)Proven ability to lead client relationships, present design solutions, and manage commercial expectationsExperience mentoring and technically supporting junior and intermediate engineersCommercially aware, with an understanding of fee management, project programmes, and resource planningChartered or working towards chartership (CEng, MCIBSE) is desirableUK right to workLocal to Hertfordshire or within a sensible commuteYou will thrive in this role if you want technical leadership, ownership of your projects, visibility on your work, and the chance to shape the direction of a growing consultancy that genuinely cares about engineering quality and sustainability.Package£75,000 basic salary depending on experienceHybrid working available after successful completion of probationPension and benefits packageClear progression path within a growing consultancyActive CPD culture and full support towards chartershipMentoring and leadership development as part of the roleTPBN1_UKTJ