Principal Mechanical Design Engineer

Principal Mechanical Design Engineer Location: Hertford, Hertfordshire (office-based with hybrid after probation) Salary: upto 75,000 depending on experience Type: Permanent, full-time The Opportunity Our client is an established, multidisciplinary building services consultancy based in Hertfordshire.

If you are interested in applying for this job, please make sure you meet the following requirements as listed below.

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 Responsibilities Take principal-level technical responsibility for mechanical design on live projects across RIBA Stages 1 to 4, from inception through to detail design Own and deliver full mechanical design packages, including HVAC, public health, plantroom layouts, load calculations, specifications, and schedules Develop low-carbon and energy-efficient mechanical strategies aligned with current Building Regulations, CIBSE guidance, and British Standards Lead client engagement on assigned projects, presenting design rationale and managing expectations from concept through to delivery Coordinate multidisciplinary inputs with architects, electrical engineers, structural engineers, and contractors Provide technical leadership and mentoring to senior, intermediate, and junior mechanical engineers within the team Review and sign off design output, ensuring technical accuracy, compliance, and consistency across the consultancy Contribute to fee proposals, project programming, resource planning, and business development activity Carry out site inspections, condition surveys, and commissioning support as required Uphold and shape the consultancy's reputation for technical excellence and sustainability-led design About You Significant experience as a Mechanical Design Engineer within a UK building services consultancy environment, with a track record at Senior or Principal level Strong, 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 systems Working 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 xwzovoh commercial expectations Experience mentoring and technically supporting junior and intermediate engineers Commercially aware, with an understanding of fee management, project programmes, and resource planning Chartered or working towards chartership (CEng, MCIBSE) is desirable UK right to work Local to Hertfordshire or within a sensible commute You 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 experience Hybrid working available after successful completion of probation Pension and benefits package Clear progression path within a growing consultancy Active CPD culture and full support towards chartership Mentoring and leadership development as part of the role